135e6168fSJeff Roberson /*- 28a36da99SPedro F. Giffuni * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 38a36da99SPedro F. Giffuni * 4e7d50326SJeff Roberson * Copyright (c) 2002-2007, Jeffrey Roberson <jeff@freebsd.org> 535e6168fSJeff Roberson * All rights reserved. 635e6168fSJeff Roberson * 735e6168fSJeff Roberson * Redistribution and use in source and binary forms, with or without 835e6168fSJeff Roberson * modification, are permitted provided that the following conditions 935e6168fSJeff Roberson * are met: 1035e6168fSJeff Roberson * 1. Redistributions of source code must retain the above copyright 1135e6168fSJeff Roberson * notice unmodified, this list of conditions, and the following 1235e6168fSJeff Roberson * disclaimer. 1335e6168fSJeff Roberson * 2. Redistributions in binary form must reproduce the above copyright 1435e6168fSJeff Roberson * notice, this list of conditions and the following disclaimer in the 1535e6168fSJeff Roberson * documentation and/or other materials provided with the distribution. 1635e6168fSJeff Roberson * 1735e6168fSJeff Roberson * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 1835e6168fSJeff Roberson * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 1935e6168fSJeff Roberson * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 2035e6168fSJeff Roberson * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 2135e6168fSJeff Roberson * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 2235e6168fSJeff Roberson * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 2335e6168fSJeff Roberson * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 2435e6168fSJeff Roberson * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 2535e6168fSJeff Roberson * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 2635e6168fSJeff Roberson * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 2735e6168fSJeff Roberson */ 2835e6168fSJeff Roberson 29ae7a6b38SJeff Roberson /* 30ae7a6b38SJeff Roberson * This file implements the ULE scheduler. ULE supports independent CPU 31ae7a6b38SJeff Roberson * run queues and fine grain locking. It has superior interactive 32ae7a6b38SJeff Roberson * performance under load even on uni-processor systems. 33ae7a6b38SJeff Roberson * 34ae7a6b38SJeff Roberson * etymology: 35a5423ea3SJeff Roberson * ULE is the last three letters in schedule. It owes its name to a 36ae7a6b38SJeff Roberson * generic user created for a scheduling system by Paul Mikesell at 37ae7a6b38SJeff Roberson * Isilon Systems and a general lack of creativity on the part of the author. 38ae7a6b38SJeff Roberson */ 39ae7a6b38SJeff Roberson 40677b542eSDavid E. O'Brien #include <sys/cdefs.h> 41113dda8aSJeff Roberson __FBSDID("$FreeBSD$"); 42677b542eSDavid E. O'Brien 434da0d332SPeter Wemm #include "opt_hwpmc_hooks.h" 444da0d332SPeter Wemm #include "opt_sched.h" 459923b511SScott Long 4635e6168fSJeff Roberson #include <sys/param.h> 4735e6168fSJeff Roberson #include <sys/systm.h> 482c3490b1SMarcel Moolenaar #include <sys/kdb.h> 4935e6168fSJeff Roberson #include <sys/kernel.h> 5035e6168fSJeff Roberson #include <sys/ktr.h> 51c149e542SAttilio Rao #include <sys/limits.h> 5235e6168fSJeff Roberson #include <sys/lock.h> 5335e6168fSJeff Roberson #include <sys/mutex.h> 5435e6168fSJeff Roberson #include <sys/proc.h> 55245f3abfSJeff Roberson #include <sys/resource.h> 569bacd788SJeff Roberson #include <sys/resourcevar.h> 5735e6168fSJeff Roberson #include <sys/sched.h> 58b3e9e682SRyan Stone #include <sys/sdt.h> 5935e6168fSJeff Roberson #include <sys/smp.h> 6035e6168fSJeff Roberson #include <sys/sx.h> 6135e6168fSJeff Roberson #include <sys/sysctl.h> 6235e6168fSJeff Roberson #include <sys/sysproto.h> 63f5c157d9SJohn Baldwin #include <sys/turnstile.h> 643db720fdSDavid Xu #include <sys/umtx.h> 6535e6168fSJeff Roberson #include <sys/vmmeter.h> 6662fa74d9SJeff Roberson #include <sys/cpuset.h> 6707095abfSIvan Voras #include <sys/sbuf.h> 6835e6168fSJeff Roberson 69ebccf1e3SJoseph Koshy #ifdef HWPMC_HOOKS 70ebccf1e3SJoseph Koshy #include <sys/pmckern.h> 71ebccf1e3SJoseph Koshy #endif 72ebccf1e3SJoseph Koshy 736f5f25e5SJohn Birrell #ifdef KDTRACE_HOOKS 746f5f25e5SJohn Birrell #include <sys/dtrace_bsd.h> 7561322a0aSAlexander Motin int __read_mostly dtrace_vtime_active; 766f5f25e5SJohn Birrell dtrace_vtime_switch_func_t dtrace_vtime_switch_func; 776f5f25e5SJohn Birrell #endif 786f5f25e5SJohn Birrell 7935e6168fSJeff Roberson #include <machine/cpu.h> 8022bf7d9aSJeff Roberson #include <machine/smp.h> 8135e6168fSJeff Roberson 82ae7a6b38SJeff Roberson #define KTR_ULE 0 8314618990SJeff Roberson 840d2cf837SJeff Roberson #define TS_NAME_LEN (MAXCOMLEN + sizeof(" td ") + sizeof(__XSTRING(UINT_MAX))) 850d2cf837SJeff Roberson #define TDQ_NAME_LEN (sizeof("sched lock ") + sizeof(__XSTRING(MAXCPU))) 866338c579SAttilio Rao #define TDQ_LOADNAME_LEN (sizeof("CPU ") + sizeof(__XSTRING(MAXCPU)) - 1 + sizeof(" load")) 878f51ad55SJeff Roberson 886b2f763fSJeff Roberson /* 89ae7a6b38SJeff Roberson * Thread scheduler specific section. All fields are protected 90ae7a6b38SJeff Roberson * by the thread lock. 91ed062c8dSJulian Elischer */ 92ad1e7d28SJulian Elischer struct td_sched { 93ae7a6b38SJeff Roberson struct runq *ts_runq; /* Run-queue we're queued on. */ 94ae7a6b38SJeff Roberson short ts_flags; /* TSF_* flags. */ 95e77f9fedSAdrian Chadd int ts_cpu; /* CPU that we have affinity for. */ 9673daf66fSJeff Roberson int ts_rltick; /* Real last tick, for affinity. */ 97ae7a6b38SJeff Roberson int ts_slice; /* Ticks of slice remaining. */ 98ae7a6b38SJeff Roberson u_int ts_slptime; /* Number of ticks we vol. slept */ 99ae7a6b38SJeff Roberson u_int ts_runtime; /* Number of ticks we were running */ 100ad1e7d28SJulian Elischer int ts_ltick; /* Last tick that we were running on */ 101ad1e7d28SJulian Elischer int ts_ftick; /* First tick that we were running on */ 102ad1e7d28SJulian Elischer int ts_ticks; /* Tick count */ 1038f51ad55SJeff Roberson #ifdef KTR 1048f51ad55SJeff Roberson char ts_name[TS_NAME_LEN]; 1058f51ad55SJeff Roberson #endif 106ed062c8dSJulian Elischer }; 107ad1e7d28SJulian Elischer /* flags kept in ts_flags */ 1087b8bfa0dSJeff Roberson #define TSF_BOUND 0x0001 /* Thread can not migrate. */ 1097b8bfa0dSJeff Roberson #define TSF_XFERABLE 0x0002 /* Thread was added as transferable. */ 11035e6168fSJeff Roberson 11162fa74d9SJeff Roberson #define THREAD_CAN_MIGRATE(td) ((td)->td_pinned == 0) 11262fa74d9SJeff Roberson #define THREAD_CAN_SCHED(td, cpu) \ 11362fa74d9SJeff Roberson CPU_ISSET((cpu), &(td)->td_cpuset->cs_mask) 11462fa74d9SJeff Roberson 11593ccd6bfSKonstantin Belousov _Static_assert(sizeof(struct thread) + sizeof(struct td_sched) <= 11693ccd6bfSKonstantin Belousov sizeof(struct thread0_storage), 11793ccd6bfSKonstantin Belousov "increase struct thread0_storage.t0st_sched size"); 11893ccd6bfSKonstantin Belousov 11935e6168fSJeff Roberson /* 12012d56c0fSJohn Baldwin * Priority ranges used for interactive and non-interactive timeshare 1212dc29adbSJohn Baldwin * threads. The timeshare priorities are split up into four ranges. 1222dc29adbSJohn Baldwin * The first range handles interactive threads. The last three ranges 1232dc29adbSJohn Baldwin * (NHALF, x, and NHALF) handle non-interactive threads with the outer 1242dc29adbSJohn Baldwin * ranges supporting nice values. 12512d56c0fSJohn Baldwin */ 1262dc29adbSJohn Baldwin #define PRI_TIMESHARE_RANGE (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE + 1) 1272dc29adbSJohn Baldwin #define PRI_INTERACT_RANGE ((PRI_TIMESHARE_RANGE - SCHED_PRI_NRESV) / 2) 12816705791SAndriy Gapon #define PRI_BATCH_RANGE (PRI_TIMESHARE_RANGE - PRI_INTERACT_RANGE) 1292dc29adbSJohn Baldwin 1302dc29adbSJohn Baldwin #define PRI_MIN_INTERACT PRI_MIN_TIMESHARE 1312dc29adbSJohn Baldwin #define PRI_MAX_INTERACT (PRI_MIN_TIMESHARE + PRI_INTERACT_RANGE - 1) 1322dc29adbSJohn Baldwin #define PRI_MIN_BATCH (PRI_MIN_TIMESHARE + PRI_INTERACT_RANGE) 13312d56c0fSJohn Baldwin #define PRI_MAX_BATCH PRI_MAX_TIMESHARE 13412d56c0fSJohn Baldwin 13512d56c0fSJohn Baldwin /* 136e7d50326SJeff Roberson * Cpu percentage computation macros and defines. 137e1f89c22SJeff Roberson * 138e7d50326SJeff Roberson * SCHED_TICK_SECS: Number of seconds to average the cpu usage across. 139e7d50326SJeff Roberson * SCHED_TICK_TARG: Number of hz ticks to average the cpu usage across. 1408ab80cf0SJeff Roberson * SCHED_TICK_MAX: Maximum number of ticks before scaling back. 141e7d50326SJeff Roberson * SCHED_TICK_SHIFT: Shift factor to avoid rounding away results. 142e7d50326SJeff Roberson * SCHED_TICK_HZ: Compute the number of hz ticks for a given ticks count. 143e7d50326SJeff Roberson * SCHED_TICK_TOTAL: Gives the amount of time we've been recording ticks. 14435e6168fSJeff Roberson */ 145e7d50326SJeff Roberson #define SCHED_TICK_SECS 10 146e7d50326SJeff Roberson #define SCHED_TICK_TARG (hz * SCHED_TICK_SECS) 1478ab80cf0SJeff Roberson #define SCHED_TICK_MAX (SCHED_TICK_TARG + hz) 148e7d50326SJeff Roberson #define SCHED_TICK_SHIFT 10 149e7d50326SJeff Roberson #define SCHED_TICK_HZ(ts) ((ts)->ts_ticks >> SCHED_TICK_SHIFT) 150eddb4efaSJeff Roberson #define SCHED_TICK_TOTAL(ts) (max((ts)->ts_ltick - (ts)->ts_ftick, hz)) 15135e6168fSJeff Roberson 15235e6168fSJeff Roberson /* 153e7d50326SJeff Roberson * These macros determine priorities for non-interactive threads. They are 154e7d50326SJeff Roberson * assigned a priority based on their recent cpu utilization as expressed 155e7d50326SJeff Roberson * by the ratio of ticks to the tick total. NHALF priorities at the start 156e7d50326SJeff Roberson * and end of the MIN to MAX timeshare range are only reachable with negative 157e7d50326SJeff Roberson * or positive nice respectively. 158e7d50326SJeff Roberson * 159e7d50326SJeff Roberson * PRI_RANGE: Priority range for utilization dependent priorities. 160e7d50326SJeff Roberson * PRI_NRESV: Number of nice values. 161e7d50326SJeff Roberson * PRI_TICKS: Compute a priority in PRI_RANGE from the ticks count and total. 162e7d50326SJeff Roberson * PRI_NICE: Determines the part of the priority inherited from nice. 163e7d50326SJeff Roberson */ 164e7d50326SJeff Roberson #define SCHED_PRI_NRESV (PRIO_MAX - PRIO_MIN) 165e7d50326SJeff Roberson #define SCHED_PRI_NHALF (SCHED_PRI_NRESV / 2) 16612d56c0fSJohn Baldwin #define SCHED_PRI_MIN (PRI_MIN_BATCH + SCHED_PRI_NHALF) 16712d56c0fSJohn Baldwin #define SCHED_PRI_MAX (PRI_MAX_BATCH - SCHED_PRI_NHALF) 16878920008SJohn Baldwin #define SCHED_PRI_RANGE (SCHED_PRI_MAX - SCHED_PRI_MIN + 1) 169e7d50326SJeff Roberson #define SCHED_PRI_TICKS(ts) \ 170e7d50326SJeff Roberson (SCHED_TICK_HZ((ts)) / \ 1711e516cf5SJeff Roberson (roundup(SCHED_TICK_TOTAL((ts)), SCHED_PRI_RANGE) / SCHED_PRI_RANGE)) 172e7d50326SJeff Roberson #define SCHED_PRI_NICE(nice) (nice) 173e7d50326SJeff Roberson 174e7d50326SJeff Roberson /* 175e7d50326SJeff Roberson * These determine the interactivity of a process. Interactivity differs from 176e7d50326SJeff Roberson * cpu utilization in that it expresses the voluntary time slept vs time ran 177e7d50326SJeff Roberson * while cpu utilization includes all time not running. This more accurately 178e7d50326SJeff Roberson * models the intent of the thread. 17935e6168fSJeff Roberson * 180407b0157SJeff Roberson * SLP_RUN_MAX: Maximum amount of sleep time + run time we'll accumulate 181407b0157SJeff Roberson * before throttling back. 182d322132cSJeff Roberson * SLP_RUN_FORK: Maximum slp+run time to inherit at fork time. 183210491d3SJeff Roberson * INTERACT_MAX: Maximum interactivity value. Smaller is better. 1849f518f20SAttilio Rao * INTERACT_THRESH: Threshold for placement on the current runq. 18535e6168fSJeff Roberson */ 186e7d50326SJeff Roberson #define SCHED_SLP_RUN_MAX ((hz * 5) << SCHED_TICK_SHIFT) 187e7d50326SJeff Roberson #define SCHED_SLP_RUN_FORK ((hz / 2) << SCHED_TICK_SHIFT) 188210491d3SJeff Roberson #define SCHED_INTERACT_MAX (100) 189210491d3SJeff Roberson #define SCHED_INTERACT_HALF (SCHED_INTERACT_MAX / 2) 1904c9612c6SJeff Roberson #define SCHED_INTERACT_THRESH (30) 191e1f89c22SJeff Roberson 1925e5c3873SJeff Roberson /* 1935e5c3873SJeff Roberson * These parameters determine the slice behavior for batch work. 1945e5c3873SJeff Roberson */ 1955e5c3873SJeff Roberson #define SCHED_SLICE_DEFAULT_DIVISOR 10 /* ~94 ms, 12 stathz ticks. */ 1965e5c3873SJeff Roberson #define SCHED_SLICE_MIN_DIVISOR 6 /* DEFAULT/MIN = ~16 ms. */ 1975e5c3873SJeff Roberson 1983d7f4117SAlexander Motin /* Flags kept in td_flags. */ 1993d7f4117SAlexander Motin #define TDF_SLICEEND TDF_SCHED2 /* Thread time slice is over. */ 2003d7f4117SAlexander Motin 20135e6168fSJeff Roberson /* 202e7d50326SJeff Roberson * tickincr: Converts a stathz tick into a hz domain scaled by 203e7d50326SJeff Roberson * the shift factor. Without the shift the error rate 204e7d50326SJeff Roberson * due to rounding would be unacceptably high. 205e7d50326SJeff Roberson * realstathz: stathz is sometimes 0 and run off of hz. 206e7d50326SJeff Roberson * sched_slice: Runtime of each thread before rescheduling. 207ae7a6b38SJeff Roberson * preempt_thresh: Priority threshold for preemption and remote IPIs. 20835e6168fSJeff Roberson */ 20961322a0aSAlexander Motin static int __read_mostly sched_interact = SCHED_INTERACT_THRESH; 21061322a0aSAlexander Motin static int __read_mostly tickincr = 8 << SCHED_TICK_SHIFT; 21161322a0aSAlexander Motin static int __read_mostly realstathz = 127; /* reset during boot. */ 21261322a0aSAlexander Motin static int __read_mostly sched_slice = 10; /* reset during boot. */ 21361322a0aSAlexander Motin static int __read_mostly sched_slice_min = 1; /* reset during boot. */ 21402e2d6b4SJeff Roberson #ifdef PREEMPTION 21502e2d6b4SJeff Roberson #ifdef FULL_PREEMPTION 21661322a0aSAlexander Motin static int __read_mostly preempt_thresh = PRI_MAX_IDLE; 21702e2d6b4SJeff Roberson #else 21861322a0aSAlexander Motin static int __read_mostly preempt_thresh = PRI_MIN_KERN; 21902e2d6b4SJeff Roberson #endif 22002e2d6b4SJeff Roberson #else 22161322a0aSAlexander Motin static int __read_mostly preempt_thresh = 0; 22202e2d6b4SJeff Roberson #endif 22361322a0aSAlexander Motin static int __read_mostly static_boost = PRI_MIN_BATCH; 22461322a0aSAlexander Motin static int __read_mostly sched_idlespins = 10000; 22561322a0aSAlexander Motin static int __read_mostly sched_idlespinthresh = -1; 226ae7a6b38SJeff Roberson 22735e6168fSJeff Roberson /* 228ae7a6b38SJeff Roberson * tdq - per processor runqs and statistics. All fields are protected by the 229ae7a6b38SJeff Roberson * tdq_lock. The load and lowpri may be accessed without to avoid excess 230ae7a6b38SJeff Roberson * locking in sched_pickcpu(); 23135e6168fSJeff Roberson */ 232ad1e7d28SJulian Elischer struct tdq { 23339f819e2SJim Harris /* 23439f819e2SJim Harris * Ordered to improve efficiency of cpu_search() and switch(). 23539f819e2SJim Harris * tdq_lock is padded to avoid false sharing with tdq_load and 23639f819e2SJim Harris * tdq_cpu_idle. 23739f819e2SJim Harris */ 2384ceaf45dSAttilio Rao struct mtx_padalign tdq_lock; /* run queue lock. */ 23973daf66fSJeff Roberson struct cpu_group *tdq_cg; /* Pointer to cpu topology. */ 2401690c6c1SJeff Roberson volatile int tdq_load; /* Aggregate load. */ 2419f9ad565SAlexander Motin volatile int tdq_cpu_idle; /* cpu_idle() is active. */ 24273daf66fSJeff Roberson int tdq_sysload; /* For loadavg, !ITHD load. */ 24397e9382dSDon Lewis volatile int tdq_transferable; /* Transferable thread count. */ 24497e9382dSDon Lewis volatile short tdq_switchcnt; /* Switches this tick. */ 24597e9382dSDon Lewis volatile short tdq_oldswitchcnt; /* Switches last tick. */ 24673daf66fSJeff Roberson u_char tdq_lowpri; /* Lowest priority thread. */ 2477789ab32SMark Johnston u_char tdq_owepreempt; /* Remote preemption pending. */ 24873daf66fSJeff Roberson u_char tdq_idx; /* Current insert index. */ 24973daf66fSJeff Roberson u_char tdq_ridx; /* Current removal index. */ 250018ff686SJeff Roberson int tdq_id; /* cpuid. */ 251e7d50326SJeff Roberson struct runq tdq_realtime; /* real-time run queue. */ 252ae7a6b38SJeff Roberson struct runq tdq_timeshare; /* timeshare run queue. */ 253ae7a6b38SJeff Roberson struct runq tdq_idle; /* Queue of IDLE threads. */ 2548f51ad55SJeff Roberson char tdq_name[TDQ_NAME_LEN]; 2558f51ad55SJeff Roberson #ifdef KTR 2568f51ad55SJeff Roberson char tdq_loadname[TDQ_LOADNAME_LEN]; 2578f51ad55SJeff Roberson #endif 258ae7a6b38SJeff Roberson } __aligned(64); 25935e6168fSJeff Roberson 2601690c6c1SJeff Roberson /* Idle thread states and config. */ 2611690c6c1SJeff Roberson #define TDQ_RUNNING 1 2621690c6c1SJeff Roberson #define TDQ_IDLE 2 2637b8bfa0dSJeff Roberson 26480f86c9fSJeff Roberson #ifdef SMP 26561322a0aSAlexander Motin struct cpu_group __read_mostly *cpu_top; /* CPU topology */ 2667b8bfa0dSJeff Roberson 26762fa74d9SJeff Roberson #define SCHED_AFFINITY_DEFAULT (max(1, hz / 1000)) 26862fa74d9SJeff Roberson #define SCHED_AFFINITY(ts, t) ((ts)->ts_rltick > ticks - ((t) * affinity)) 2697b8bfa0dSJeff Roberson 2707b8bfa0dSJeff Roberson /* 2717b8bfa0dSJeff Roberson * Run-time tunables. 2727b8bfa0dSJeff Roberson */ 27328994a58SJeff Roberson static int rebalance = 1; 2747fcf154aSJeff Roberson static int balance_interval = 128; /* Default set in sched_initticks(). */ 27561322a0aSAlexander Motin static int __read_mostly affinity; 27661322a0aSAlexander Motin static int __read_mostly steal_idle = 1; 27761322a0aSAlexander Motin static int __read_mostly steal_thresh = 2; 27861322a0aSAlexander Motin static int __read_mostly always_steal = 0; 27961322a0aSAlexander Motin static int __read_mostly trysteal_limit = 2; 28080f86c9fSJeff Roberson 28135e6168fSJeff Roberson /* 282d2ad694cSJeff Roberson * One thread queue per processor. 28335e6168fSJeff Roberson */ 28461322a0aSAlexander Motin static struct tdq __read_mostly *balance_tdq; 2857fcf154aSJeff Roberson static int balance_ticks; 286018ff686SJeff Roberson DPCPU_DEFINE_STATIC(struct tdq, tdq); 2872bf95012SAndrew Turner DPCPU_DEFINE_STATIC(uint32_t, randomval); 288dc03363dSJeff Roberson 289018ff686SJeff Roberson #define TDQ_SELF() ((struct tdq *)PCPU_GET(sched)) 290018ff686SJeff Roberson #define TDQ_CPU(x) (DPCPU_ID_PTR((x), tdq)) 291018ff686SJeff Roberson #define TDQ_ID(x) ((x)->tdq_id) 29280f86c9fSJeff Roberson #else /* !SMP */ 293ad1e7d28SJulian Elischer static struct tdq tdq_cpu; 294dc03363dSJeff Roberson 29536b36916SJeff Roberson #define TDQ_ID(x) (0) 296ad1e7d28SJulian Elischer #define TDQ_SELF() (&tdq_cpu) 297ad1e7d28SJulian Elischer #define TDQ_CPU(x) (&tdq_cpu) 2980a016a05SJeff Roberson #endif 29935e6168fSJeff Roberson 300ae7a6b38SJeff Roberson #define TDQ_LOCK_ASSERT(t, type) mtx_assert(TDQ_LOCKPTR((t)), (type)) 301ae7a6b38SJeff Roberson #define TDQ_LOCK(t) mtx_lock_spin(TDQ_LOCKPTR((t))) 302ae7a6b38SJeff Roberson #define TDQ_LOCK_FLAGS(t, f) mtx_lock_spin_flags(TDQ_LOCKPTR((t)), (f)) 303ae7a6b38SJeff Roberson #define TDQ_UNLOCK(t) mtx_unlock_spin(TDQ_LOCKPTR((t))) 3044ceaf45dSAttilio Rao #define TDQ_LOCKPTR(t) ((struct mtx *)(&(t)->tdq_lock)) 305ae7a6b38SJeff Roberson 3068460a577SJohn Birrell static void sched_priority(struct thread *); 30721381d1bSJeff Roberson static void sched_thread_priority(struct thread *, u_char); 3088460a577SJohn Birrell static int sched_interact_score(struct thread *); 3098460a577SJohn Birrell static void sched_interact_update(struct thread *); 3108460a577SJohn Birrell static void sched_interact_fork(struct thread *); 3117295465eSAlexander Motin static void sched_pctcpu_update(struct td_sched *, int); 31235e6168fSJeff Roberson 3135d7ef00cSJeff Roberson /* Operations on per processor queues */ 3149727e637SJeff Roberson static struct thread *tdq_choose(struct tdq *); 315018ff686SJeff Roberson static void tdq_setup(struct tdq *, int i); 3169727e637SJeff Roberson static void tdq_load_add(struct tdq *, struct thread *); 3179727e637SJeff Roberson static void tdq_load_rem(struct tdq *, struct thread *); 3189727e637SJeff Roberson static __inline void tdq_runq_add(struct tdq *, struct thread *, int); 3199727e637SJeff Roberson static __inline void tdq_runq_rem(struct tdq *, struct thread *); 320ff256d9cSJeff Roberson static inline int sched_shouldpreempt(int, int, int); 321ad1e7d28SJulian Elischer void tdq_print(int cpu); 322e7d50326SJeff Roberson static void runq_print(struct runq *rq); 323ae7a6b38SJeff Roberson static void tdq_add(struct tdq *, struct thread *, int); 3245d7ef00cSJeff Roberson #ifdef SMP 32597e9382dSDon Lewis static struct thread *tdq_move(struct tdq *, struct tdq *); 326ad1e7d28SJulian Elischer static int tdq_idled(struct tdq *); 32727ee18adSRyan Stone static void tdq_notify(struct tdq *, struct thread *); 3289727e637SJeff Roberson static struct thread *tdq_steal(struct tdq *, int); 3299727e637SJeff Roberson static struct thread *runq_steal(struct runq *, int); 3309727e637SJeff Roberson static int sched_pickcpu(struct thread *, int); 3317fcf154aSJeff Roberson static void sched_balance(void); 33262fa74d9SJeff Roberson static int sched_balance_pair(struct tdq *, struct tdq *); 3339727e637SJeff Roberson static inline struct tdq *sched_setcpu(struct thread *, int, int); 334ae7a6b38SJeff Roberson static inline void thread_unblock_switch(struct thread *, struct mtx *); 335c47f202bSJeff Roberson static struct mtx *sched_switch_migrate(struct tdq *, struct thread *, int); 33607095abfSIvan Voras static int sysctl_kern_sched_topology_spec(SYSCTL_HANDLER_ARGS); 33707095abfSIvan Voras static int sysctl_kern_sched_topology_spec_internal(struct sbuf *sb, 33807095abfSIvan Voras struct cpu_group *cg, int indent); 3395d7ef00cSJeff Roberson #endif 3405d7ef00cSJeff Roberson 341e7d50326SJeff Roberson static void sched_setup(void *dummy); 342237fdd78SRobert Watson SYSINIT(sched_setup, SI_SUB_RUN_QUEUE, SI_ORDER_FIRST, sched_setup, NULL); 343e7d50326SJeff Roberson 344e7d50326SJeff Roberson static void sched_initticks(void *dummy); 345237fdd78SRobert Watson SYSINIT(sched_initticks, SI_SUB_CLOCKS, SI_ORDER_THIRD, sched_initticks, 346237fdd78SRobert Watson NULL); 347e7d50326SJeff Roberson 348b3e9e682SRyan Stone SDT_PROVIDER_DEFINE(sched); 349b3e9e682SRyan Stone 350d9fae5abSAndriy Gapon SDT_PROBE_DEFINE3(sched, , , change__pri, "struct thread *", 351b3e9e682SRyan Stone "struct proc *", "uint8_t"); 352d9fae5abSAndriy Gapon SDT_PROBE_DEFINE3(sched, , , dequeue, "struct thread *", 353b3e9e682SRyan Stone "struct proc *", "void *"); 354d9fae5abSAndriy Gapon SDT_PROBE_DEFINE4(sched, , , enqueue, "struct thread *", 355b3e9e682SRyan Stone "struct proc *", "void *", "int"); 356d9fae5abSAndriy Gapon SDT_PROBE_DEFINE4(sched, , , lend__pri, "struct thread *", 357b3e9e682SRyan Stone "struct proc *", "uint8_t", "struct thread *"); 358d9fae5abSAndriy Gapon SDT_PROBE_DEFINE2(sched, , , load__change, "int", "int"); 359d9fae5abSAndriy Gapon SDT_PROBE_DEFINE2(sched, , , off__cpu, "struct thread *", 360b3e9e682SRyan Stone "struct proc *"); 361d9fae5abSAndriy Gapon SDT_PROBE_DEFINE(sched, , , on__cpu); 362d9fae5abSAndriy Gapon SDT_PROBE_DEFINE(sched, , , remain__cpu); 363d9fae5abSAndriy Gapon SDT_PROBE_DEFINE2(sched, , , surrender, "struct thread *", 364b3e9e682SRyan Stone "struct proc *"); 365b3e9e682SRyan Stone 3660567b6ccSWarner Losh /* 367ae7a6b38SJeff Roberson * Print the threads waiting on a run-queue. 368ae7a6b38SJeff Roberson */ 369e7d50326SJeff Roberson static void 370e7d50326SJeff Roberson runq_print(struct runq *rq) 371e7d50326SJeff Roberson { 372e7d50326SJeff Roberson struct rqhead *rqh; 3739727e637SJeff Roberson struct thread *td; 374e7d50326SJeff Roberson int pri; 375e7d50326SJeff Roberson int j; 376e7d50326SJeff Roberson int i; 377e7d50326SJeff Roberson 378e7d50326SJeff Roberson for (i = 0; i < RQB_LEN; i++) { 379e7d50326SJeff Roberson printf("\t\trunq bits %d 0x%zx\n", 380e7d50326SJeff Roberson i, rq->rq_status.rqb_bits[i]); 381e7d50326SJeff Roberson for (j = 0; j < RQB_BPW; j++) 382e7d50326SJeff Roberson if (rq->rq_status.rqb_bits[i] & (1ul << j)) { 383e7d50326SJeff Roberson pri = j + (i << RQB_L2BPW); 384e7d50326SJeff Roberson rqh = &rq->rq_queues[pri]; 3859727e637SJeff Roberson TAILQ_FOREACH(td, rqh, td_runq) { 386e7d50326SJeff Roberson printf("\t\t\ttd %p(%s) priority %d rqindex %d pri %d\n", 3879727e637SJeff Roberson td, td->td_name, td->td_priority, 3889727e637SJeff Roberson td->td_rqindex, pri); 389e7d50326SJeff Roberson } 390e7d50326SJeff Roberson } 391e7d50326SJeff Roberson } 392e7d50326SJeff Roberson } 393e7d50326SJeff Roberson 394ae7a6b38SJeff Roberson /* 395ae7a6b38SJeff Roberson * Print the status of a per-cpu thread queue. Should be a ddb show cmd. 396ae7a6b38SJeff Roberson */ 39715dc847eSJeff Roberson void 398ad1e7d28SJulian Elischer tdq_print(int cpu) 39915dc847eSJeff Roberson { 400ad1e7d28SJulian Elischer struct tdq *tdq; 40115dc847eSJeff Roberson 402ad1e7d28SJulian Elischer tdq = TDQ_CPU(cpu); 40315dc847eSJeff Roberson 404c47f202bSJeff Roberson printf("tdq %d:\n", TDQ_ID(tdq)); 40562fa74d9SJeff Roberson printf("\tlock %p\n", TDQ_LOCKPTR(tdq)); 40662fa74d9SJeff Roberson printf("\tLock name: %s\n", tdq->tdq_name); 407d2ad694cSJeff Roberson printf("\tload: %d\n", tdq->tdq_load); 4081690c6c1SJeff Roberson printf("\tswitch cnt: %d\n", tdq->tdq_switchcnt); 4091690c6c1SJeff Roberson printf("\told switch cnt: %d\n", tdq->tdq_oldswitchcnt); 410e7d50326SJeff Roberson printf("\ttimeshare idx: %d\n", tdq->tdq_idx); 4113f872f85SJeff Roberson printf("\ttimeshare ridx: %d\n", tdq->tdq_ridx); 4121690c6c1SJeff Roberson printf("\tload transferable: %d\n", tdq->tdq_transferable); 4131690c6c1SJeff Roberson printf("\tlowest priority: %d\n", tdq->tdq_lowpri); 414e7d50326SJeff Roberson printf("\trealtime runq:\n"); 415e7d50326SJeff Roberson runq_print(&tdq->tdq_realtime); 416e7d50326SJeff Roberson printf("\ttimeshare runq:\n"); 417e7d50326SJeff Roberson runq_print(&tdq->tdq_timeshare); 418e7d50326SJeff Roberson printf("\tidle runq:\n"); 419e7d50326SJeff Roberson runq_print(&tdq->tdq_idle); 42015dc847eSJeff Roberson } 42115dc847eSJeff Roberson 422ff256d9cSJeff Roberson static inline int 423ff256d9cSJeff Roberson sched_shouldpreempt(int pri, int cpri, int remote) 424ff256d9cSJeff Roberson { 425ff256d9cSJeff Roberson /* 426ff256d9cSJeff Roberson * If the new priority is not better than the current priority there is 427ff256d9cSJeff Roberson * nothing to do. 428ff256d9cSJeff Roberson */ 429ff256d9cSJeff Roberson if (pri >= cpri) 430ff256d9cSJeff Roberson return (0); 431ff256d9cSJeff Roberson /* 432ff256d9cSJeff Roberson * Always preempt idle. 433ff256d9cSJeff Roberson */ 434ff256d9cSJeff Roberson if (cpri >= PRI_MIN_IDLE) 435ff256d9cSJeff Roberson return (1); 436ff256d9cSJeff Roberson /* 437ff256d9cSJeff Roberson * If preemption is disabled don't preempt others. 438ff256d9cSJeff Roberson */ 439ff256d9cSJeff Roberson if (preempt_thresh == 0) 440ff256d9cSJeff Roberson return (0); 441ff256d9cSJeff Roberson /* 442ff256d9cSJeff Roberson * Preempt if we exceed the threshold. 443ff256d9cSJeff Roberson */ 444ff256d9cSJeff Roberson if (pri <= preempt_thresh) 445ff256d9cSJeff Roberson return (1); 446ff256d9cSJeff Roberson /* 44712d56c0fSJohn Baldwin * If we're interactive or better and there is non-interactive 44812d56c0fSJohn Baldwin * or worse running preempt only remote processors. 449ff256d9cSJeff Roberson */ 45012d56c0fSJohn Baldwin if (remote && pri <= PRI_MAX_INTERACT && cpri > PRI_MAX_INTERACT) 451ff256d9cSJeff Roberson return (1); 452ff256d9cSJeff Roberson return (0); 453ff256d9cSJeff Roberson } 454ff256d9cSJeff Roberson 455ae7a6b38SJeff Roberson /* 456ae7a6b38SJeff Roberson * Add a thread to the actual run-queue. Keeps transferable counts up to 457ae7a6b38SJeff Roberson * date with what is actually on the run-queue. Selects the correct 458ae7a6b38SJeff Roberson * queue position for timeshare threads. 459ae7a6b38SJeff Roberson */ 460155b9987SJeff Roberson static __inline void 4619727e637SJeff Roberson tdq_runq_add(struct tdq *tdq, struct thread *td, int flags) 462155b9987SJeff Roberson { 4639727e637SJeff Roberson struct td_sched *ts; 464c143ac21SJeff Roberson u_char pri; 465c143ac21SJeff Roberson 466ae7a6b38SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED); 467*61a74c5cSJeff Roberson THREAD_LOCK_BLOCKED_ASSERT(td, MA_OWNED); 46873daf66fSJeff Roberson 4699727e637SJeff Roberson pri = td->td_priority; 47093ccd6bfSKonstantin Belousov ts = td_get_sched(td); 4719727e637SJeff Roberson TD_SET_RUNQ(td); 4729727e637SJeff Roberson if (THREAD_CAN_MIGRATE(td)) { 473d2ad694cSJeff Roberson tdq->tdq_transferable++; 474ad1e7d28SJulian Elischer ts->ts_flags |= TSF_XFERABLE; 47580f86c9fSJeff Roberson } 47612d56c0fSJohn Baldwin if (pri < PRI_MIN_BATCH) { 477c143ac21SJeff Roberson ts->ts_runq = &tdq->tdq_realtime; 47812d56c0fSJohn Baldwin } else if (pri <= PRI_MAX_BATCH) { 479c143ac21SJeff Roberson ts->ts_runq = &tdq->tdq_timeshare; 48012d56c0fSJohn Baldwin KASSERT(pri <= PRI_MAX_BATCH && pri >= PRI_MIN_BATCH, 481e7d50326SJeff Roberson ("Invalid priority %d on timeshare runq", pri)); 482e7d50326SJeff Roberson /* 483e7d50326SJeff Roberson * This queue contains only priorities between MIN and MAX 484e7d50326SJeff Roberson * realtime. Use the whole queue to represent these values. 485e7d50326SJeff Roberson */ 486c47f202bSJeff Roberson if ((flags & (SRQ_BORROWING|SRQ_PREEMPTED)) == 0) { 48716705791SAndriy Gapon pri = RQ_NQS * (pri - PRI_MIN_BATCH) / PRI_BATCH_RANGE; 488e7d50326SJeff Roberson pri = (pri + tdq->tdq_idx) % RQ_NQS; 4893f872f85SJeff Roberson /* 4903f872f85SJeff Roberson * This effectively shortens the queue by one so we 4913f872f85SJeff Roberson * can have a one slot difference between idx and 4923f872f85SJeff Roberson * ridx while we wait for threads to drain. 4933f872f85SJeff Roberson */ 4943f872f85SJeff Roberson if (tdq->tdq_ridx != tdq->tdq_idx && 4953f872f85SJeff Roberson pri == tdq->tdq_ridx) 4964499aff6SJeff Roberson pri = (unsigned char)(pri - 1) % RQ_NQS; 497e7d50326SJeff Roberson } else 4983f872f85SJeff Roberson pri = tdq->tdq_ridx; 4999727e637SJeff Roberson runq_add_pri(ts->ts_runq, td, pri, flags); 500c143ac21SJeff Roberson return; 501e7d50326SJeff Roberson } else 50273daf66fSJeff Roberson ts->ts_runq = &tdq->tdq_idle; 5039727e637SJeff Roberson runq_add(ts->ts_runq, td, flags); 50473daf66fSJeff Roberson } 50573daf66fSJeff Roberson 50673daf66fSJeff Roberson /* 507ae7a6b38SJeff Roberson * Remove a thread from a run-queue. This typically happens when a thread 508ae7a6b38SJeff Roberson * is selected to run. Running threads are not on the queue and the 509ae7a6b38SJeff Roberson * transferable count does not reflect them. 510ae7a6b38SJeff Roberson */ 511155b9987SJeff Roberson static __inline void 5129727e637SJeff Roberson tdq_runq_rem(struct tdq *tdq, struct thread *td) 513155b9987SJeff Roberson { 5149727e637SJeff Roberson struct td_sched *ts; 5159727e637SJeff Roberson 51693ccd6bfSKonstantin Belousov ts = td_get_sched(td); 517ae7a6b38SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED); 518*61a74c5cSJeff Roberson THREAD_LOCK_BLOCKED_ASSERT(td, MA_OWNED); 519ae7a6b38SJeff Roberson KASSERT(ts->ts_runq != NULL, 5209727e637SJeff Roberson ("tdq_runq_remove: thread %p null ts_runq", td)); 521ad1e7d28SJulian Elischer if (ts->ts_flags & TSF_XFERABLE) { 522d2ad694cSJeff Roberson tdq->tdq_transferable--; 523ad1e7d28SJulian Elischer ts->ts_flags &= ~TSF_XFERABLE; 52480f86c9fSJeff Roberson } 5253f872f85SJeff Roberson if (ts->ts_runq == &tdq->tdq_timeshare) { 5263f872f85SJeff Roberson if (tdq->tdq_idx != tdq->tdq_ridx) 5279727e637SJeff Roberson runq_remove_idx(ts->ts_runq, td, &tdq->tdq_ridx); 528e7d50326SJeff Roberson else 5299727e637SJeff Roberson runq_remove_idx(ts->ts_runq, td, NULL); 5303f872f85SJeff Roberson } else 5319727e637SJeff Roberson runq_remove(ts->ts_runq, td); 532155b9987SJeff Roberson } 533155b9987SJeff Roberson 534ae7a6b38SJeff Roberson /* 535ae7a6b38SJeff Roberson * Load is maintained for all threads RUNNING and ON_RUNQ. Add the load 536ae7a6b38SJeff Roberson * for this thread to the referenced thread queue. 537ae7a6b38SJeff Roberson */ 538a8949de2SJeff Roberson static void 5399727e637SJeff Roberson tdq_load_add(struct tdq *tdq, struct thread *td) 5405d7ef00cSJeff Roberson { 541ae7a6b38SJeff Roberson 542ae7a6b38SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED); 543*61a74c5cSJeff Roberson THREAD_LOCK_BLOCKED_ASSERT(td, MA_OWNED); 54403d17db7SJeff Roberson 545d2ad694cSJeff Roberson tdq->tdq_load++; 5461b9d701fSAttilio Rao if ((td->td_flags & TDF_NOLOAD) == 0) 547d2ad694cSJeff Roberson tdq->tdq_sysload++; 5488f51ad55SJeff Roberson KTR_COUNTER0(KTR_SCHED, "load", tdq->tdq_loadname, tdq->tdq_load); 549d9fae5abSAndriy Gapon SDT_PROBE2(sched, , , load__change, (int)TDQ_ID(tdq), tdq->tdq_load); 5505d7ef00cSJeff Roberson } 55115dc847eSJeff Roberson 552ae7a6b38SJeff Roberson /* 553ae7a6b38SJeff Roberson * Remove the load from a thread that is transitioning to a sleep state or 554ae7a6b38SJeff Roberson * exiting. 555ae7a6b38SJeff Roberson */ 556a8949de2SJeff Roberson static void 5579727e637SJeff Roberson tdq_load_rem(struct tdq *tdq, struct thread *td) 5585d7ef00cSJeff Roberson { 559ae7a6b38SJeff Roberson 560ae7a6b38SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED); 561*61a74c5cSJeff Roberson THREAD_LOCK_BLOCKED_ASSERT(td, MA_OWNED); 562ae7a6b38SJeff Roberson KASSERT(tdq->tdq_load != 0, 563c47f202bSJeff Roberson ("tdq_load_rem: Removing with 0 load on queue %d", TDQ_ID(tdq))); 56403d17db7SJeff Roberson 565d2ad694cSJeff Roberson tdq->tdq_load--; 5661b9d701fSAttilio Rao if ((td->td_flags & TDF_NOLOAD) == 0) 56703d17db7SJeff Roberson tdq->tdq_sysload--; 5688f51ad55SJeff Roberson KTR_COUNTER0(KTR_SCHED, "load", tdq->tdq_loadname, tdq->tdq_load); 569d9fae5abSAndriy Gapon SDT_PROBE2(sched, , , load__change, (int)TDQ_ID(tdq), tdq->tdq_load); 57015dc847eSJeff Roberson } 57115dc847eSJeff Roberson 572356500a3SJeff Roberson /* 5735e5c3873SJeff Roberson * Bound timeshare latency by decreasing slice size as load increases. We 5745e5c3873SJeff Roberson * consider the maximum latency as the sum of the threads waiting to run 5755e5c3873SJeff Roberson * aside from curthread and target no more than sched_slice latency but 5765e5c3873SJeff Roberson * no less than sched_slice_min runtime. 5775e5c3873SJeff Roberson */ 5785e5c3873SJeff Roberson static inline int 5795e5c3873SJeff Roberson tdq_slice(struct tdq *tdq) 5805e5c3873SJeff Roberson { 5815e5c3873SJeff Roberson int load; 5825e5c3873SJeff Roberson 5835e5c3873SJeff Roberson /* 5845e5c3873SJeff Roberson * It is safe to use sys_load here because this is called from 5855e5c3873SJeff Roberson * contexts where timeshare threads are running and so there 5865e5c3873SJeff Roberson * cannot be higher priority load in the system. 5875e5c3873SJeff Roberson */ 5885e5c3873SJeff Roberson load = tdq->tdq_sysload - 1; 5895e5c3873SJeff Roberson if (load >= SCHED_SLICE_MIN_DIVISOR) 5905e5c3873SJeff Roberson return (sched_slice_min); 5915e5c3873SJeff Roberson if (load <= 1) 5925e5c3873SJeff Roberson return (sched_slice); 5935e5c3873SJeff Roberson return (sched_slice / load); 5945e5c3873SJeff Roberson } 5955e5c3873SJeff Roberson 5965e5c3873SJeff Roberson /* 59762fa74d9SJeff Roberson * Set lowpri to its exact value by searching the run-queue and 59862fa74d9SJeff Roberson * evaluating curthread. curthread may be passed as an optimization. 599356500a3SJeff Roberson */ 60022bf7d9aSJeff Roberson static void 60162fa74d9SJeff Roberson tdq_setlowpri(struct tdq *tdq, struct thread *ctd) 60262fa74d9SJeff Roberson { 60362fa74d9SJeff Roberson struct thread *td; 60462fa74d9SJeff Roberson 60562fa74d9SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED); 60662fa74d9SJeff Roberson if (ctd == NULL) 60762fa74d9SJeff Roberson ctd = pcpu_find(TDQ_ID(tdq))->pc_curthread; 6089727e637SJeff Roberson td = tdq_choose(tdq); 6099727e637SJeff Roberson if (td == NULL || td->td_priority > ctd->td_priority) 61062fa74d9SJeff Roberson tdq->tdq_lowpri = ctd->td_priority; 61162fa74d9SJeff Roberson else 61262fa74d9SJeff Roberson tdq->tdq_lowpri = td->td_priority; 61362fa74d9SJeff Roberson } 61462fa74d9SJeff Roberson 61562fa74d9SJeff Roberson #ifdef SMP 6169129dd59SPedro F. Giffuni /* 6179129dd59SPedro F. Giffuni * We need some randomness. Implement a classic Linear Congruential 6189129dd59SPedro F. Giffuni * Generator X_{n+1}=(aX_n+c) mod m. These values are optimized for 6199129dd59SPedro F. Giffuni * m = 2^32, a = 69069 and c = 5. We only return the upper 16 bits 6209129dd59SPedro F. Giffuni * of the random state (in the low bits of our answer) to keep 6219129dd59SPedro F. Giffuni * the maximum randomness. 6229129dd59SPedro F. Giffuni */ 6239129dd59SPedro F. Giffuni static uint32_t 6249129dd59SPedro F. Giffuni sched_random(void) 6259129dd59SPedro F. Giffuni { 6269129dd59SPedro F. Giffuni uint32_t *rndptr; 6279129dd59SPedro F. Giffuni 6289129dd59SPedro F. Giffuni rndptr = DPCPU_PTR(randomval); 6299129dd59SPedro F. Giffuni *rndptr = *rndptr * 69069 + 5; 6309129dd59SPedro F. Giffuni 6319129dd59SPedro F. Giffuni return (*rndptr >> 16); 6329129dd59SPedro F. Giffuni } 6339129dd59SPedro F. Giffuni 63462fa74d9SJeff Roberson struct cpu_search { 635c76ee827SJeff Roberson cpuset_t cs_mask; 63636acfc65SAlexander Motin u_int cs_prefer; 63736acfc65SAlexander Motin int cs_pri; /* Min priority for low. */ 63836acfc65SAlexander Motin int cs_limit; /* Max load for low, min load for high. */ 63936acfc65SAlexander Motin int cs_cpu; 64036acfc65SAlexander Motin int cs_load; 64162fa74d9SJeff Roberson }; 64262fa74d9SJeff Roberson 64362fa74d9SJeff Roberson #define CPU_SEARCH_LOWEST 0x1 64462fa74d9SJeff Roberson #define CPU_SEARCH_HIGHEST 0x2 64562fa74d9SJeff Roberson #define CPU_SEARCH_BOTH (CPU_SEARCH_LOWEST|CPU_SEARCH_HIGHEST) 64662fa74d9SJeff Roberson 6472499a5ccSKonstantin Belousov static __always_inline int cpu_search(const struct cpu_group *cg, 6482499a5ccSKonstantin Belousov struct cpu_search *low, struct cpu_search *high, const int match); 6492499a5ccSKonstantin Belousov int __noinline cpu_search_lowest(const struct cpu_group *cg, 6502499a5ccSKonstantin Belousov struct cpu_search *low); 6512499a5ccSKonstantin Belousov int __noinline cpu_search_highest(const struct cpu_group *cg, 65262fa74d9SJeff Roberson struct cpu_search *high); 6532499a5ccSKonstantin Belousov int __noinline cpu_search_both(const struct cpu_group *cg, 6542499a5ccSKonstantin Belousov struct cpu_search *low, struct cpu_search *high); 65562fa74d9SJeff Roberson 65662fa74d9SJeff Roberson /* 65762fa74d9SJeff Roberson * Search the tree of cpu_groups for the lowest or highest loaded cpu 65862fa74d9SJeff Roberson * according to the match argument. This routine actually compares the 65962fa74d9SJeff Roberson * load on all paths through the tree and finds the least loaded cpu on 66062fa74d9SJeff Roberson * the least loaded path, which may differ from the least loaded cpu in 661db4fcadfSConrad Meyer * the system. This balances work among caches and buses. 66262fa74d9SJeff Roberson * 66362fa74d9SJeff Roberson * This inline is instantiated in three forms below using constants for the 66462fa74d9SJeff Roberson * match argument. It is reduced to the minimum set for each case. It is 66562fa74d9SJeff Roberson * also recursive to the depth of the tree. 66662fa74d9SJeff Roberson */ 6672499a5ccSKonstantin Belousov static __always_inline int 66836acfc65SAlexander Motin cpu_search(const struct cpu_group *cg, struct cpu_search *low, 66962fa74d9SJeff Roberson struct cpu_search *high, const int match) 67062fa74d9SJeff Roberson { 67162fa74d9SJeff Roberson struct cpu_search lgroup; 67262fa74d9SJeff Roberson struct cpu_search hgroup; 67336acfc65SAlexander Motin cpuset_t cpumask; 67462fa74d9SJeff Roberson struct cpu_group *child; 67536acfc65SAlexander Motin struct tdq *tdq; 6760567b6ccSWarner Losh int cpu, i, hload, lload, load, total, rnd; 67762fa74d9SJeff Roberson 67836acfc65SAlexander Motin total = 0; 67936acfc65SAlexander Motin cpumask = cg->cg_mask; 68062fa74d9SJeff Roberson if (match & CPU_SEARCH_LOWEST) { 68136acfc65SAlexander Motin lload = INT_MAX; 68262fa74d9SJeff Roberson lgroup = *low; 68362fa74d9SJeff Roberson } 68462fa74d9SJeff Roberson if (match & CPU_SEARCH_HIGHEST) { 68570801abeSAlexander Motin hload = INT_MIN; 68662fa74d9SJeff Roberson hgroup = *high; 68762fa74d9SJeff Roberson } 68836acfc65SAlexander Motin 68936acfc65SAlexander Motin /* Iterate through the child CPU groups and then remaining CPUs. */ 69058909b74SAlexander Motin for (i = cg->cg_children, cpu = mp_maxid; ; ) { 69170801abeSAlexander Motin if (i == 0) { 69258909b74SAlexander Motin #ifdef HAVE_INLINE_FFSL 69358909b74SAlexander Motin cpu = CPU_FFS(&cpumask) - 1; 69458909b74SAlexander Motin #else 69570801abeSAlexander Motin while (cpu >= 0 && !CPU_ISSET(cpu, &cpumask)) 69670801abeSAlexander Motin cpu--; 69758909b74SAlexander Motin #endif 69870801abeSAlexander Motin if (cpu < 0) 69936acfc65SAlexander Motin break; 70036acfc65SAlexander Motin child = NULL; 70136acfc65SAlexander Motin } else 70270801abeSAlexander Motin child = &cg->cg_child[i - 1]; 70336acfc65SAlexander Motin 70470801abeSAlexander Motin if (match & CPU_SEARCH_LOWEST) 70570801abeSAlexander Motin lgroup.cs_cpu = -1; 70670801abeSAlexander Motin if (match & CPU_SEARCH_HIGHEST) 70770801abeSAlexander Motin hgroup.cs_cpu = -1; 70836acfc65SAlexander Motin if (child) { /* Handle child CPU group. */ 7099825eadfSRyan Libby CPU_ANDNOT(&cpumask, &child->cg_mask); 71062fa74d9SJeff Roberson switch (match) { 71162fa74d9SJeff Roberson case CPU_SEARCH_LOWEST: 71262fa74d9SJeff Roberson load = cpu_search_lowest(child, &lgroup); 71362fa74d9SJeff Roberson break; 71462fa74d9SJeff Roberson case CPU_SEARCH_HIGHEST: 71562fa74d9SJeff Roberson load = cpu_search_highest(child, &hgroup); 71662fa74d9SJeff Roberson break; 71762fa74d9SJeff Roberson case CPU_SEARCH_BOTH: 71862fa74d9SJeff Roberson load = cpu_search_both(child, &lgroup, &hgroup); 71962fa74d9SJeff Roberson break; 72062fa74d9SJeff Roberson } 72136acfc65SAlexander Motin } else { /* Handle child CPU. */ 72258909b74SAlexander Motin CPU_CLR(cpu, &cpumask); 72336acfc65SAlexander Motin tdq = TDQ_CPU(cpu); 72436acfc65SAlexander Motin load = tdq->tdq_load * 256; 725b250ad34SWarner Losh rnd = sched_random() % 32; 72636acfc65SAlexander Motin if (match & CPU_SEARCH_LOWEST) { 72736acfc65SAlexander Motin if (cpu == low->cs_prefer) 72836acfc65SAlexander Motin load -= 64; 72936acfc65SAlexander Motin /* If that CPU is allowed and get data. */ 73070801abeSAlexander Motin if (tdq->tdq_lowpri > lgroup.cs_pri && 73170801abeSAlexander Motin tdq->tdq_load <= lgroup.cs_limit && 73270801abeSAlexander Motin CPU_ISSET(cpu, &lgroup.cs_mask)) { 73336acfc65SAlexander Motin lgroup.cs_cpu = cpu; 73436acfc65SAlexander Motin lgroup.cs_load = load - rnd; 73536acfc65SAlexander Motin } 73662fa74d9SJeff Roberson } 73762fa74d9SJeff Roberson if (match & CPU_SEARCH_HIGHEST) 73870801abeSAlexander Motin if (tdq->tdq_load >= hgroup.cs_limit && 73970801abeSAlexander Motin tdq->tdq_transferable && 74070801abeSAlexander Motin CPU_ISSET(cpu, &hgroup.cs_mask)) { 74136acfc65SAlexander Motin hgroup.cs_cpu = cpu; 74236acfc65SAlexander Motin hgroup.cs_load = load - rnd; 74362fa74d9SJeff Roberson } 74462fa74d9SJeff Roberson } 74536acfc65SAlexander Motin total += load; 74662fa74d9SJeff Roberson 74736acfc65SAlexander Motin /* We have info about child item. Compare it. */ 74836acfc65SAlexander Motin if (match & CPU_SEARCH_LOWEST) { 74970801abeSAlexander Motin if (lgroup.cs_cpu >= 0 && 7506022f0bcSAlexander Motin (load < lload || 7516022f0bcSAlexander Motin (load == lload && lgroup.cs_load < low->cs_load))) { 75236acfc65SAlexander Motin lload = load; 75336acfc65SAlexander Motin low->cs_cpu = lgroup.cs_cpu; 75436acfc65SAlexander Motin low->cs_load = lgroup.cs_load; 75536acfc65SAlexander Motin } 75636acfc65SAlexander Motin } 75736acfc65SAlexander Motin if (match & CPU_SEARCH_HIGHEST) 75870801abeSAlexander Motin if (hgroup.cs_cpu >= 0 && 7596022f0bcSAlexander Motin (load > hload || 7606022f0bcSAlexander Motin (load == hload && hgroup.cs_load > high->cs_load))) { 76136acfc65SAlexander Motin hload = load; 76236acfc65SAlexander Motin high->cs_cpu = hgroup.cs_cpu; 76336acfc65SAlexander Motin high->cs_load = hgroup.cs_load; 76436acfc65SAlexander Motin } 76570801abeSAlexander Motin if (child) { 76670801abeSAlexander Motin i--; 76770801abeSAlexander Motin if (i == 0 && CPU_EMPTY(&cpumask)) 76870801abeSAlexander Motin break; 76958909b74SAlexander Motin } 77058909b74SAlexander Motin #ifndef HAVE_INLINE_FFSL 77158909b74SAlexander Motin else 77270801abeSAlexander Motin cpu--; 77358909b74SAlexander Motin #endif 77462fa74d9SJeff Roberson } 77562fa74d9SJeff Roberson return (total); 77662fa74d9SJeff Roberson } 77762fa74d9SJeff Roberson 77862fa74d9SJeff Roberson /* 77962fa74d9SJeff Roberson * cpu_search instantiations must pass constants to maintain the inline 78062fa74d9SJeff Roberson * optimization. 78162fa74d9SJeff Roberson */ 78262fa74d9SJeff Roberson int 78336acfc65SAlexander Motin cpu_search_lowest(const struct cpu_group *cg, struct cpu_search *low) 78462fa74d9SJeff Roberson { 78562fa74d9SJeff Roberson return cpu_search(cg, low, NULL, CPU_SEARCH_LOWEST); 78662fa74d9SJeff Roberson } 78762fa74d9SJeff Roberson 78862fa74d9SJeff Roberson int 78936acfc65SAlexander Motin cpu_search_highest(const struct cpu_group *cg, struct cpu_search *high) 79062fa74d9SJeff Roberson { 79162fa74d9SJeff Roberson return cpu_search(cg, NULL, high, CPU_SEARCH_HIGHEST); 79262fa74d9SJeff Roberson } 79362fa74d9SJeff Roberson 79462fa74d9SJeff Roberson int 79536acfc65SAlexander Motin cpu_search_both(const struct cpu_group *cg, struct cpu_search *low, 79662fa74d9SJeff Roberson struct cpu_search *high) 79762fa74d9SJeff Roberson { 79862fa74d9SJeff Roberson return cpu_search(cg, low, high, CPU_SEARCH_BOTH); 79962fa74d9SJeff Roberson } 80062fa74d9SJeff Roberson 80162fa74d9SJeff Roberson /* 80262fa74d9SJeff Roberson * Find the cpu with the least load via the least loaded path that has a 80362fa74d9SJeff Roberson * lowpri greater than pri pri. A pri of -1 indicates any priority is 80462fa74d9SJeff Roberson * acceptable. 80562fa74d9SJeff Roberson */ 80662fa74d9SJeff Roberson static inline int 80736acfc65SAlexander Motin sched_lowest(const struct cpu_group *cg, cpuset_t mask, int pri, int maxload, 80836acfc65SAlexander Motin int prefer) 80962fa74d9SJeff Roberson { 81062fa74d9SJeff Roberson struct cpu_search low; 81162fa74d9SJeff Roberson 81262fa74d9SJeff Roberson low.cs_cpu = -1; 81336acfc65SAlexander Motin low.cs_prefer = prefer; 81462fa74d9SJeff Roberson low.cs_mask = mask; 81536acfc65SAlexander Motin low.cs_pri = pri; 81636acfc65SAlexander Motin low.cs_limit = maxload; 81762fa74d9SJeff Roberson cpu_search_lowest(cg, &low); 81862fa74d9SJeff Roberson return low.cs_cpu; 81962fa74d9SJeff Roberson } 82062fa74d9SJeff Roberson 82162fa74d9SJeff Roberson /* 82262fa74d9SJeff Roberson * Find the cpu with the highest load via the highest loaded path. 82362fa74d9SJeff Roberson */ 82462fa74d9SJeff Roberson static inline int 82536acfc65SAlexander Motin sched_highest(const struct cpu_group *cg, cpuset_t mask, int minload) 82662fa74d9SJeff Roberson { 82762fa74d9SJeff Roberson struct cpu_search high; 82862fa74d9SJeff Roberson 82962fa74d9SJeff Roberson high.cs_cpu = -1; 83062fa74d9SJeff Roberson high.cs_mask = mask; 83162fa74d9SJeff Roberson high.cs_limit = minload; 83262fa74d9SJeff Roberson cpu_search_highest(cg, &high); 83362fa74d9SJeff Roberson return high.cs_cpu; 83462fa74d9SJeff Roberson } 83562fa74d9SJeff Roberson 83662fa74d9SJeff Roberson static void 83762fa74d9SJeff Roberson sched_balance_group(struct cpu_group *cg) 83862fa74d9SJeff Roberson { 839018ff686SJeff Roberson struct tdq *tdq; 84036acfc65SAlexander Motin cpuset_t hmask, lmask; 84136acfc65SAlexander Motin int high, low, anylow; 84262fa74d9SJeff Roberson 84336acfc65SAlexander Motin CPU_FILL(&hmask); 84462fa74d9SJeff Roberson for (;;) { 84597e9382dSDon Lewis high = sched_highest(cg, hmask, 2); 84636acfc65SAlexander Motin /* Stop if there is no more CPU with transferrable threads. */ 84736acfc65SAlexander Motin if (high == -1) 84862fa74d9SJeff Roberson break; 84936acfc65SAlexander Motin CPU_CLR(high, &hmask); 85036acfc65SAlexander Motin CPU_COPY(&hmask, &lmask); 85136acfc65SAlexander Motin /* Stop if there is no more CPU left for low. */ 85236acfc65SAlexander Motin if (CPU_EMPTY(&lmask)) 85362fa74d9SJeff Roberson break; 85436acfc65SAlexander Motin anylow = 1; 855018ff686SJeff Roberson tdq = TDQ_CPU(high); 85636acfc65SAlexander Motin nextlow: 857018ff686SJeff Roberson low = sched_lowest(cg, lmask, -1, tdq->tdq_load - 1, high); 85836acfc65SAlexander Motin /* Stop if we looked well and found no less loaded CPU. */ 85936acfc65SAlexander Motin if (anylow && low == -1) 86036acfc65SAlexander Motin break; 86136acfc65SAlexander Motin /* Go to next high if we found no less loaded CPU. */ 86236acfc65SAlexander Motin if (low == -1) 86336acfc65SAlexander Motin continue; 86436acfc65SAlexander Motin /* Transfer thread from high to low. */ 865018ff686SJeff Roberson if (sched_balance_pair(tdq, TDQ_CPU(low))) { 86636acfc65SAlexander Motin /* CPU that got thread can no longer be a donor. */ 86736acfc65SAlexander Motin CPU_CLR(low, &hmask); 86836acfc65SAlexander Motin } else { 86962fa74d9SJeff Roberson /* 87036acfc65SAlexander Motin * If failed, then there is no threads on high 87136acfc65SAlexander Motin * that can run on this low. Drop low from low 87236acfc65SAlexander Motin * mask and look for different one. 87362fa74d9SJeff Roberson */ 87436acfc65SAlexander Motin CPU_CLR(low, &lmask); 87536acfc65SAlexander Motin anylow = 0; 87636acfc65SAlexander Motin goto nextlow; 87762fa74d9SJeff Roberson } 87836acfc65SAlexander Motin } 87962fa74d9SJeff Roberson } 88062fa74d9SJeff Roberson 88162fa74d9SJeff Roberson static void 88262375ca8SEd Schouten sched_balance(void) 883356500a3SJeff Roberson { 8847fcf154aSJeff Roberson struct tdq *tdq; 885356500a3SJeff Roberson 8860567b6ccSWarner Losh balance_ticks = max(balance_interval / 2, 1) + 887b250ad34SWarner Losh (sched_random() % balance_interval); 8887fcf154aSJeff Roberson tdq = TDQ_SELF(); 8897fcf154aSJeff Roberson TDQ_UNLOCK(tdq); 89062fa74d9SJeff Roberson sched_balance_group(cpu_top); 8917fcf154aSJeff Roberson TDQ_LOCK(tdq); 892cac77d04SJeff Roberson } 89386f8ae96SJeff Roberson 894ae7a6b38SJeff Roberson /* 895ae7a6b38SJeff Roberson * Lock two thread queues using their address to maintain lock order. 896ae7a6b38SJeff Roberson */ 897ae7a6b38SJeff Roberson static void 898ae7a6b38SJeff Roberson tdq_lock_pair(struct tdq *one, struct tdq *two) 899ae7a6b38SJeff Roberson { 900ae7a6b38SJeff Roberson if (one < two) { 901ae7a6b38SJeff Roberson TDQ_LOCK(one); 902ae7a6b38SJeff Roberson TDQ_LOCK_FLAGS(two, MTX_DUPOK); 903ae7a6b38SJeff Roberson } else { 904ae7a6b38SJeff Roberson TDQ_LOCK(two); 905ae7a6b38SJeff Roberson TDQ_LOCK_FLAGS(one, MTX_DUPOK); 906ae7a6b38SJeff Roberson } 907ae7a6b38SJeff Roberson } 908ae7a6b38SJeff Roberson 909ae7a6b38SJeff Roberson /* 9107fcf154aSJeff Roberson * Unlock two thread queues. Order is not important here. 9117fcf154aSJeff Roberson */ 9127fcf154aSJeff Roberson static void 9137fcf154aSJeff Roberson tdq_unlock_pair(struct tdq *one, struct tdq *two) 9147fcf154aSJeff Roberson { 9157fcf154aSJeff Roberson TDQ_UNLOCK(one); 9167fcf154aSJeff Roberson TDQ_UNLOCK(two); 9177fcf154aSJeff Roberson } 9187fcf154aSJeff Roberson 9197fcf154aSJeff Roberson /* 920ae7a6b38SJeff Roberson * Transfer load between two imbalanced thread queues. 921ae7a6b38SJeff Roberson */ 92262fa74d9SJeff Roberson static int 923ad1e7d28SJulian Elischer sched_balance_pair(struct tdq *high, struct tdq *low) 924cac77d04SJeff Roberson { 92597e9382dSDon Lewis struct thread *td; 926880bf8b9SMarius Strobl int cpu; 927cac77d04SJeff Roberson 928ae7a6b38SJeff Roberson tdq_lock_pair(high, low); 92997e9382dSDon Lewis td = NULL; 930155b9987SJeff Roberson /* 93197e9382dSDon Lewis * Transfer a thread from high to low. 932155b9987SJeff Roberson */ 93336acfc65SAlexander Motin if (high->tdq_transferable != 0 && high->tdq_load > low->tdq_load && 93497e9382dSDon Lewis (td = tdq_move(high, low)) != NULL) { 935a5423ea3SJeff Roberson /* 93697e9382dSDon Lewis * In case the target isn't the current cpu notify it of the 93797e9382dSDon Lewis * new load, possibly sending an IPI to force it to reschedule. 938a5423ea3SJeff Roberson */ 939880bf8b9SMarius Strobl cpu = TDQ_ID(low); 940880bf8b9SMarius Strobl if (cpu != PCPU_GET(cpuid)) 94197e9382dSDon Lewis tdq_notify(low, td); 942ae7a6b38SJeff Roberson } 9437fcf154aSJeff Roberson tdq_unlock_pair(high, low); 94497e9382dSDon Lewis return (td != NULL); 945356500a3SJeff Roberson } 946356500a3SJeff Roberson 947ae7a6b38SJeff Roberson /* 948ae7a6b38SJeff Roberson * Move a thread from one thread queue to another. 949ae7a6b38SJeff Roberson */ 95097e9382dSDon Lewis static struct thread * 951ae7a6b38SJeff Roberson tdq_move(struct tdq *from, struct tdq *to) 952356500a3SJeff Roberson { 953ae7a6b38SJeff Roberson struct thread *td; 954ae7a6b38SJeff Roberson struct tdq *tdq; 955ae7a6b38SJeff Roberson int cpu; 956356500a3SJeff Roberson 9577fcf154aSJeff Roberson TDQ_LOCK_ASSERT(from, MA_OWNED); 9587fcf154aSJeff Roberson TDQ_LOCK_ASSERT(to, MA_OWNED); 9597fcf154aSJeff Roberson 960ad1e7d28SJulian Elischer tdq = from; 961ae7a6b38SJeff Roberson cpu = TDQ_ID(to); 9629727e637SJeff Roberson td = tdq_steal(tdq, cpu); 9639727e637SJeff Roberson if (td == NULL) 96497e9382dSDon Lewis return (NULL); 965*61a74c5cSJeff Roberson 966ae7a6b38SJeff Roberson /* 967*61a74c5cSJeff Roberson * Although the run queue is locked the thread may be 968*61a74c5cSJeff Roberson * blocked. We can not set the lock until it is unblocked. 969ae7a6b38SJeff Roberson */ 970*61a74c5cSJeff Roberson thread_lock_block_wait(td); 971ae7a6b38SJeff Roberson sched_rem(td); 972*61a74c5cSJeff Roberson THREAD_LOCKPTR_ASSERT(td, TDQ_LOCKPTR(from)); 973ae7a6b38SJeff Roberson td->td_lock = TDQ_LOCKPTR(to); 974*61a74c5cSJeff Roberson td_get_sched(td)->ts_cpu = cpu; 975ae7a6b38SJeff Roberson tdq_add(to, td, SRQ_YIELDING); 976*61a74c5cSJeff Roberson 97797e9382dSDon Lewis return (td); 978356500a3SJeff Roberson } 97922bf7d9aSJeff Roberson 980ae7a6b38SJeff Roberson /* 981ae7a6b38SJeff Roberson * This tdq has idled. Try to steal a thread from another cpu and switch 982ae7a6b38SJeff Roberson * to it. 983ae7a6b38SJeff Roberson */ 98480f86c9fSJeff Roberson static int 985ad1e7d28SJulian Elischer tdq_idled(struct tdq *tdq) 98622bf7d9aSJeff Roberson { 98762fa74d9SJeff Roberson struct cpu_group *cg; 988ad1e7d28SJulian Elischer struct tdq *steal; 989c76ee827SJeff Roberson cpuset_t mask; 99097e9382dSDon Lewis int cpu, switchcnt; 99180f86c9fSJeff Roberson 99297e9382dSDon Lewis if (smp_started == 0 || steal_idle == 0 || tdq->tdq_cg == NULL) 99388f530ccSJeff Roberson return (1); 994c76ee827SJeff Roberson CPU_FILL(&mask); 995c76ee827SJeff Roberson CPU_CLR(PCPU_GET(cpuid), &mask); 99697e9382dSDon Lewis restart: 99797e9382dSDon Lewis switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt; 99897e9382dSDon Lewis for (cg = tdq->tdq_cg; ; ) { 99997e9382dSDon Lewis cpu = sched_highest(cg, mask, steal_thresh); 100097e9382dSDon Lewis /* 100197e9382dSDon Lewis * We were assigned a thread but not preempted. Returning 100297e9382dSDon Lewis * 0 here will cause our caller to switch to it. 100397e9382dSDon Lewis */ 100497e9382dSDon Lewis if (tdq->tdq_load) 100597e9382dSDon Lewis return (0); 100662fa74d9SJeff Roberson if (cpu == -1) { 100762fa74d9SJeff Roberson cg = cg->cg_parent; 100897e9382dSDon Lewis if (cg == NULL) 100997e9382dSDon Lewis return (1); 101080f86c9fSJeff Roberson continue; 10117b8bfa0dSJeff Roberson } 10127b8bfa0dSJeff Roberson steal = TDQ_CPU(cpu); 101397e9382dSDon Lewis /* 101497e9382dSDon Lewis * The data returned by sched_highest() is stale and 101597e9382dSDon Lewis * the chosen CPU no longer has an eligible thread. 101697e9382dSDon Lewis * 101797e9382dSDon Lewis * Testing this ahead of tdq_lock_pair() only catches 101897e9382dSDon Lewis * this situation about 20% of the time on an 8 core 101997e9382dSDon Lewis * 16 thread Ryzen 7, but it still helps performance. 102097e9382dSDon Lewis */ 102197e9382dSDon Lewis if (steal->tdq_load < steal_thresh || 102297e9382dSDon Lewis steal->tdq_transferable == 0) 102397e9382dSDon Lewis goto restart; 10247fcf154aSJeff Roberson tdq_lock_pair(tdq, steal); 102597e9382dSDon Lewis /* 102697e9382dSDon Lewis * We were assigned a thread while waiting for the locks. 102797e9382dSDon Lewis * Switch to it now instead of stealing a thread. 102897e9382dSDon Lewis */ 102997e9382dSDon Lewis if (tdq->tdq_load) 103097e9382dSDon Lewis break; 103197e9382dSDon Lewis /* 103297e9382dSDon Lewis * The data returned by sched_highest() is stale and 103397e9382dSDon Lewis * the chosen CPU no longer has an eligible thread, or 103497e9382dSDon Lewis * we were preempted and the CPU loading info may be out 103597e9382dSDon Lewis * of date. The latter is rare. In either case restart 103697e9382dSDon Lewis * the search. 103797e9382dSDon Lewis */ 103897e9382dSDon Lewis if (steal->tdq_load < steal_thresh || 103997e9382dSDon Lewis steal->tdq_transferable == 0 || 104097e9382dSDon Lewis switchcnt != tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt) { 10417fcf154aSJeff Roberson tdq_unlock_pair(tdq, steal); 104297e9382dSDon Lewis goto restart; 104362fa74d9SJeff Roberson } 104462fa74d9SJeff Roberson /* 104597e9382dSDon Lewis * Steal the thread and switch to it. 104662fa74d9SJeff Roberson */ 104797e9382dSDon Lewis if (tdq_move(steal, tdq) != NULL) 104897e9382dSDon Lewis break; 104997e9382dSDon Lewis /* 105097e9382dSDon Lewis * We failed to acquire a thread even though it looked 105197e9382dSDon Lewis * like one was available. This could be due to affinity 105297e9382dSDon Lewis * restrictions or for other reasons. Loop again after 105397e9382dSDon Lewis * removing this CPU from the set. The restart logic 105497e9382dSDon Lewis * above does not restore this CPU to the set due to the 105597e9382dSDon Lewis * likelyhood of failing here again. 105697e9382dSDon Lewis */ 105797e9382dSDon Lewis CPU_CLR(cpu, &mask); 105862fa74d9SJeff Roberson tdq_unlock_pair(tdq, steal); 105980f86c9fSJeff Roberson } 1060ae7a6b38SJeff Roberson TDQ_UNLOCK(steal); 10618df78c41SJeff Roberson mi_switch(SW_VOL | SWT_IDLE, NULL); 1062ae7a6b38SJeff Roberson thread_unlock(curthread); 10637b8bfa0dSJeff Roberson return (0); 106422bf7d9aSJeff Roberson } 106522bf7d9aSJeff Roberson 1066ae7a6b38SJeff Roberson /* 1067ae7a6b38SJeff Roberson * Notify a remote cpu of new work. Sends an IPI if criteria are met. 1068ae7a6b38SJeff Roberson */ 106922bf7d9aSJeff Roberson static void 107027ee18adSRyan Stone tdq_notify(struct tdq *tdq, struct thread *td) 107122bf7d9aSJeff Roberson { 107202f0ff6dSJohn Baldwin struct thread *ctd; 107327ee18adSRyan Stone int pri; 10747b8bfa0dSJeff Roberson int cpu; 107522bf7d9aSJeff Roberson 10767789ab32SMark Johnston if (tdq->tdq_owepreempt) 1077ff256d9cSJeff Roberson return; 107827ee18adSRyan Stone cpu = td_get_sched(td)->ts_cpu; 107927ee18adSRyan Stone pri = td->td_priority; 108002f0ff6dSJohn Baldwin ctd = pcpu_find(cpu)->pc_curthread; 108102f0ff6dSJohn Baldwin if (!sched_shouldpreempt(pri, ctd->td_priority, 1)) 10826b2f763fSJeff Roberson return; 108379654969SAlexander Motin 108479654969SAlexander Motin /* 1085ae9e9b4fSAlexander Motin * Make sure that our caller's earlier update to tdq_load is 1086ae9e9b4fSAlexander Motin * globally visible before we read tdq_cpu_idle. Idle thread 108779654969SAlexander Motin * accesses both of them without locks, and the order is important. 108879654969SAlexander Motin */ 1089e8677f38SKonstantin Belousov atomic_thread_fence_seq_cst(); 109079654969SAlexander Motin 109102f0ff6dSJohn Baldwin if (TD_IS_IDLETHREAD(ctd)) { 10921690c6c1SJeff Roberson /* 10936c47aaaeSJeff Roberson * If the MD code has an idle wakeup routine try that before 10946c47aaaeSJeff Roberson * falling back to IPI. 10956c47aaaeSJeff Roberson */ 10969f9ad565SAlexander Motin if (!tdq->tdq_cpu_idle || cpu_idle_wakeup(cpu)) 10976c47aaaeSJeff Roberson return; 10981690c6c1SJeff Roberson } 10997789ab32SMark Johnston 11007789ab32SMark Johnston /* 11017789ab32SMark Johnston * The run queues have been updated, so any switch on the remote CPU 11027789ab32SMark Johnston * will satisfy the preemption request. 11037789ab32SMark Johnston */ 11047789ab32SMark Johnston tdq->tdq_owepreempt = 1; 1105d9d8d144SJohn Baldwin ipi_cpu(cpu, IPI_PREEMPT); 110622bf7d9aSJeff Roberson } 110722bf7d9aSJeff Roberson 1108ae7a6b38SJeff Roberson /* 1109ae7a6b38SJeff Roberson * Steals load from a timeshare queue. Honors the rotating queue head 1110ae7a6b38SJeff Roberson * index. 1111ae7a6b38SJeff Roberson */ 11129727e637SJeff Roberson static struct thread * 111362fa74d9SJeff Roberson runq_steal_from(struct runq *rq, int cpu, u_char start) 1114ae7a6b38SJeff Roberson { 1115ae7a6b38SJeff Roberson struct rqbits *rqb; 1116ae7a6b38SJeff Roberson struct rqhead *rqh; 111736acfc65SAlexander Motin struct thread *td, *first; 1118ae7a6b38SJeff Roberson int bit; 1119ae7a6b38SJeff Roberson int i; 1120ae7a6b38SJeff Roberson 1121ae7a6b38SJeff Roberson rqb = &rq->rq_status; 1122ae7a6b38SJeff Roberson bit = start & (RQB_BPW -1); 112336acfc65SAlexander Motin first = NULL; 1124ae7a6b38SJeff Roberson again: 1125ae7a6b38SJeff Roberson for (i = RQB_WORD(start); i < RQB_LEN; bit = 0, i++) { 1126ae7a6b38SJeff Roberson if (rqb->rqb_bits[i] == 0) 1127ae7a6b38SJeff Roberson continue; 11288bc713f6SJeff Roberson if (bit == 0) 11298bc713f6SJeff Roberson bit = RQB_FFS(rqb->rqb_bits[i]); 11308bc713f6SJeff Roberson for (; bit < RQB_BPW; bit++) { 11318bc713f6SJeff Roberson if ((rqb->rqb_bits[i] & (1ul << bit)) == 0) 1132ae7a6b38SJeff Roberson continue; 11338bc713f6SJeff Roberson rqh = &rq->rq_queues[bit + (i << RQB_L2BPW)]; 11349727e637SJeff Roberson TAILQ_FOREACH(td, rqh, td_runq) { 11359727e637SJeff Roberson if (first && THREAD_CAN_MIGRATE(td) && 11369727e637SJeff Roberson THREAD_CAN_SCHED(td, cpu)) 11379727e637SJeff Roberson return (td); 113836acfc65SAlexander Motin first = td; 1139ae7a6b38SJeff Roberson } 1140ae7a6b38SJeff Roberson } 11418bc713f6SJeff Roberson } 1142ae7a6b38SJeff Roberson if (start != 0) { 1143ae7a6b38SJeff Roberson start = 0; 1144ae7a6b38SJeff Roberson goto again; 1145ae7a6b38SJeff Roberson } 1146ae7a6b38SJeff Roberson 114736acfc65SAlexander Motin if (first && THREAD_CAN_MIGRATE(first) && 114836acfc65SAlexander Motin THREAD_CAN_SCHED(first, cpu)) 114936acfc65SAlexander Motin return (first); 1150ae7a6b38SJeff Roberson return (NULL); 1151ae7a6b38SJeff Roberson } 1152ae7a6b38SJeff Roberson 1153ae7a6b38SJeff Roberson /* 1154ae7a6b38SJeff Roberson * Steals load from a standard linear queue. 1155ae7a6b38SJeff Roberson */ 11569727e637SJeff Roberson static struct thread * 115762fa74d9SJeff Roberson runq_steal(struct runq *rq, int cpu) 115822bf7d9aSJeff Roberson { 115922bf7d9aSJeff Roberson struct rqhead *rqh; 116022bf7d9aSJeff Roberson struct rqbits *rqb; 11619727e637SJeff Roberson struct thread *td; 116222bf7d9aSJeff Roberson int word; 116322bf7d9aSJeff Roberson int bit; 116422bf7d9aSJeff Roberson 116522bf7d9aSJeff Roberson rqb = &rq->rq_status; 116622bf7d9aSJeff Roberson for (word = 0; word < RQB_LEN; word++) { 116722bf7d9aSJeff Roberson if (rqb->rqb_bits[word] == 0) 116822bf7d9aSJeff Roberson continue; 116922bf7d9aSJeff Roberson for (bit = 0; bit < RQB_BPW; bit++) { 1170a2640c9bSPeter Wemm if ((rqb->rqb_bits[word] & (1ul << bit)) == 0) 117122bf7d9aSJeff Roberson continue; 117222bf7d9aSJeff Roberson rqh = &rq->rq_queues[bit + (word << RQB_L2BPW)]; 11739727e637SJeff Roberson TAILQ_FOREACH(td, rqh, td_runq) 11749727e637SJeff Roberson if (THREAD_CAN_MIGRATE(td) && 11759727e637SJeff Roberson THREAD_CAN_SCHED(td, cpu)) 11769727e637SJeff Roberson return (td); 117722bf7d9aSJeff Roberson } 117822bf7d9aSJeff Roberson } 117922bf7d9aSJeff Roberson return (NULL); 118022bf7d9aSJeff Roberson } 118122bf7d9aSJeff Roberson 1182ae7a6b38SJeff Roberson /* 1183ae7a6b38SJeff Roberson * Attempt to steal a thread in priority order from a thread queue. 1184ae7a6b38SJeff Roberson */ 11859727e637SJeff Roberson static struct thread * 118662fa74d9SJeff Roberson tdq_steal(struct tdq *tdq, int cpu) 118722bf7d9aSJeff Roberson { 11889727e637SJeff Roberson struct thread *td; 118922bf7d9aSJeff Roberson 1190ae7a6b38SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED); 11919727e637SJeff Roberson if ((td = runq_steal(&tdq->tdq_realtime, cpu)) != NULL) 11929727e637SJeff Roberson return (td); 11939727e637SJeff Roberson if ((td = runq_steal_from(&tdq->tdq_timeshare, 11949727e637SJeff Roberson cpu, tdq->tdq_ridx)) != NULL) 11959727e637SJeff Roberson return (td); 119662fa74d9SJeff Roberson return (runq_steal(&tdq->tdq_idle, cpu)); 119722bf7d9aSJeff Roberson } 119880f86c9fSJeff Roberson 1199ae7a6b38SJeff Roberson /* 1200ae7a6b38SJeff Roberson * Sets the thread lock and ts_cpu to match the requested cpu. Unlocks the 12017fcf154aSJeff Roberson * current lock and returns with the assigned queue locked. 1202ae7a6b38SJeff Roberson */ 1203ae7a6b38SJeff Roberson static inline struct tdq * 12049727e637SJeff Roberson sched_setcpu(struct thread *td, int cpu, int flags) 120580f86c9fSJeff Roberson { 12069727e637SJeff Roberson 1207ae7a6b38SJeff Roberson struct tdq *tdq; 1208*61a74c5cSJeff Roberson struct mtx *mtx; 120980f86c9fSJeff Roberson 12109727e637SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 1211ae7a6b38SJeff Roberson tdq = TDQ_CPU(cpu); 121293ccd6bfSKonstantin Belousov td_get_sched(td)->ts_cpu = cpu; 12139727e637SJeff Roberson /* 12149727e637SJeff Roberson * If the lock matches just return the queue. 12159727e637SJeff Roberson */ 1216*61a74c5cSJeff Roberson if (td->td_lock == TDQ_LOCKPTR(tdq)) { 1217*61a74c5cSJeff Roberson KASSERT((flags & SRQ_HOLD) == 0, 1218*61a74c5cSJeff Roberson ("sched_setcpu: Invalid lock for SRQ_HOLD")); 1219ae7a6b38SJeff Roberson return (tdq); 1220ae7a6b38SJeff Roberson } 1221*61a74c5cSJeff Roberson 122280f86c9fSJeff Roberson /* 1223ae7a6b38SJeff Roberson * The hard case, migration, we need to block the thread first to 1224ae7a6b38SJeff Roberson * prevent order reversals with other cpus locks. 12257b8bfa0dSJeff Roberson */ 1226b0b9dee5SAttilio Rao spinlock_enter(); 1227*61a74c5cSJeff Roberson mtx = thread_lock_block(td); 1228*61a74c5cSJeff Roberson if ((flags & SRQ_HOLD) == 0) 1229*61a74c5cSJeff Roberson mtx_unlock_spin(mtx); 1230ae7a6b38SJeff Roberson TDQ_LOCK(tdq); 1231ae7a6b38SJeff Roberson thread_lock_unblock(td, TDQ_LOCKPTR(tdq)); 1232b0b9dee5SAttilio Rao spinlock_exit(); 1233ae7a6b38SJeff Roberson return (tdq); 123480f86c9fSJeff Roberson } 12352454aaf5SJeff Roberson 12368df78c41SJeff Roberson SCHED_STAT_DEFINE(pickcpu_intrbind, "Soft interrupt binding"); 12378df78c41SJeff Roberson SCHED_STAT_DEFINE(pickcpu_idle_affinity, "Picked idle cpu based on affinity"); 12388df78c41SJeff Roberson SCHED_STAT_DEFINE(pickcpu_affinity, "Picked cpu based on affinity"); 12398df78c41SJeff Roberson SCHED_STAT_DEFINE(pickcpu_lowest, "Selected lowest load"); 12408df78c41SJeff Roberson SCHED_STAT_DEFINE(pickcpu_local, "Migrated to current cpu"); 12418df78c41SJeff Roberson SCHED_STAT_DEFINE(pickcpu_migration, "Selection may have caused migration"); 12428df78c41SJeff Roberson 1243ae7a6b38SJeff Roberson static int 12449727e637SJeff Roberson sched_pickcpu(struct thread *td, int flags) 1245ae7a6b38SJeff Roberson { 124636acfc65SAlexander Motin struct cpu_group *cg, *ccg; 12479727e637SJeff Roberson struct td_sched *ts; 1248ae7a6b38SJeff Roberson struct tdq *tdq; 1249c76ee827SJeff Roberson cpuset_t mask; 1250c9205e35SAlexander Motin int cpu, pri, self, intr; 12517b8bfa0dSJeff Roberson 125262fa74d9SJeff Roberson self = PCPU_GET(cpuid); 125393ccd6bfSKonstantin Belousov ts = td_get_sched(td); 1254efe67753SNathan Whitehorn KASSERT(!CPU_ABSENT(ts->ts_cpu), ("sched_pickcpu: Start scheduler on " 1255efe67753SNathan Whitehorn "absent CPU %d for thread %s.", ts->ts_cpu, td->td_name)); 12567b8bfa0dSJeff Roberson if (smp_started == 0) 12577b8bfa0dSJeff Roberson return (self); 125828994a58SJeff Roberson /* 125928994a58SJeff Roberson * Don't migrate a running thread from sched_switch(). 126028994a58SJeff Roberson */ 126162fa74d9SJeff Roberson if ((flags & SRQ_OURSELF) || !THREAD_CAN_MIGRATE(td)) 126262fa74d9SJeff Roberson return (ts->ts_cpu); 12637b8bfa0dSJeff Roberson /* 126462fa74d9SJeff Roberson * Prefer to run interrupt threads on the processors that generate 126562fa74d9SJeff Roberson * the interrupt. 12667b8bfa0dSJeff Roberson */ 126762fa74d9SJeff Roberson if (td->td_priority <= PRI_MAX_ITHD && THREAD_CAN_SCHED(td, self) && 1268c9205e35SAlexander Motin curthread->td_intr_nesting_level) { 1269c55dc51cSAlexander Motin tdq = TDQ_SELF(); 1270c55dc51cSAlexander Motin if (tdq->tdq_lowpri >= PRI_MIN_IDLE) { 1271c55dc51cSAlexander Motin SCHED_STAT_INC(pickcpu_idle_affinity); 1272c55dc51cSAlexander Motin return (self); 1273c55dc51cSAlexander Motin } 127462fa74d9SJeff Roberson ts->ts_cpu = self; 1275c9205e35SAlexander Motin intr = 1; 1276c55dc51cSAlexander Motin cg = tdq->tdq_cg; 1277c55dc51cSAlexander Motin goto llc; 1278c55dc51cSAlexander Motin } else { 1279c9205e35SAlexander Motin intr = 0; 1280c55dc51cSAlexander Motin tdq = TDQ_CPU(ts->ts_cpu); 1281c55dc51cSAlexander Motin cg = tdq->tdq_cg; 1282c55dc51cSAlexander Motin } 12837b8bfa0dSJeff Roberson /* 128436acfc65SAlexander Motin * If the thread can run on the last cpu and the affinity has not 12850127914cSEric van Gyzen * expired and it is idle, run it there. 12867b8bfa0dSJeff Roberson */ 128736acfc65SAlexander Motin if (THREAD_CAN_SCHED(td, ts->ts_cpu) && 128836acfc65SAlexander Motin tdq->tdq_lowpri >= PRI_MIN_IDLE && 128936acfc65SAlexander Motin SCHED_AFFINITY(ts, CG_SHARE_L2)) { 1290c55dc51cSAlexander Motin if (cg->cg_flags & CG_FLAG_THREAD) { 1291176dd236SAlexander Motin /* Check all SMT threads for being idle. */ 1292176dd236SAlexander Motin for (cpu = CPU_FFS(&cg->cg_mask) - 1; ; cpu++) { 1293176dd236SAlexander Motin if (CPU_ISSET(cpu, &cg->cg_mask) && 1294176dd236SAlexander Motin TDQ_CPU(cpu)->tdq_lowpri < PRI_MIN_IDLE) 129562fa74d9SJeff Roberson break; 1296176dd236SAlexander Motin if (cpu >= mp_maxid) { 1297176dd236SAlexander Motin SCHED_STAT_INC(pickcpu_idle_affinity); 1298176dd236SAlexander Motin return (ts->ts_cpu); 129936acfc65SAlexander Motin } 1300176dd236SAlexander Motin } 1301176dd236SAlexander Motin } else { 130236acfc65SAlexander Motin SCHED_STAT_INC(pickcpu_idle_affinity); 130336acfc65SAlexander Motin return (ts->ts_cpu); 130436acfc65SAlexander Motin } 130536acfc65SAlexander Motin } 1306c55dc51cSAlexander Motin llc: 130736acfc65SAlexander Motin /* 130836acfc65SAlexander Motin * Search for the last level cache CPU group in the tree. 1309c9205e35SAlexander Motin * Skip SMT, identical groups and caches with expired affinity. 1310c9205e35SAlexander Motin * Interrupt threads affinity is explicit and never expires. 131136acfc65SAlexander Motin */ 131236acfc65SAlexander Motin for (ccg = NULL; cg != NULL; cg = cg->cg_parent) { 131336acfc65SAlexander Motin if (cg->cg_flags & CG_FLAG_THREAD) 131436acfc65SAlexander Motin continue; 1315c9205e35SAlexander Motin if (cg->cg_children == 1 || cg->cg_count == 1) 1316c9205e35SAlexander Motin continue; 1317c9205e35SAlexander Motin if (cg->cg_level == CG_SHARE_NONE || 1318c9205e35SAlexander Motin (!intr && !SCHED_AFFINITY(ts, cg->cg_level))) 131936acfc65SAlexander Motin continue; 132036acfc65SAlexander Motin ccg = cg; 132136acfc65SAlexander Motin } 1322c9205e35SAlexander Motin /* Found LLC shared by all CPUs, so do a global search. */ 1323c9205e35SAlexander Motin if (ccg == cpu_top) 1324c9205e35SAlexander Motin ccg = NULL; 132562fa74d9SJeff Roberson cpu = -1; 1326c76ee827SJeff Roberson mask = td->td_cpuset->cs_mask; 1327c9205e35SAlexander Motin pri = td->td_priority; 1328c9205e35SAlexander Motin /* 1329c9205e35SAlexander Motin * Try hard to keep interrupts within found LLC. Search the LLC for 1330c9205e35SAlexander Motin * the least loaded CPU we can run now. For NUMA systems it should 1331c9205e35SAlexander Motin * be within target domain, and it also reduces scheduling overhead. 1332c9205e35SAlexander Motin */ 1333c9205e35SAlexander Motin if (ccg != NULL && intr) { 1334c9205e35SAlexander Motin cpu = sched_lowest(ccg, mask, pri, INT_MAX, ts->ts_cpu); 1335c9205e35SAlexander Motin if (cpu >= 0) 1336c9205e35SAlexander Motin SCHED_STAT_INC(pickcpu_intrbind); 1337c9205e35SAlexander Motin } else 1338c9205e35SAlexander Motin /* Search the LLC for the least loaded idle CPU we can run now. */ 1339c9205e35SAlexander Motin if (ccg != NULL) { 1340c9205e35SAlexander Motin cpu = sched_lowest(ccg, mask, max(pri, PRI_MAX_TIMESHARE), 134136acfc65SAlexander Motin INT_MAX, ts->ts_cpu); 1342c9205e35SAlexander Motin if (cpu >= 0) 1343c9205e35SAlexander Motin SCHED_STAT_INC(pickcpu_affinity); 1344c9205e35SAlexander Motin } 1345c9205e35SAlexander Motin /* Search globally for the least loaded CPU we can run now. */ 1346c9205e35SAlexander Motin if (cpu < 0) { 134736acfc65SAlexander Motin cpu = sched_lowest(cpu_top, mask, pri, INT_MAX, ts->ts_cpu); 1348c9205e35SAlexander Motin if (cpu >= 0) 1349c9205e35SAlexander Motin SCHED_STAT_INC(pickcpu_lowest); 1350c9205e35SAlexander Motin } 1351c9205e35SAlexander Motin /* Search globally for the least loaded CPU. */ 1352c9205e35SAlexander Motin if (cpu < 0) { 135336acfc65SAlexander Motin cpu = sched_lowest(cpu_top, mask, -1, INT_MAX, ts->ts_cpu); 1354c9205e35SAlexander Motin if (cpu >= 0) 1355c9205e35SAlexander Motin SCHED_STAT_INC(pickcpu_lowest); 1356c9205e35SAlexander Motin } 1357bb3dfc6aSAlexander Motin KASSERT(cpu >= 0, ("sched_pickcpu: Failed to find a cpu.")); 1358efe67753SNathan Whitehorn KASSERT(!CPU_ABSENT(cpu), ("sched_pickcpu: Picked absent CPU %d.", cpu)); 135962fa74d9SJeff Roberson /* 136062fa74d9SJeff Roberson * Compare the lowest loaded cpu to current cpu. 136162fa74d9SJeff Roberson */ 1362018ff686SJeff Roberson tdq = TDQ_CPU(cpu); 1363018ff686SJeff Roberson if (THREAD_CAN_SCHED(td, self) && TDQ_SELF()->tdq_lowpri > pri && 1364018ff686SJeff Roberson tdq->tdq_lowpri < PRI_MIN_IDLE && 1365018ff686SJeff Roberson TDQ_SELF()->tdq_load <= tdq->tdq_load + 1) { 13668df78c41SJeff Roberson SCHED_STAT_INC(pickcpu_local); 136762fa74d9SJeff Roberson cpu = self; 1368c9205e35SAlexander Motin } 13698df78c41SJeff Roberson if (cpu != ts->ts_cpu) 13708df78c41SJeff Roberson SCHED_STAT_INC(pickcpu_migration); 1371ae7a6b38SJeff Roberson return (cpu); 137280f86c9fSJeff Roberson } 137362fa74d9SJeff Roberson #endif 137422bf7d9aSJeff Roberson 137522bf7d9aSJeff Roberson /* 137622bf7d9aSJeff Roberson * Pick the highest priority task we have and return it. 13770c0a98b2SJeff Roberson */ 13789727e637SJeff Roberson static struct thread * 1379ad1e7d28SJulian Elischer tdq_choose(struct tdq *tdq) 13805d7ef00cSJeff Roberson { 13819727e637SJeff Roberson struct thread *td; 13825d7ef00cSJeff Roberson 1383ae7a6b38SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED); 13849727e637SJeff Roberson td = runq_choose(&tdq->tdq_realtime); 13859727e637SJeff Roberson if (td != NULL) 13869727e637SJeff Roberson return (td); 13879727e637SJeff Roberson td = runq_choose_from(&tdq->tdq_timeshare, tdq->tdq_ridx); 13889727e637SJeff Roberson if (td != NULL) { 138912d56c0fSJohn Baldwin KASSERT(td->td_priority >= PRI_MIN_BATCH, 1390e7d50326SJeff Roberson ("tdq_choose: Invalid priority on timeshare queue %d", 13919727e637SJeff Roberson td->td_priority)); 13929727e637SJeff Roberson return (td); 139315dc847eSJeff Roberson } 13949727e637SJeff Roberson td = runq_choose(&tdq->tdq_idle); 13959727e637SJeff Roberson if (td != NULL) { 13969727e637SJeff Roberson KASSERT(td->td_priority >= PRI_MIN_IDLE, 1397e7d50326SJeff Roberson ("tdq_choose: Invalid priority on idle queue %d", 13989727e637SJeff Roberson td->td_priority)); 13999727e637SJeff Roberson return (td); 1400e7d50326SJeff Roberson } 1401e7d50326SJeff Roberson 1402e7d50326SJeff Roberson return (NULL); 1403245f3abfSJeff Roberson } 14040a016a05SJeff Roberson 1405ae7a6b38SJeff Roberson /* 1406ae7a6b38SJeff Roberson * Initialize a thread queue. 1407ae7a6b38SJeff Roberson */ 14080a016a05SJeff Roberson static void 1409018ff686SJeff Roberson tdq_setup(struct tdq *tdq, int id) 14100a016a05SJeff Roberson { 1411ae7a6b38SJeff Roberson 1412c47f202bSJeff Roberson if (bootverbose) 1413018ff686SJeff Roberson printf("ULE: setup cpu %d\n", id); 1414e7d50326SJeff Roberson runq_init(&tdq->tdq_realtime); 1415e7d50326SJeff Roberson runq_init(&tdq->tdq_timeshare); 1416d2ad694cSJeff Roberson runq_init(&tdq->tdq_idle); 1417018ff686SJeff Roberson tdq->tdq_id = id; 141862fa74d9SJeff Roberson snprintf(tdq->tdq_name, sizeof(tdq->tdq_name), 141962fa74d9SJeff Roberson "sched lock %d", (int)TDQ_ID(tdq)); 1420*61a74c5cSJeff Roberson mtx_init(&tdq->tdq_lock, tdq->tdq_name, "sched lock", MTX_SPIN); 14218f51ad55SJeff Roberson #ifdef KTR 14228f51ad55SJeff Roberson snprintf(tdq->tdq_loadname, sizeof(tdq->tdq_loadname), 14238f51ad55SJeff Roberson "CPU %d load", (int)TDQ_ID(tdq)); 14248f51ad55SJeff Roberson #endif 14250a016a05SJeff Roberson } 14260a016a05SJeff Roberson 1427c47f202bSJeff Roberson #ifdef SMP 1428c47f202bSJeff Roberson static void 1429c47f202bSJeff Roberson sched_setup_smp(void) 1430c47f202bSJeff Roberson { 1431c47f202bSJeff Roberson struct tdq *tdq; 1432c47f202bSJeff Roberson int i; 1433c47f202bSJeff Roberson 143462fa74d9SJeff Roberson cpu_top = smp_topo(); 14353aa6d94eSJohn Baldwin CPU_FOREACH(i) { 1436018ff686SJeff Roberson tdq = DPCPU_ID_PTR(i, tdq); 1437018ff686SJeff Roberson tdq_setup(tdq, i); 143862fa74d9SJeff Roberson tdq->tdq_cg = smp_topo_find(cpu_top, i); 143962fa74d9SJeff Roberson if (tdq->tdq_cg == NULL) 144062fa74d9SJeff Roberson panic("Can't find cpu group for %d\n", i); 1441c47f202bSJeff Roberson } 1442018ff686SJeff Roberson PCPU_SET(sched, DPCPU_PTR(tdq)); 144362fa74d9SJeff Roberson balance_tdq = TDQ_SELF(); 1444c47f202bSJeff Roberson } 1445c47f202bSJeff Roberson #endif 1446c47f202bSJeff Roberson 1447ae7a6b38SJeff Roberson /* 1448ae7a6b38SJeff Roberson * Setup the thread queues and initialize the topology based on MD 1449ae7a6b38SJeff Roberson * information. 1450ae7a6b38SJeff Roberson */ 145135e6168fSJeff Roberson static void 145235e6168fSJeff Roberson sched_setup(void *dummy) 145335e6168fSJeff Roberson { 1454ae7a6b38SJeff Roberson struct tdq *tdq; 1455c47f202bSJeff Roberson 14560ec896fdSJeff Roberson #ifdef SMP 1457c47f202bSJeff Roberson sched_setup_smp(); 1458749d01b0SJeff Roberson #else 1459018ff686SJeff Roberson tdq_setup(TDQ_SELF(), 0); 1460356500a3SJeff Roberson #endif 1461018ff686SJeff Roberson tdq = TDQ_SELF(); 1462ae7a6b38SJeff Roberson 1463ae7a6b38SJeff Roberson /* Add thread0's load since it's running. */ 1464ae7a6b38SJeff Roberson TDQ_LOCK(tdq); 1465e1504695SJeff Roberson thread0.td_lock = TDQ_LOCKPTR(tdq); 14669727e637SJeff Roberson tdq_load_add(tdq, &thread0); 146762fa74d9SJeff Roberson tdq->tdq_lowpri = thread0.td_priority; 1468ae7a6b38SJeff Roberson TDQ_UNLOCK(tdq); 146935e6168fSJeff Roberson } 147035e6168fSJeff Roberson 1471ae7a6b38SJeff Roberson /* 1472579895dfSAlexander Motin * This routine determines time constants after stathz and hz are setup. 1473ae7a6b38SJeff Roberson */ 1474a1d4fe69SDavid Xu /* ARGSUSED */ 1475a1d4fe69SDavid Xu static void 1476a1d4fe69SDavid Xu sched_initticks(void *dummy) 1477a1d4fe69SDavid Xu { 1478ae7a6b38SJeff Roberson int incr; 1479ae7a6b38SJeff Roberson 1480a1d4fe69SDavid Xu realstathz = stathz ? stathz : hz; 14815e5c3873SJeff Roberson sched_slice = realstathz / SCHED_SLICE_DEFAULT_DIVISOR; 14825e5c3873SJeff Roberson sched_slice_min = sched_slice / SCHED_SLICE_MIN_DIVISOR; 148337f4e025SAlexander Motin hogticks = imax(1, (2 * hz * sched_slice + realstathz / 2) / 148437f4e025SAlexander Motin realstathz); 1485a1d4fe69SDavid Xu 1486a1d4fe69SDavid Xu /* 1487e7d50326SJeff Roberson * tickincr is shifted out by 10 to avoid rounding errors due to 14883f872f85SJeff Roberson * hz not being evenly divisible by stathz on all platforms. 1489e7d50326SJeff Roberson */ 1490ae7a6b38SJeff Roberson incr = (hz << SCHED_TICK_SHIFT) / realstathz; 1491e7d50326SJeff Roberson /* 1492e7d50326SJeff Roberson * This does not work for values of stathz that are more than 1493e7d50326SJeff Roberson * 1 << SCHED_TICK_SHIFT * hz. In practice this does not happen. 1494a1d4fe69SDavid Xu */ 1495ae7a6b38SJeff Roberson if (incr == 0) 1496ae7a6b38SJeff Roberson incr = 1; 1497ae7a6b38SJeff Roberson tickincr = incr; 14987b8bfa0dSJeff Roberson #ifdef SMP 14999862717aSJeff Roberson /* 15007fcf154aSJeff Roberson * Set the default balance interval now that we know 15017fcf154aSJeff Roberson * what realstathz is. 15027fcf154aSJeff Roberson */ 15037fcf154aSJeff Roberson balance_interval = realstathz; 1504290d9060SDon Lewis balance_ticks = balance_interval; 15057b8bfa0dSJeff Roberson affinity = SCHED_AFFINITY_DEFAULT; 15067b8bfa0dSJeff Roberson #endif 1507b3f40a41SAlexander Motin if (sched_idlespinthresh < 0) 15082c27cb3aSAlexander Motin sched_idlespinthresh = 2 * max(10000, 6 * hz) / realstathz; 1509a1d4fe69SDavid Xu } 1510a1d4fe69SDavid Xu 1511a1d4fe69SDavid Xu 151235e6168fSJeff Roberson /* 1513ae7a6b38SJeff Roberson * This is the core of the interactivity algorithm. Determines a score based 1514ae7a6b38SJeff Roberson * on past behavior. It is the ratio of sleep time to run time scaled to 1515ae7a6b38SJeff Roberson * a [0, 100] integer. This is the voluntary sleep time of a process, which 1516ae7a6b38SJeff Roberson * differs from the cpu usage because it does not account for time spent 1517ae7a6b38SJeff Roberson * waiting on a run-queue. Would be prettier if we had floating point. 151857031f79SGeorge V. Neville-Neil * 151957031f79SGeorge V. Neville-Neil * When a thread's sleep time is greater than its run time the 152057031f79SGeorge V. Neville-Neil * calculation is: 152157031f79SGeorge V. Neville-Neil * 152257031f79SGeorge V. Neville-Neil * scaling factor 152357031f79SGeorge V. Neville-Neil * interactivity score = --------------------- 152457031f79SGeorge V. Neville-Neil * sleep time / run time 152557031f79SGeorge V. Neville-Neil * 152657031f79SGeorge V. Neville-Neil * 152757031f79SGeorge V. Neville-Neil * When a thread's run time is greater than its sleep time the 152857031f79SGeorge V. Neville-Neil * calculation is: 152957031f79SGeorge V. Neville-Neil * 153057031f79SGeorge V. Neville-Neil * scaling factor 153157031f79SGeorge V. Neville-Neil * interactivity score = --------------------- + scaling factor 153257031f79SGeorge V. Neville-Neil * run time / sleep time 1533ae7a6b38SJeff Roberson */ 1534ae7a6b38SJeff Roberson static int 1535ae7a6b38SJeff Roberson sched_interact_score(struct thread *td) 1536ae7a6b38SJeff Roberson { 1537ae7a6b38SJeff Roberson struct td_sched *ts; 1538ae7a6b38SJeff Roberson int div; 1539ae7a6b38SJeff Roberson 154093ccd6bfSKonstantin Belousov ts = td_get_sched(td); 1541ae7a6b38SJeff Roberson /* 1542ae7a6b38SJeff Roberson * The score is only needed if this is likely to be an interactive 1543ae7a6b38SJeff Roberson * task. Don't go through the expense of computing it if there's 1544ae7a6b38SJeff Roberson * no chance. 1545ae7a6b38SJeff Roberson */ 1546ae7a6b38SJeff Roberson if (sched_interact <= SCHED_INTERACT_HALF && 1547ae7a6b38SJeff Roberson ts->ts_runtime >= ts->ts_slptime) 1548ae7a6b38SJeff Roberson return (SCHED_INTERACT_HALF); 1549ae7a6b38SJeff Roberson 1550ae7a6b38SJeff Roberson if (ts->ts_runtime > ts->ts_slptime) { 1551ae7a6b38SJeff Roberson div = max(1, ts->ts_runtime / SCHED_INTERACT_HALF); 1552ae7a6b38SJeff Roberson return (SCHED_INTERACT_HALF + 1553ae7a6b38SJeff Roberson (SCHED_INTERACT_HALF - (ts->ts_slptime / div))); 1554ae7a6b38SJeff Roberson } 1555ae7a6b38SJeff Roberson if (ts->ts_slptime > ts->ts_runtime) { 1556ae7a6b38SJeff Roberson div = max(1, ts->ts_slptime / SCHED_INTERACT_HALF); 1557ae7a6b38SJeff Roberson return (ts->ts_runtime / div); 1558ae7a6b38SJeff Roberson } 1559ae7a6b38SJeff Roberson /* runtime == slptime */ 1560ae7a6b38SJeff Roberson if (ts->ts_runtime) 1561ae7a6b38SJeff Roberson return (SCHED_INTERACT_HALF); 1562ae7a6b38SJeff Roberson 1563ae7a6b38SJeff Roberson /* 1564ae7a6b38SJeff Roberson * This can happen if slptime and runtime are 0. 1565ae7a6b38SJeff Roberson */ 1566ae7a6b38SJeff Roberson return (0); 1567ae7a6b38SJeff Roberson 1568ae7a6b38SJeff Roberson } 1569ae7a6b38SJeff Roberson 1570ae7a6b38SJeff Roberson /* 157135e6168fSJeff Roberson * Scale the scheduling priority according to the "interactivity" of this 157235e6168fSJeff Roberson * process. 157335e6168fSJeff Roberson */ 157415dc847eSJeff Roberson static void 15758460a577SJohn Birrell sched_priority(struct thread *td) 157635e6168fSJeff Roberson { 1577e7d50326SJeff Roberson int score; 157835e6168fSJeff Roberson int pri; 157935e6168fSJeff Roberson 1580c9a8cba4SJohn Baldwin if (PRI_BASE(td->td_pri_class) != PRI_TIMESHARE) 158115dc847eSJeff Roberson return; 1582e7d50326SJeff Roberson /* 1583e7d50326SJeff Roberson * If the score is interactive we place the thread in the realtime 1584e7d50326SJeff Roberson * queue with a priority that is less than kernel and interrupt 1585e7d50326SJeff Roberson * priorities. These threads are not subject to nice restrictions. 1586e7d50326SJeff Roberson * 1587ae7a6b38SJeff Roberson * Scores greater than this are placed on the normal timeshare queue 1588e7d50326SJeff Roberson * where the priority is partially decided by the most recent cpu 1589e7d50326SJeff Roberson * utilization and the rest is decided by nice value. 1590a5423ea3SJeff Roberson * 1591a5423ea3SJeff Roberson * The nice value of the process has a linear effect on the calculated 1592a5423ea3SJeff Roberson * score. Negative nice values make it easier for a thread to be 1593a5423ea3SJeff Roberson * considered interactive. 1594e7d50326SJeff Roberson */ 1595a0f15352SJohn Baldwin score = imax(0, sched_interact_score(td) + td->td_proc->p_nice); 1596e7d50326SJeff Roberson if (score < sched_interact) { 159712d56c0fSJohn Baldwin pri = PRI_MIN_INTERACT; 159812d56c0fSJohn Baldwin pri += ((PRI_MAX_INTERACT - PRI_MIN_INTERACT + 1) / 159978920008SJohn Baldwin sched_interact) * score; 160012d56c0fSJohn Baldwin KASSERT(pri >= PRI_MIN_INTERACT && pri <= PRI_MAX_INTERACT, 16019a93305aSJeff Roberson ("sched_priority: invalid interactive priority %d score %d", 16029a93305aSJeff Roberson pri, score)); 1603e7d50326SJeff Roberson } else { 1604e7d50326SJeff Roberson pri = SCHED_PRI_MIN; 160593ccd6bfSKonstantin Belousov if (td_get_sched(td)->ts_ticks) 160693ccd6bfSKonstantin Belousov pri += min(SCHED_PRI_TICKS(td_get_sched(td)), 16075457fa23SJohn Baldwin SCHED_PRI_RANGE - 1); 1608e7d50326SJeff Roberson pri += SCHED_PRI_NICE(td->td_proc->p_nice); 160912d56c0fSJohn Baldwin KASSERT(pri >= PRI_MIN_BATCH && pri <= PRI_MAX_BATCH, 1610ae7a6b38SJeff Roberson ("sched_priority: invalid priority %d: nice %d, " 1611ae7a6b38SJeff Roberson "ticks %d ftick %d ltick %d tick pri %d", 161293ccd6bfSKonstantin Belousov pri, td->td_proc->p_nice, td_get_sched(td)->ts_ticks, 161393ccd6bfSKonstantin Belousov td_get_sched(td)->ts_ftick, td_get_sched(td)->ts_ltick, 161493ccd6bfSKonstantin Belousov SCHED_PRI_TICKS(td_get_sched(td)))); 1615e7d50326SJeff Roberson } 16168460a577SJohn Birrell sched_user_prio(td, pri); 161735e6168fSJeff Roberson 161815dc847eSJeff Roberson return; 161935e6168fSJeff Roberson } 162035e6168fSJeff Roberson 162135e6168fSJeff Roberson /* 1622d322132cSJeff Roberson * This routine enforces a maximum limit on the amount of scheduling history 1623ae7a6b38SJeff Roberson * kept. It is called after either the slptime or runtime is adjusted. This 1624ae7a6b38SJeff Roberson * function is ugly due to integer math. 1625d322132cSJeff Roberson */ 16264b60e324SJeff Roberson static void 16278460a577SJohn Birrell sched_interact_update(struct thread *td) 16284b60e324SJeff Roberson { 1629155b6ca1SJeff Roberson struct td_sched *ts; 16309a93305aSJeff Roberson u_int sum; 16313f741ca1SJeff Roberson 163293ccd6bfSKonstantin Belousov ts = td_get_sched(td); 1633ae7a6b38SJeff Roberson sum = ts->ts_runtime + ts->ts_slptime; 1634d322132cSJeff Roberson if (sum < SCHED_SLP_RUN_MAX) 1635d322132cSJeff Roberson return; 1636d322132cSJeff Roberson /* 1637155b6ca1SJeff Roberson * This only happens from two places: 1638155b6ca1SJeff Roberson * 1) We have added an unusual amount of run time from fork_exit. 1639155b6ca1SJeff Roberson * 2) We have added an unusual amount of sleep time from sched_sleep(). 1640155b6ca1SJeff Roberson */ 1641155b6ca1SJeff Roberson if (sum > SCHED_SLP_RUN_MAX * 2) { 1642ae7a6b38SJeff Roberson if (ts->ts_runtime > ts->ts_slptime) { 1643ae7a6b38SJeff Roberson ts->ts_runtime = SCHED_SLP_RUN_MAX; 1644ae7a6b38SJeff Roberson ts->ts_slptime = 1; 1645155b6ca1SJeff Roberson } else { 1646ae7a6b38SJeff Roberson ts->ts_slptime = SCHED_SLP_RUN_MAX; 1647ae7a6b38SJeff Roberson ts->ts_runtime = 1; 1648155b6ca1SJeff Roberson } 1649155b6ca1SJeff Roberson return; 1650155b6ca1SJeff Roberson } 1651155b6ca1SJeff Roberson /* 1652d322132cSJeff Roberson * If we have exceeded by more than 1/5th then the algorithm below 1653d322132cSJeff Roberson * will not bring us back into range. Dividing by two here forces 16542454aaf5SJeff Roberson * us into the range of [4/5 * SCHED_INTERACT_MAX, SCHED_INTERACT_MAX] 1655d322132cSJeff Roberson */ 165637a35e4aSJeff Roberson if (sum > (SCHED_SLP_RUN_MAX / 5) * 6) { 1657ae7a6b38SJeff Roberson ts->ts_runtime /= 2; 1658ae7a6b38SJeff Roberson ts->ts_slptime /= 2; 1659d322132cSJeff Roberson return; 1660d322132cSJeff Roberson } 1661ae7a6b38SJeff Roberson ts->ts_runtime = (ts->ts_runtime / 5) * 4; 1662ae7a6b38SJeff Roberson ts->ts_slptime = (ts->ts_slptime / 5) * 4; 1663d322132cSJeff Roberson } 1664d322132cSJeff Roberson 1665ae7a6b38SJeff Roberson /* 1666ae7a6b38SJeff Roberson * Scale back the interactivity history when a child thread is created. The 1667ae7a6b38SJeff Roberson * history is inherited from the parent but the thread may behave totally 1668ae7a6b38SJeff Roberson * differently. For example, a shell spawning a compiler process. We want 1669ae7a6b38SJeff Roberson * to learn that the compiler is behaving badly very quickly. 1670ae7a6b38SJeff Roberson */ 1671d322132cSJeff Roberson static void 16728460a577SJohn Birrell sched_interact_fork(struct thread *td) 1673d322132cSJeff Roberson { 167493ccd6bfSKonstantin Belousov struct td_sched *ts; 1675d322132cSJeff Roberson int ratio; 1676d322132cSJeff Roberson int sum; 1677d322132cSJeff Roberson 167893ccd6bfSKonstantin Belousov ts = td_get_sched(td); 167993ccd6bfSKonstantin Belousov sum = ts->ts_runtime + ts->ts_slptime; 1680d322132cSJeff Roberson if (sum > SCHED_SLP_RUN_FORK) { 1681d322132cSJeff Roberson ratio = sum / SCHED_SLP_RUN_FORK; 168293ccd6bfSKonstantin Belousov ts->ts_runtime /= ratio; 168393ccd6bfSKonstantin Belousov ts->ts_slptime /= ratio; 16844b60e324SJeff Roberson } 16854b60e324SJeff Roberson } 16864b60e324SJeff Roberson 168715dc847eSJeff Roberson /* 1688ae7a6b38SJeff Roberson * Called from proc0_init() to setup the scheduler fields. 1689ed062c8dSJulian Elischer */ 1690ed062c8dSJulian Elischer void 1691ed062c8dSJulian Elischer schedinit(void) 1692ed062c8dSJulian Elischer { 169393ccd6bfSKonstantin Belousov struct td_sched *ts0; 1694e7d50326SJeff Roberson 1695ed062c8dSJulian Elischer /* 169693ccd6bfSKonstantin Belousov * Set up the scheduler specific parts of thread0. 1697ed062c8dSJulian Elischer */ 169893ccd6bfSKonstantin Belousov ts0 = td_get_sched(&thread0); 169993ccd6bfSKonstantin Belousov ts0->ts_ltick = ticks; 170093ccd6bfSKonstantin Belousov ts0->ts_ftick = ticks; 170193ccd6bfSKonstantin Belousov ts0->ts_slice = 0; 17021408b84aSHans Petter Selasky ts0->ts_cpu = curcpu; /* set valid CPU number */ 1703ed062c8dSJulian Elischer } 1704ed062c8dSJulian Elischer 1705ed062c8dSJulian Elischer /* 170615dc847eSJeff Roberson * This is only somewhat accurate since given many processes of the same 170715dc847eSJeff Roberson * priority they will switch when their slices run out, which will be 1708e7d50326SJeff Roberson * at most sched_slice stathz ticks. 170915dc847eSJeff Roberson */ 171035e6168fSJeff Roberson int 171135e6168fSJeff Roberson sched_rr_interval(void) 171235e6168fSJeff Roberson { 1713e7d50326SJeff Roberson 1714579895dfSAlexander Motin /* Convert sched_slice from stathz to hz. */ 171537f4e025SAlexander Motin return (imax(1, (sched_slice * hz + realstathz / 2) / realstathz)); 171635e6168fSJeff Roberson } 171735e6168fSJeff Roberson 1718ae7a6b38SJeff Roberson /* 1719ae7a6b38SJeff Roberson * Update the percent cpu tracking information when it is requested or 1720ae7a6b38SJeff Roberson * the total history exceeds the maximum. We keep a sliding history of 1721ae7a6b38SJeff Roberson * tick counts that slowly decays. This is less precise than the 4BSD 1722ae7a6b38SJeff Roberson * mechanism since it happens with less regular and frequent events. 1723ae7a6b38SJeff Roberson */ 172422bf7d9aSJeff Roberson static void 17257295465eSAlexander Motin sched_pctcpu_update(struct td_sched *ts, int run) 172635e6168fSJeff Roberson { 17277295465eSAlexander Motin int t = ticks; 1728e7d50326SJeff Roberson 172978133024SMark Johnston /* 173078133024SMark Johnston * The signed difference may be negative if the thread hasn't run for 173178133024SMark Johnston * over half of the ticks rollover period. 173278133024SMark Johnston */ 173378133024SMark Johnston if ((u_int)(t - ts->ts_ltick) >= SCHED_TICK_TARG) { 1734ad1e7d28SJulian Elischer ts->ts_ticks = 0; 17357295465eSAlexander Motin ts->ts_ftick = t - SCHED_TICK_TARG; 17367295465eSAlexander Motin } else if (t - ts->ts_ftick >= SCHED_TICK_MAX) { 17377295465eSAlexander Motin ts->ts_ticks = (ts->ts_ticks / (ts->ts_ltick - ts->ts_ftick)) * 17387295465eSAlexander Motin (ts->ts_ltick - (t - SCHED_TICK_TARG)); 17397295465eSAlexander Motin ts->ts_ftick = t - SCHED_TICK_TARG; 17407295465eSAlexander Motin } 17417295465eSAlexander Motin if (run) 17427295465eSAlexander Motin ts->ts_ticks += (t - ts->ts_ltick) << SCHED_TICK_SHIFT; 17437295465eSAlexander Motin ts->ts_ltick = t; 174435e6168fSJeff Roberson } 174535e6168fSJeff Roberson 1746ae7a6b38SJeff Roberson /* 1747ae7a6b38SJeff Roberson * Adjust the priority of a thread. Move it to the appropriate run-queue 1748ae7a6b38SJeff Roberson * if necessary. This is the back-end for several priority related 1749ae7a6b38SJeff Roberson * functions. 1750ae7a6b38SJeff Roberson */ 1751e7d50326SJeff Roberson static void 1752f5c157d9SJohn Baldwin sched_thread_priority(struct thread *td, u_char prio) 175335e6168fSJeff Roberson { 1754ad1e7d28SJulian Elischer struct td_sched *ts; 175573daf66fSJeff Roberson struct tdq *tdq; 175673daf66fSJeff Roberson int oldpri; 175735e6168fSJeff Roberson 17588f51ad55SJeff Roberson KTR_POINT3(KTR_SCHED, "thread", sched_tdname(td), "prio", 17598f51ad55SJeff Roberson "prio:%d", td->td_priority, "new prio:%d", prio, 17608f51ad55SJeff Roberson KTR_ATTR_LINKED, sched_tdname(curthread)); 1761d9fae5abSAndriy Gapon SDT_PROBE3(sched, , , change__pri, td, td->td_proc, prio); 1762e87fc7cfSAndriy Gapon if (td != curthread && prio < td->td_priority) { 17638f51ad55SJeff Roberson KTR_POINT3(KTR_SCHED, "thread", sched_tdname(curthread), 17648f51ad55SJeff Roberson "lend prio", "prio:%d", td->td_priority, "new prio:%d", 17658f51ad55SJeff Roberson prio, KTR_ATTR_LINKED, sched_tdname(td)); 1766d9fae5abSAndriy Gapon SDT_PROBE4(sched, , , lend__pri, td, td->td_proc, prio, 1767b3e9e682SRyan Stone curthread); 17688f51ad55SJeff Roberson } 176993ccd6bfSKonstantin Belousov ts = td_get_sched(td); 17707b20fb19SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 1771f5c157d9SJohn Baldwin if (td->td_priority == prio) 1772f5c157d9SJohn Baldwin return; 17733f741ca1SJeff Roberson /* 17743f741ca1SJeff Roberson * If the priority has been elevated due to priority 17753f741ca1SJeff Roberson * propagation, we may have to move ourselves to a new 1776e7d50326SJeff Roberson * queue. This could be optimized to not re-add in some 1777e7d50326SJeff Roberson * cases. 1778f2b74cbfSJeff Roberson */ 17796d55b3ecSJeff Roberson if (TD_ON_RUNQ(td) && prio < td->td_priority) { 1780e7d50326SJeff Roberson sched_rem(td); 1781e7d50326SJeff Roberson td->td_priority = prio; 1782*61a74c5cSJeff Roberson sched_add(td, SRQ_BORROWING | SRQ_HOLDTD); 178373daf66fSJeff Roberson return; 178473daf66fSJeff Roberson } 17856d55b3ecSJeff Roberson /* 17866d55b3ecSJeff Roberson * If the thread is currently running we may have to adjust the lowpri 17876d55b3ecSJeff Roberson * information so other cpus are aware of our current priority. 17886d55b3ecSJeff Roberson */ 17896d55b3ecSJeff Roberson if (TD_IS_RUNNING(td)) { 1790ae7a6b38SJeff Roberson tdq = TDQ_CPU(ts->ts_cpu); 179162fa74d9SJeff Roberson oldpri = td->td_priority; 17923f741ca1SJeff Roberson td->td_priority = prio; 179362fa74d9SJeff Roberson if (prio < tdq->tdq_lowpri) 179462fa74d9SJeff Roberson tdq->tdq_lowpri = prio; 179562fa74d9SJeff Roberson else if (tdq->tdq_lowpri == oldpri) 179662fa74d9SJeff Roberson tdq_setlowpri(tdq, td); 17976d55b3ecSJeff Roberson return; 179873daf66fSJeff Roberson } 17996d55b3ecSJeff Roberson td->td_priority = prio; 1800ae7a6b38SJeff Roberson } 180135e6168fSJeff Roberson 1802f5c157d9SJohn Baldwin /* 1803f5c157d9SJohn Baldwin * Update a thread's priority when it is lent another thread's 1804f5c157d9SJohn Baldwin * priority. 1805f5c157d9SJohn Baldwin */ 1806f5c157d9SJohn Baldwin void 1807f5c157d9SJohn Baldwin sched_lend_prio(struct thread *td, u_char prio) 1808f5c157d9SJohn Baldwin { 1809f5c157d9SJohn Baldwin 1810f5c157d9SJohn Baldwin td->td_flags |= TDF_BORROWING; 1811f5c157d9SJohn Baldwin sched_thread_priority(td, prio); 1812f5c157d9SJohn Baldwin } 1813f5c157d9SJohn Baldwin 1814f5c157d9SJohn Baldwin /* 1815f5c157d9SJohn Baldwin * Restore a thread's priority when priority propagation is 1816f5c157d9SJohn Baldwin * over. The prio argument is the minimum priority the thread 1817f5c157d9SJohn Baldwin * needs to have to satisfy other possible priority lending 1818f5c157d9SJohn Baldwin * requests. If the thread's regular priority is less 1819f5c157d9SJohn Baldwin * important than prio, the thread will keep a priority boost 1820f5c157d9SJohn Baldwin * of prio. 1821f5c157d9SJohn Baldwin */ 1822f5c157d9SJohn Baldwin void 1823f5c157d9SJohn Baldwin sched_unlend_prio(struct thread *td, u_char prio) 1824f5c157d9SJohn Baldwin { 1825f5c157d9SJohn Baldwin u_char base_pri; 1826f5c157d9SJohn Baldwin 1827f5c157d9SJohn Baldwin if (td->td_base_pri >= PRI_MIN_TIMESHARE && 1828f5c157d9SJohn Baldwin td->td_base_pri <= PRI_MAX_TIMESHARE) 18298460a577SJohn Birrell base_pri = td->td_user_pri; 1830f5c157d9SJohn Baldwin else 1831f5c157d9SJohn Baldwin base_pri = td->td_base_pri; 1832f5c157d9SJohn Baldwin if (prio >= base_pri) { 1833f5c157d9SJohn Baldwin td->td_flags &= ~TDF_BORROWING; 1834f5c157d9SJohn Baldwin sched_thread_priority(td, base_pri); 1835f5c157d9SJohn Baldwin } else 1836f5c157d9SJohn Baldwin sched_lend_prio(td, prio); 1837f5c157d9SJohn Baldwin } 1838f5c157d9SJohn Baldwin 1839ae7a6b38SJeff Roberson /* 1840ae7a6b38SJeff Roberson * Standard entry for setting the priority to an absolute value. 1841ae7a6b38SJeff Roberson */ 1842f5c157d9SJohn Baldwin void 1843f5c157d9SJohn Baldwin sched_prio(struct thread *td, u_char prio) 1844f5c157d9SJohn Baldwin { 1845f5c157d9SJohn Baldwin u_char oldprio; 1846f5c157d9SJohn Baldwin 1847f5c157d9SJohn Baldwin /* First, update the base priority. */ 1848f5c157d9SJohn Baldwin td->td_base_pri = prio; 1849f5c157d9SJohn Baldwin 1850f5c157d9SJohn Baldwin /* 185150aaa791SJohn Baldwin * If the thread is borrowing another thread's priority, don't 1852f5c157d9SJohn Baldwin * ever lower the priority. 1853f5c157d9SJohn Baldwin */ 1854f5c157d9SJohn Baldwin if (td->td_flags & TDF_BORROWING && td->td_priority < prio) 1855f5c157d9SJohn Baldwin return; 1856f5c157d9SJohn Baldwin 1857f5c157d9SJohn Baldwin /* Change the real priority. */ 1858f5c157d9SJohn Baldwin oldprio = td->td_priority; 1859f5c157d9SJohn Baldwin sched_thread_priority(td, prio); 1860f5c157d9SJohn Baldwin 1861f5c157d9SJohn Baldwin /* 1862f5c157d9SJohn Baldwin * If the thread is on a turnstile, then let the turnstile update 1863f5c157d9SJohn Baldwin * its state. 1864f5c157d9SJohn Baldwin */ 1865f5c157d9SJohn Baldwin if (TD_ON_LOCK(td) && oldprio != prio) 1866f5c157d9SJohn Baldwin turnstile_adjust(td, oldprio); 1867f5c157d9SJohn Baldwin } 1868f5c157d9SJohn Baldwin 1869ae7a6b38SJeff Roberson /* 1870ae7a6b38SJeff Roberson * Set the base user priority, does not effect current running priority. 1871ae7a6b38SJeff Roberson */ 187235e6168fSJeff Roberson void 18738460a577SJohn Birrell sched_user_prio(struct thread *td, u_char prio) 18743db720fdSDavid Xu { 18753db720fdSDavid Xu 18768460a577SJohn Birrell td->td_base_user_pri = prio; 1877acbe332aSDavid Xu if (td->td_lend_user_pri <= prio) 1878fc6c30f6SJulian Elischer return; 18798460a577SJohn Birrell td->td_user_pri = prio; 18803db720fdSDavid Xu } 18813db720fdSDavid Xu 18823db720fdSDavid Xu void 18833db720fdSDavid Xu sched_lend_user_prio(struct thread *td, u_char prio) 18843db720fdSDavid Xu { 18853db720fdSDavid Xu 1886435806d3SDavid Xu THREAD_LOCK_ASSERT(td, MA_OWNED); 1887acbe332aSDavid Xu td->td_lend_user_pri = prio; 1888c8e368a9SDavid Xu td->td_user_pri = min(prio, td->td_base_user_pri); 1889c8e368a9SDavid Xu if (td->td_priority > td->td_user_pri) 1890c8e368a9SDavid Xu sched_prio(td, td->td_user_pri); 1891c8e368a9SDavid Xu else if (td->td_priority != td->td_user_pri) 1892c8e368a9SDavid Xu td->td_flags |= TDF_NEEDRESCHED; 1893435806d3SDavid Xu } 18943db720fdSDavid Xu 1895ac97da9aSMateusz Guzik /* 1896ac97da9aSMateusz Guzik * Like the above but first check if there is anything to do. 1897ac97da9aSMateusz Guzik */ 1898ac97da9aSMateusz Guzik void 1899ac97da9aSMateusz Guzik sched_lend_user_prio_cond(struct thread *td, u_char prio) 1900ac97da9aSMateusz Guzik { 1901ac97da9aSMateusz Guzik 1902ac97da9aSMateusz Guzik if (td->td_lend_user_pri != prio) 1903ac97da9aSMateusz Guzik goto lend; 1904ac97da9aSMateusz Guzik if (td->td_user_pri != min(prio, td->td_base_user_pri)) 1905ac97da9aSMateusz Guzik goto lend; 1906ac97da9aSMateusz Guzik if (td->td_priority >= td->td_user_pri) 1907ac97da9aSMateusz Guzik goto lend; 1908ac97da9aSMateusz Guzik return; 1909ac97da9aSMateusz Guzik 1910ac97da9aSMateusz Guzik lend: 1911ac97da9aSMateusz Guzik thread_lock(td); 1912ac97da9aSMateusz Guzik sched_lend_user_prio(td, prio); 1913ac97da9aSMateusz Guzik thread_unlock(td); 1914ac97da9aSMateusz Guzik } 1915ac97da9aSMateusz Guzik 19164c8a8cfcSKonstantin Belousov #ifdef SMP 1917ae7a6b38SJeff Roberson /* 191897e9382dSDon Lewis * This tdq is about to idle. Try to steal a thread from another CPU before 191997e9382dSDon Lewis * choosing the idle thread. 192097e9382dSDon Lewis */ 192197e9382dSDon Lewis static void 192297e9382dSDon Lewis tdq_trysteal(struct tdq *tdq) 192397e9382dSDon Lewis { 192497e9382dSDon Lewis struct cpu_group *cg; 192597e9382dSDon Lewis struct tdq *steal; 192697e9382dSDon Lewis cpuset_t mask; 192797e9382dSDon Lewis int cpu, i; 192897e9382dSDon Lewis 192997e9382dSDon Lewis if (smp_started == 0 || trysteal_limit == 0 || tdq->tdq_cg == NULL) 193097e9382dSDon Lewis return; 193197e9382dSDon Lewis CPU_FILL(&mask); 193297e9382dSDon Lewis CPU_CLR(PCPU_GET(cpuid), &mask); 193397e9382dSDon Lewis /* We don't want to be preempted while we're iterating. */ 193497e9382dSDon Lewis spinlock_enter(); 193597e9382dSDon Lewis TDQ_UNLOCK(tdq); 193697e9382dSDon Lewis for (i = 1, cg = tdq->tdq_cg; ; ) { 193797e9382dSDon Lewis cpu = sched_highest(cg, mask, steal_thresh); 193897e9382dSDon Lewis /* 193997e9382dSDon Lewis * If a thread was added while interrupts were disabled don't 194097e9382dSDon Lewis * steal one here. 194197e9382dSDon Lewis */ 194297e9382dSDon Lewis if (tdq->tdq_load > 0) { 194397e9382dSDon Lewis TDQ_LOCK(tdq); 194497e9382dSDon Lewis break; 194597e9382dSDon Lewis } 194697e9382dSDon Lewis if (cpu == -1) { 194797e9382dSDon Lewis i++; 194897e9382dSDon Lewis cg = cg->cg_parent; 194997e9382dSDon Lewis if (cg == NULL || i > trysteal_limit) { 195097e9382dSDon Lewis TDQ_LOCK(tdq); 195197e9382dSDon Lewis break; 195297e9382dSDon Lewis } 195397e9382dSDon Lewis continue; 195497e9382dSDon Lewis } 195597e9382dSDon Lewis steal = TDQ_CPU(cpu); 195697e9382dSDon Lewis /* 195797e9382dSDon Lewis * The data returned by sched_highest() is stale and 195897e9382dSDon Lewis * the chosen CPU no longer has an eligible thread. 195997e9382dSDon Lewis */ 196097e9382dSDon Lewis if (steal->tdq_load < steal_thresh || 196197e9382dSDon Lewis steal->tdq_transferable == 0) 196297e9382dSDon Lewis continue; 196397e9382dSDon Lewis tdq_lock_pair(tdq, steal); 196497e9382dSDon Lewis /* 196597e9382dSDon Lewis * If we get to this point, unconditonally exit the loop 196697e9382dSDon Lewis * to bound the time spent in the critcal section. 196797e9382dSDon Lewis * 196897e9382dSDon Lewis * If a thread was added while interrupts were disabled don't 196997e9382dSDon Lewis * steal one here. 197097e9382dSDon Lewis */ 197197e9382dSDon Lewis if (tdq->tdq_load > 0) { 197297e9382dSDon Lewis TDQ_UNLOCK(steal); 197397e9382dSDon Lewis break; 197497e9382dSDon Lewis } 197597e9382dSDon Lewis /* 197697e9382dSDon Lewis * The data returned by sched_highest() is stale and 197797e9382dSDon Lewis * the chosen CPU no longer has an eligible thread. 197897e9382dSDon Lewis */ 197997e9382dSDon Lewis if (steal->tdq_load < steal_thresh || 198097e9382dSDon Lewis steal->tdq_transferable == 0) { 198197e9382dSDon Lewis TDQ_UNLOCK(steal); 198297e9382dSDon Lewis break; 198397e9382dSDon Lewis } 198497e9382dSDon Lewis /* 198597e9382dSDon Lewis * If we fail to acquire one due to affinity restrictions, 198697e9382dSDon Lewis * bail out and let the idle thread to a more complete search 198797e9382dSDon Lewis * outside of a critical section. 198897e9382dSDon Lewis */ 198997e9382dSDon Lewis if (tdq_move(steal, tdq) == NULL) { 199097e9382dSDon Lewis TDQ_UNLOCK(steal); 199197e9382dSDon Lewis break; 199297e9382dSDon Lewis } 199397e9382dSDon Lewis TDQ_UNLOCK(steal); 199497e9382dSDon Lewis break; 199597e9382dSDon Lewis } 199697e9382dSDon Lewis spinlock_exit(); 199797e9382dSDon Lewis } 19984c8a8cfcSKonstantin Belousov #endif 199997e9382dSDon Lewis 200097e9382dSDon Lewis /* 2001c47f202bSJeff Roberson * Handle migration from sched_switch(). This happens only for 2002c47f202bSJeff Roberson * cpu binding. 2003c47f202bSJeff Roberson */ 2004c47f202bSJeff Roberson static struct mtx * 2005c47f202bSJeff Roberson sched_switch_migrate(struct tdq *tdq, struct thread *td, int flags) 2006c47f202bSJeff Roberson { 2007c47f202bSJeff Roberson struct tdq *tdn; 2008*61a74c5cSJeff Roberson struct mtx *mtx; 2009c47f202bSJeff Roberson 2010efe67753SNathan Whitehorn KASSERT(!CPU_ABSENT(td_get_sched(td)->ts_cpu), ("sched_switch_migrate: " 2011efe67753SNathan Whitehorn "thread %s queued on absent CPU %d.", td->td_name, 2012efe67753SNathan Whitehorn td_get_sched(td)->ts_cpu)); 201393ccd6bfSKonstantin Belousov tdn = TDQ_CPU(td_get_sched(td)->ts_cpu); 2014c47f202bSJeff Roberson #ifdef SMP 20159727e637SJeff Roberson tdq_load_rem(tdq, td); 2016c47f202bSJeff Roberson /* 2017c47f202bSJeff Roberson * Do the lock dance required to avoid LOR. We grab an extra 2018c47f202bSJeff Roberson * spinlock nesting to prevent preemption while we're 2019c47f202bSJeff Roberson * not holding either run-queue lock. 2020c47f202bSJeff Roberson */ 2021c47f202bSJeff Roberson spinlock_enter(); 2022*61a74c5cSJeff Roberson mtx = thread_lock_block(td); 2023*61a74c5cSJeff Roberson mtx_unlock_spin(mtx); 2024435068aaSAttilio Rao 2025435068aaSAttilio Rao /* 2026435068aaSAttilio Rao * Acquire both run-queue locks before placing the thread on the new 2027435068aaSAttilio Rao * run-queue to avoid deadlocks created by placing a thread with a 2028435068aaSAttilio Rao * blocked lock on the run-queue of a remote processor. The deadlock 2029435068aaSAttilio Rao * occurs when a third processor attempts to lock the two queues in 2030435068aaSAttilio Rao * question while the target processor is spinning with its own 2031435068aaSAttilio Rao * run-queue lock held while waiting for the blocked lock to clear. 2032435068aaSAttilio Rao */ 2033435068aaSAttilio Rao tdq_lock_pair(tdn, tdq); 2034c47f202bSJeff Roberson tdq_add(tdn, td, flags); 203527ee18adSRyan Stone tdq_notify(tdn, td); 2036c47f202bSJeff Roberson TDQ_UNLOCK(tdn); 2037c47f202bSJeff Roberson spinlock_exit(); 2038c47f202bSJeff Roberson #endif 2039c47f202bSJeff Roberson return (TDQ_LOCKPTR(tdn)); 2040c47f202bSJeff Roberson } 2041c47f202bSJeff Roberson 2042c47f202bSJeff Roberson /* 2043*61a74c5cSJeff Roberson * thread_lock_unblock() that does not assume td_lock is blocked. 2044ae7a6b38SJeff Roberson */ 2045ae7a6b38SJeff Roberson static inline void 2046ae7a6b38SJeff Roberson thread_unblock_switch(struct thread *td, struct mtx *mtx) 2047ae7a6b38SJeff Roberson { 2048ae7a6b38SJeff Roberson atomic_store_rel_ptr((volatile uintptr_t *)&td->td_lock, 2049ae7a6b38SJeff Roberson (uintptr_t)mtx); 2050ae7a6b38SJeff Roberson } 2051ae7a6b38SJeff Roberson 2052ae7a6b38SJeff Roberson /* 2053ae7a6b38SJeff Roberson * Switch threads. This function has to handle threads coming in while 2054ae7a6b38SJeff Roberson * blocked for some reason, running, or idle. It also must deal with 2055ae7a6b38SJeff Roberson * migrating a thread from one queue to another as running threads may 2056ae7a6b38SJeff Roberson * be assigned elsewhere via binding. 2057ae7a6b38SJeff Roberson */ 20583db720fdSDavid Xu void 20593389af30SJulian Elischer sched_switch(struct thread *td, struct thread *newtd, int flags) 206035e6168fSJeff Roberson { 2061c02bbb43SJeff Roberson struct tdq *tdq; 2062ad1e7d28SJulian Elischer struct td_sched *ts; 2063ae7a6b38SJeff Roberson struct mtx *mtx; 2064c47f202bSJeff Roberson int srqflag; 20653d7f4117SAlexander Motin int cpuid, preempted; 206635e6168fSJeff Roberson 20677b20fb19SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 20686d55b3ecSJeff Roberson KASSERT(newtd == NULL, ("sched_switch: Unsupported newtd argument")); 206935e6168fSJeff Roberson 2070ae7a6b38SJeff Roberson cpuid = PCPU_GET(cpuid); 2071018ff686SJeff Roberson tdq = TDQ_SELF(); 207293ccd6bfSKonstantin Belousov ts = td_get_sched(td); 2073c47f202bSJeff Roberson mtx = td->td_lock; 20747295465eSAlexander Motin sched_pctcpu_update(ts, 1); 2075ae7a6b38SJeff Roberson ts->ts_rltick = ticks; 2076060563ecSJulian Elischer td->td_lastcpu = td->td_oncpu; 2077060563ecSJulian Elischer td->td_oncpu = NOCPU; 2078ad9dadc4SAndriy Gapon preempted = (td->td_flags & TDF_SLICEEND) == 0 && 2079ad9dadc4SAndriy Gapon (flags & SW_PREEMPT) != 0; 20803d7f4117SAlexander Motin td->td_flags &= ~(TDF_NEEDRESCHED | TDF_SLICEEND); 208177918643SStephan Uphoff td->td_owepreempt = 0; 20827789ab32SMark Johnston tdq->tdq_owepreempt = 0; 20832c27cb3aSAlexander Motin if (!TD_IS_IDLETHREAD(td)) 20841690c6c1SJeff Roberson tdq->tdq_switchcnt++; 20857789ab32SMark Johnston 2086b11fdad0SJeff Roberson /* 2087ae7a6b38SJeff Roberson * The lock pointer in an idle thread should never change. Reset it 2088ae7a6b38SJeff Roberson * to CAN_RUN as well. 2089b11fdad0SJeff Roberson */ 2090486a9414SJulian Elischer if (TD_IS_IDLETHREAD(td)) { 2091ae7a6b38SJeff Roberson MPASS(td->td_lock == TDQ_LOCKPTR(tdq)); 2092bf0acc27SJohn Baldwin TD_SET_CAN_RUN(td); 20937b20fb19SJeff Roberson } else if (TD_IS_RUNNING(td)) { 2094ae7a6b38SJeff Roberson MPASS(td->td_lock == TDQ_LOCKPTR(tdq)); 20953d7f4117SAlexander Motin srqflag = preempted ? 2096598b368dSJeff Roberson SRQ_OURSELF|SRQ_YIELDING|SRQ_PREEMPTED : 2097c47f202bSJeff Roberson SRQ_OURSELF|SRQ_YIELDING; 2098ba4932b5SMatthew D Fleming #ifdef SMP 20990f7a0ebdSMatthew D Fleming if (THREAD_CAN_MIGRATE(td) && !THREAD_CAN_SCHED(td, ts->ts_cpu)) 21000f7a0ebdSMatthew D Fleming ts->ts_cpu = sched_pickcpu(td, 0); 2101ba4932b5SMatthew D Fleming #endif 2102c47f202bSJeff Roberson if (ts->ts_cpu == cpuid) 21039727e637SJeff Roberson tdq_runq_add(tdq, td, srqflag); 21040f7a0ebdSMatthew D Fleming else { 21050f7a0ebdSMatthew D Fleming KASSERT(THREAD_CAN_MIGRATE(td) || 21060f7a0ebdSMatthew D Fleming (ts->ts_flags & TSF_BOUND) != 0, 21070f7a0ebdSMatthew D Fleming ("Thread %p shouldn't migrate", td)); 2108c47f202bSJeff Roberson mtx = sched_switch_migrate(tdq, td, srqflag); 21090f7a0ebdSMatthew D Fleming } 2110ae7a6b38SJeff Roberson } else { 2111ae7a6b38SJeff Roberson /* This thread must be going to sleep. */ 2112b0b9dee5SAttilio Rao mtx = thread_lock_block(td); 2113*61a74c5cSJeff Roberson if (mtx != TDQ_LOCKPTR(tdq)) { 2114*61a74c5cSJeff Roberson spinlock_enter(); 2115*61a74c5cSJeff Roberson mtx_unlock_spin(mtx); 2116*61a74c5cSJeff Roberson TDQ_LOCK(tdq); 2117*61a74c5cSJeff Roberson spinlock_exit(); 2118*61a74c5cSJeff Roberson } 21199727e637SJeff Roberson tdq_load_rem(tdq, td); 21204c8a8cfcSKonstantin Belousov #ifdef SMP 212197e9382dSDon Lewis if (tdq->tdq_load == 0) 212297e9382dSDon Lewis tdq_trysteal(tdq); 21234c8a8cfcSKonstantin Belousov #endif 2124ae7a6b38SJeff Roberson } 2125afa0a46cSAndriy Gapon 2126afa0a46cSAndriy Gapon #if (KTR_COMPILE & KTR_SCHED) != 0 2127afa0a46cSAndriy Gapon if (TD_IS_IDLETHREAD(td)) 2128afa0a46cSAndriy Gapon KTR_STATE1(KTR_SCHED, "thread", sched_tdname(td), "idle", 2129afa0a46cSAndriy Gapon "prio:%d", td->td_priority); 2130afa0a46cSAndriy Gapon else 2131afa0a46cSAndriy Gapon KTR_STATE3(KTR_SCHED, "thread", sched_tdname(td), KTDSTATE(td), 2132afa0a46cSAndriy Gapon "prio:%d", td->td_priority, "wmesg:\"%s\"", td->td_wmesg, 2133afa0a46cSAndriy Gapon "lockname:\"%s\"", td->td_lockname); 2134afa0a46cSAndriy Gapon #endif 2135afa0a46cSAndriy Gapon 2136ae7a6b38SJeff Roberson /* 2137ae7a6b38SJeff Roberson * We enter here with the thread blocked and assigned to the 2138ae7a6b38SJeff Roberson * appropriate cpu run-queue or sleep-queue and with the current 2139ae7a6b38SJeff Roberson * thread-queue locked. 2140ae7a6b38SJeff Roberson */ 2141ae7a6b38SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED | MA_NOTRECURSED); 21422454aaf5SJeff Roberson newtd = choosethread(); 2143ae7a6b38SJeff Roberson /* 2144ae7a6b38SJeff Roberson * Call the MD code to switch contexts if necessary. 2145ae7a6b38SJeff Roberson */ 2146ebccf1e3SJoseph Koshy if (td != newtd) { 2147ebccf1e3SJoseph Koshy #ifdef HWPMC_HOOKS 2148ebccf1e3SJoseph Koshy if (PMC_PROC_IS_USING_PMCS(td->td_proc)) 2149ebccf1e3SJoseph Koshy PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_OUT); 2150ebccf1e3SJoseph Koshy #endif 2151d9fae5abSAndriy Gapon SDT_PROBE2(sched, , , off__cpu, newtd, newtd->td_proc); 2152eea4f254SJeff Roberson lock_profile_release_lock(&TDQ_LOCKPTR(tdq)->lock_object); 215359c68134SJeff Roberson TDQ_LOCKPTR(tdq)->mtx_lock = (uintptr_t)newtd; 215493ccd6bfSKonstantin Belousov sched_pctcpu_update(td_get_sched(newtd), 0); 21556f5f25e5SJohn Birrell 21566f5f25e5SJohn Birrell #ifdef KDTRACE_HOOKS 21576f5f25e5SJohn Birrell /* 21586f5f25e5SJohn Birrell * If DTrace has set the active vtime enum to anything 21596f5f25e5SJohn Birrell * other than INACTIVE (0), then it should have set the 21606f5f25e5SJohn Birrell * function to call. 21616f5f25e5SJohn Birrell */ 21626f5f25e5SJohn Birrell if (dtrace_vtime_active) 21636f5f25e5SJohn Birrell (*dtrace_vtime_switch_func)(newtd); 21646f5f25e5SJohn Birrell #endif 21656f5f25e5SJohn Birrell 2166ae7a6b38SJeff Roberson cpu_switch(td, newtd, mtx); 2167ae7a6b38SJeff Roberson /* 2168ae7a6b38SJeff Roberson * We may return from cpu_switch on a different cpu. However, 2169ae7a6b38SJeff Roberson * we always return with td_lock pointing to the current cpu's 2170ae7a6b38SJeff Roberson * run queue lock. 2171ae7a6b38SJeff Roberson */ 2172ae7a6b38SJeff Roberson cpuid = PCPU_GET(cpuid); 2173018ff686SJeff Roberson tdq = TDQ_SELF(); 2174eea4f254SJeff Roberson lock_profile_obtain_lock_success( 2175eea4f254SJeff Roberson &TDQ_LOCKPTR(tdq)->lock_object, 0, 0, __FILE__, __LINE__); 2176b3e9e682SRyan Stone 2177d9fae5abSAndriy Gapon SDT_PROBE0(sched, , , on__cpu); 2178ebccf1e3SJoseph Koshy #ifdef HWPMC_HOOKS 2179ebccf1e3SJoseph Koshy if (PMC_PROC_IS_USING_PMCS(td->td_proc)) 2180ebccf1e3SJoseph Koshy PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_IN); 2181ebccf1e3SJoseph Koshy #endif 2182b3e9e682SRyan Stone } else { 2183ae7a6b38SJeff Roberson thread_unblock_switch(td, mtx); 2184d9fae5abSAndriy Gapon SDT_PROBE0(sched, , , remain__cpu); 2185b3e9e682SRyan Stone } 2186afa0a46cSAndriy Gapon 2187afa0a46cSAndriy Gapon KTR_STATE1(KTR_SCHED, "thread", sched_tdname(td), "running", 2188afa0a46cSAndriy Gapon "prio:%d", td->td_priority); 2189afa0a46cSAndriy Gapon 2190ae7a6b38SJeff Roberson /* 2191ae7a6b38SJeff Roberson * Assert that all went well and return. 2192ae7a6b38SJeff Roberson */ 2193ae7a6b38SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED|MA_NOTRECURSED); 2194ae7a6b38SJeff Roberson MPASS(td->td_lock == TDQ_LOCKPTR(tdq)); 2195ae7a6b38SJeff Roberson td->td_oncpu = cpuid; 219635e6168fSJeff Roberson } 219735e6168fSJeff Roberson 2198ae7a6b38SJeff Roberson /* 2199ae7a6b38SJeff Roberson * Adjust thread priorities as a result of a nice request. 2200ae7a6b38SJeff Roberson */ 220135e6168fSJeff Roberson void 2202fa885116SJulian Elischer sched_nice(struct proc *p, int nice) 220335e6168fSJeff Roberson { 220435e6168fSJeff Roberson struct thread *td; 220535e6168fSJeff Roberson 2206fa885116SJulian Elischer PROC_LOCK_ASSERT(p, MA_OWNED); 2207e7d50326SJeff Roberson 2208fa885116SJulian Elischer p->p_nice = nice; 22098460a577SJohn Birrell FOREACH_THREAD_IN_PROC(p, td) { 22107b20fb19SJeff Roberson thread_lock(td); 22118460a577SJohn Birrell sched_priority(td); 2212e7d50326SJeff Roberson sched_prio(td, td->td_base_user_pri); 22137b20fb19SJeff Roberson thread_unlock(td); 221435e6168fSJeff Roberson } 2215fa885116SJulian Elischer } 221635e6168fSJeff Roberson 2217ae7a6b38SJeff Roberson /* 2218ae7a6b38SJeff Roberson * Record the sleep time for the interactivity scorer. 2219ae7a6b38SJeff Roberson */ 222035e6168fSJeff Roberson void 2221c5aa6b58SJeff Roberson sched_sleep(struct thread *td, int prio) 222235e6168fSJeff Roberson { 2223e7d50326SJeff Roberson 22247b20fb19SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 222535e6168fSJeff Roberson 222654b0e65fSJeff Roberson td->td_slptick = ticks; 222717c4c356SKonstantin Belousov if (TD_IS_SUSPENDED(td) || prio >= PSOCK) 2228c5aa6b58SJeff Roberson td->td_flags |= TDF_CANSWAP; 22292dc29adbSJohn Baldwin if (PRI_BASE(td->td_pri_class) != PRI_TIMESHARE) 22302dc29adbSJohn Baldwin return; 22310502fe2eSJeff Roberson if (static_boost == 1 && prio) 2232c5aa6b58SJeff Roberson sched_prio(td, prio); 22330502fe2eSJeff Roberson else if (static_boost && td->td_priority > static_boost) 22340502fe2eSJeff Roberson sched_prio(td, static_boost); 223535e6168fSJeff Roberson } 223635e6168fSJeff Roberson 2237ae7a6b38SJeff Roberson /* 2238ae7a6b38SJeff Roberson * Schedule a thread to resume execution and record how long it voluntarily 2239ae7a6b38SJeff Roberson * slept. We also update the pctcpu, interactivity, and priority. 2240*61a74c5cSJeff Roberson * 2241*61a74c5cSJeff Roberson * Requires the thread lock on entry, drops on exit. 2242ae7a6b38SJeff Roberson */ 224335e6168fSJeff Roberson void 2244*61a74c5cSJeff Roberson sched_wakeup(struct thread *td, int srqflags) 224535e6168fSJeff Roberson { 224614618990SJeff Roberson struct td_sched *ts; 2247ae7a6b38SJeff Roberson int slptick; 2248e7d50326SJeff Roberson 22497b20fb19SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 225093ccd6bfSKonstantin Belousov ts = td_get_sched(td); 2251c5aa6b58SJeff Roberson td->td_flags &= ~TDF_CANSWAP; 2252*61a74c5cSJeff Roberson 225335e6168fSJeff Roberson /* 2254e7d50326SJeff Roberson * If we slept for more than a tick update our interactivity and 2255e7d50326SJeff Roberson * priority. 225635e6168fSJeff Roberson */ 225754b0e65fSJeff Roberson slptick = td->td_slptick; 225854b0e65fSJeff Roberson td->td_slptick = 0; 2259ae7a6b38SJeff Roberson if (slptick && slptick != ticks) { 22607295465eSAlexander Motin ts->ts_slptime += (ticks - slptick) << SCHED_TICK_SHIFT; 22618460a577SJohn Birrell sched_interact_update(td); 22627295465eSAlexander Motin sched_pctcpu_update(ts, 0); 2263f1e8dc4aSJeff Roberson } 22645e5c3873SJeff Roberson /* 22655e5c3873SJeff Roberson * Reset the slice value since we slept and advanced the round-robin. 22665e5c3873SJeff Roberson */ 22675e5c3873SJeff Roberson ts->ts_slice = 0; 2268*61a74c5cSJeff Roberson sched_add(td, SRQ_BORING | srqflags); 226935e6168fSJeff Roberson } 227035e6168fSJeff Roberson 227135e6168fSJeff Roberson /* 227235e6168fSJeff Roberson * Penalize the parent for creating a new child and initialize the child's 227335e6168fSJeff Roberson * priority. 227435e6168fSJeff Roberson */ 227535e6168fSJeff Roberson void 22768460a577SJohn Birrell sched_fork(struct thread *td, struct thread *child) 227715dc847eSJeff Roberson { 22787b20fb19SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 227993ccd6bfSKonstantin Belousov sched_pctcpu_update(td_get_sched(td), 1); 2280ad1e7d28SJulian Elischer sched_fork_thread(td, child); 2281e7d50326SJeff Roberson /* 2282e7d50326SJeff Roberson * Penalize the parent and child for forking. 2283e7d50326SJeff Roberson */ 2284e7d50326SJeff Roberson sched_interact_fork(child); 2285e7d50326SJeff Roberson sched_priority(child); 228693ccd6bfSKonstantin Belousov td_get_sched(td)->ts_runtime += tickincr; 2287e7d50326SJeff Roberson sched_interact_update(td); 2288e7d50326SJeff Roberson sched_priority(td); 2289ad1e7d28SJulian Elischer } 2290ad1e7d28SJulian Elischer 2291ae7a6b38SJeff Roberson /* 2292ae7a6b38SJeff Roberson * Fork a new thread, may be within the same process. 2293ae7a6b38SJeff Roberson */ 2294ad1e7d28SJulian Elischer void 2295ad1e7d28SJulian Elischer sched_fork_thread(struct thread *td, struct thread *child) 2296ad1e7d28SJulian Elischer { 2297ad1e7d28SJulian Elischer struct td_sched *ts; 2298ad1e7d28SJulian Elischer struct td_sched *ts2; 22995e5c3873SJeff Roberson struct tdq *tdq; 23008460a577SJohn Birrell 23015e5c3873SJeff Roberson tdq = TDQ_SELF(); 23028b16c208SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 2303e7d50326SJeff Roberson /* 2304e7d50326SJeff Roberson * Initialize child. 2305e7d50326SJeff Roberson */ 230693ccd6bfSKonstantin Belousov ts = td_get_sched(td); 230793ccd6bfSKonstantin Belousov ts2 = td_get_sched(child); 230892de34dfSJohn Baldwin child->td_oncpu = NOCPU; 230992de34dfSJohn Baldwin child->td_lastcpu = NOCPU; 23105e5c3873SJeff Roberson child->td_lock = TDQ_LOCKPTR(tdq); 23118b16c208SJeff Roberson child->td_cpuset = cpuset_ref(td->td_cpuset); 23123f289c3fSJeff Roberson child->td_domain.dr_policy = td->td_cpuset->cs_domain; 2313ad1e7d28SJulian Elischer ts2->ts_cpu = ts->ts_cpu; 23148b16c208SJeff Roberson ts2->ts_flags = 0; 2315e7d50326SJeff Roberson /* 231622d19207SJohn Baldwin * Grab our parents cpu estimation information. 2317e7d50326SJeff Roberson */ 2318ad1e7d28SJulian Elischer ts2->ts_ticks = ts->ts_ticks; 2319ad1e7d28SJulian Elischer ts2->ts_ltick = ts->ts_ltick; 2320ad1e7d28SJulian Elischer ts2->ts_ftick = ts->ts_ftick; 232122d19207SJohn Baldwin /* 232222d19207SJohn Baldwin * Do not inherit any borrowed priority from the parent. 232322d19207SJohn Baldwin */ 232422d19207SJohn Baldwin child->td_priority = child->td_base_pri; 2325e7d50326SJeff Roberson /* 2326e7d50326SJeff Roberson * And update interactivity score. 2327e7d50326SJeff Roberson */ 2328ae7a6b38SJeff Roberson ts2->ts_slptime = ts->ts_slptime; 2329ae7a6b38SJeff Roberson ts2->ts_runtime = ts->ts_runtime; 23305e5c3873SJeff Roberson /* Attempt to quickly learn interactivity. */ 23315e5c3873SJeff Roberson ts2->ts_slice = tdq_slice(tdq) - sched_slice_min; 23328f51ad55SJeff Roberson #ifdef KTR 23338f51ad55SJeff Roberson bzero(ts2->ts_name, sizeof(ts2->ts_name)); 23348f51ad55SJeff Roberson #endif 233515dc847eSJeff Roberson } 233615dc847eSJeff Roberson 2337ae7a6b38SJeff Roberson /* 2338ae7a6b38SJeff Roberson * Adjust the priority class of a thread. 2339ae7a6b38SJeff Roberson */ 234015dc847eSJeff Roberson void 23418460a577SJohn Birrell sched_class(struct thread *td, int class) 234215dc847eSJeff Roberson { 234315dc847eSJeff Roberson 23447b20fb19SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 23458460a577SJohn Birrell if (td->td_pri_class == class) 234615dc847eSJeff Roberson return; 23478460a577SJohn Birrell td->td_pri_class = class; 234835e6168fSJeff Roberson } 234935e6168fSJeff Roberson 235035e6168fSJeff Roberson /* 235135e6168fSJeff Roberson * Return some of the child's priority and interactivity to the parent. 235235e6168fSJeff Roberson */ 235335e6168fSJeff Roberson void 2354fc6c30f6SJulian Elischer sched_exit(struct proc *p, struct thread *child) 235535e6168fSJeff Roberson { 2356e7d50326SJeff Roberson struct thread *td; 2357141ad61cSJeff Roberson 23588f51ad55SJeff Roberson KTR_STATE1(KTR_SCHED, "thread", sched_tdname(child), "proc exit", 2359cd39bb09SXin LI "prio:%d", child->td_priority); 2360374ae2a3SJeff Roberson PROC_LOCK_ASSERT(p, MA_OWNED); 2361e7d50326SJeff Roberson td = FIRST_THREAD_IN_PROC(p); 2362e7d50326SJeff Roberson sched_exit_thread(td, child); 2363ad1e7d28SJulian Elischer } 2364ad1e7d28SJulian Elischer 2365ae7a6b38SJeff Roberson /* 2366ae7a6b38SJeff Roberson * Penalize another thread for the time spent on this one. This helps to 2367ae7a6b38SJeff Roberson * worsen the priority and interactivity of processes which schedule batch 2368ae7a6b38SJeff Roberson * jobs such as make. This has little effect on the make process itself but 2369ae7a6b38SJeff Roberson * causes new processes spawned by it to receive worse scores immediately. 2370ae7a6b38SJeff Roberson */ 2371ad1e7d28SJulian Elischer void 2372fc6c30f6SJulian Elischer sched_exit_thread(struct thread *td, struct thread *child) 2373ad1e7d28SJulian Elischer { 2374fc6c30f6SJulian Elischer 23758f51ad55SJeff Roberson KTR_STATE1(KTR_SCHED, "thread", sched_tdname(child), "thread exit", 2376cd39bb09SXin LI "prio:%d", child->td_priority); 2377e7d50326SJeff Roberson /* 2378e7d50326SJeff Roberson * Give the child's runtime to the parent without returning the 2379e7d50326SJeff Roberson * sleep time as a penalty to the parent. This causes shells that 2380e7d50326SJeff Roberson * launch expensive things to mark their children as expensive. 2381e7d50326SJeff Roberson */ 23827b20fb19SJeff Roberson thread_lock(td); 238393ccd6bfSKonstantin Belousov td_get_sched(td)->ts_runtime += td_get_sched(child)->ts_runtime; 2384fc6c30f6SJulian Elischer sched_interact_update(td); 2385e7d50326SJeff Roberson sched_priority(td); 23867b20fb19SJeff Roberson thread_unlock(td); 2387ad1e7d28SJulian Elischer } 2388ad1e7d28SJulian Elischer 2389ff256d9cSJeff Roberson void 2390ff256d9cSJeff Roberson sched_preempt(struct thread *td) 2391ff256d9cSJeff Roberson { 2392ff256d9cSJeff Roberson struct tdq *tdq; 2393ff256d9cSJeff Roberson 2394b3e9e682SRyan Stone SDT_PROBE2(sched, , , surrender, td, td->td_proc); 2395b3e9e682SRyan Stone 2396ff256d9cSJeff Roberson thread_lock(td); 2397ff256d9cSJeff Roberson tdq = TDQ_SELF(); 2398ff256d9cSJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED); 2399ff256d9cSJeff Roberson if (td->td_priority > tdq->tdq_lowpri) { 24008df78c41SJeff Roberson int flags; 24018df78c41SJeff Roberson 24028df78c41SJeff Roberson flags = SW_INVOL | SW_PREEMPT; 2403ff256d9cSJeff Roberson if (td->td_critnest > 1) 2404ff256d9cSJeff Roberson td->td_owepreempt = 1; 24058df78c41SJeff Roberson else if (TD_IS_IDLETHREAD(td)) 24068df78c41SJeff Roberson mi_switch(flags | SWT_REMOTEWAKEIDLE, NULL); 2407ff256d9cSJeff Roberson else 24088df78c41SJeff Roberson mi_switch(flags | SWT_REMOTEPREEMPT, NULL); 24097789ab32SMark Johnston } else { 24107789ab32SMark Johnston tdq->tdq_owepreempt = 0; 2411ff256d9cSJeff Roberson } 2412ff256d9cSJeff Roberson thread_unlock(td); 2413ff256d9cSJeff Roberson } 2414ff256d9cSJeff Roberson 2415ae7a6b38SJeff Roberson /* 2416ae7a6b38SJeff Roberson * Fix priorities on return to user-space. Priorities may be elevated due 2417ae7a6b38SJeff Roberson * to static priorities in msleep() or similar. 2418ae7a6b38SJeff Roberson */ 2419ad1e7d28SJulian Elischer void 242028240885SMateusz Guzik sched_userret_slowpath(struct thread *td) 2421ad1e7d28SJulian Elischer { 242228240885SMateusz Guzik 24237b20fb19SJeff Roberson thread_lock(td); 2424ad1e7d28SJulian Elischer td->td_priority = td->td_user_pri; 2425ad1e7d28SJulian Elischer td->td_base_pri = td->td_user_pri; 242662fa74d9SJeff Roberson tdq_setlowpri(TDQ_SELF(), td); 24277b20fb19SJeff Roberson thread_unlock(td); 2428ad1e7d28SJulian Elischer } 242935e6168fSJeff Roberson 2430ae7a6b38SJeff Roberson /* 2431ae7a6b38SJeff Roberson * Handle a stathz tick. This is really only relevant for timeshare 2432ae7a6b38SJeff Roberson * threads. 2433ae7a6b38SJeff Roberson */ 243435e6168fSJeff Roberson void 2435c3cccf95SJeff Roberson sched_clock(struct thread *td, int cnt) 243635e6168fSJeff Roberson { 2437ad1e7d28SJulian Elischer struct tdq *tdq; 2438ad1e7d28SJulian Elischer struct td_sched *ts; 243935e6168fSJeff Roberson 2440ae7a6b38SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 24413f872f85SJeff Roberson tdq = TDQ_SELF(); 24427fcf154aSJeff Roberson #ifdef SMP 24437fcf154aSJeff Roberson /* 24447fcf154aSJeff Roberson * We run the long term load balancer infrequently on the first cpu. 24457fcf154aSJeff Roberson */ 2446c3cccf95SJeff Roberson if (balance_tdq == tdq && smp_started != 0 && rebalance != 0 && 2447c3cccf95SJeff Roberson balance_ticks != 0) { 2448c3cccf95SJeff Roberson balance_ticks -= cnt; 2449c3cccf95SJeff Roberson if (balance_ticks <= 0) 24507fcf154aSJeff Roberson sched_balance(); 24517fcf154aSJeff Roberson } 24527fcf154aSJeff Roberson #endif 24533f872f85SJeff Roberson /* 24541690c6c1SJeff Roberson * Save the old switch count so we have a record of the last ticks 24551690c6c1SJeff Roberson * activity. Initialize the new switch count based on our load. 24561690c6c1SJeff Roberson * If there is some activity seed it to reflect that. 24571690c6c1SJeff Roberson */ 24581690c6c1SJeff Roberson tdq->tdq_oldswitchcnt = tdq->tdq_switchcnt; 24596c47aaaeSJeff Roberson tdq->tdq_switchcnt = tdq->tdq_load; 24601690c6c1SJeff Roberson /* 24613f872f85SJeff Roberson * Advance the insert index once for each tick to ensure that all 24623f872f85SJeff Roberson * threads get a chance to run. 24633f872f85SJeff Roberson */ 24643f872f85SJeff Roberson if (tdq->tdq_idx == tdq->tdq_ridx) { 24653f872f85SJeff Roberson tdq->tdq_idx = (tdq->tdq_idx + 1) % RQ_NQS; 24663f872f85SJeff Roberson if (TAILQ_EMPTY(&tdq->tdq_timeshare.rq_queues[tdq->tdq_ridx])) 24673f872f85SJeff Roberson tdq->tdq_ridx = tdq->tdq_idx; 24683f872f85SJeff Roberson } 246993ccd6bfSKonstantin Belousov ts = td_get_sched(td); 24707295465eSAlexander Motin sched_pctcpu_update(ts, 1); 2471c3cccf95SJeff Roberson if ((td->td_pri_class & PRI_FIFO_BIT) || TD_IS_IDLETHREAD(td)) 2472a8949de2SJeff Roberson return; 2473c3cccf95SJeff Roberson 2474c9a8cba4SJohn Baldwin if (PRI_BASE(td->td_pri_class) == PRI_TIMESHARE) { 2475a8949de2SJeff Roberson /* 2476fd0b8c78SJeff Roberson * We used a tick; charge it to the thread so 2477fd0b8c78SJeff Roberson * that we can compute our interactivity. 247815dc847eSJeff Roberson */ 2479c3cccf95SJeff Roberson td_get_sched(td)->ts_runtime += tickincr * cnt; 24808460a577SJohn Birrell sched_interact_update(td); 248173daf66fSJeff Roberson sched_priority(td); 2482fd0b8c78SJeff Roberson } 2483579895dfSAlexander Motin 248435e6168fSJeff Roberson /* 2485579895dfSAlexander Motin * Force a context switch if the current thread has used up a full 2486579895dfSAlexander Motin * time slice (default is 100ms). 248735e6168fSJeff Roberson */ 2488c3cccf95SJeff Roberson ts->ts_slice += cnt; 2489c3cccf95SJeff Roberson if (ts->ts_slice >= tdq_slice(tdq)) { 24905e5c3873SJeff Roberson ts->ts_slice = 0; 24913d7f4117SAlexander Motin td->td_flags |= TDF_NEEDRESCHED | TDF_SLICEEND; 249235e6168fSJeff Roberson } 2493579895dfSAlexander Motin } 249435e6168fSJeff Roberson 2495ccd0ec40SKonstantin Belousov u_int 2496ccd0ec40SKonstantin Belousov sched_estcpu(struct thread *td __unused) 2497ae7a6b38SJeff Roberson { 2498ae7a6b38SJeff Roberson 2499ccd0ec40SKonstantin Belousov return (0); 2500ae7a6b38SJeff Roberson } 2501ae7a6b38SJeff Roberson 2502ae7a6b38SJeff Roberson /* 2503ae7a6b38SJeff Roberson * Return whether the current CPU has runnable tasks. Used for in-kernel 2504ae7a6b38SJeff Roberson * cooperative idle threads. 2505ae7a6b38SJeff Roberson */ 250635e6168fSJeff Roberson int 250735e6168fSJeff Roberson sched_runnable(void) 250835e6168fSJeff Roberson { 2509ad1e7d28SJulian Elischer struct tdq *tdq; 2510b90816f1SJeff Roberson int load; 251135e6168fSJeff Roberson 2512b90816f1SJeff Roberson load = 1; 2513b90816f1SJeff Roberson 2514ad1e7d28SJulian Elischer tdq = TDQ_SELF(); 25153f741ca1SJeff Roberson if ((curthread->td_flags & TDF_IDLETD) != 0) { 2516d2ad694cSJeff Roberson if (tdq->tdq_load > 0) 25173f741ca1SJeff Roberson goto out; 25183f741ca1SJeff Roberson } else 2519d2ad694cSJeff Roberson if (tdq->tdq_load - 1 > 0) 2520b90816f1SJeff Roberson goto out; 2521b90816f1SJeff Roberson load = 0; 2522b90816f1SJeff Roberson out: 2523b90816f1SJeff Roberson return (load); 252435e6168fSJeff Roberson } 252535e6168fSJeff Roberson 2526ae7a6b38SJeff Roberson /* 2527ae7a6b38SJeff Roberson * Choose the highest priority thread to run. The thread is removed from 2528ae7a6b38SJeff Roberson * the run-queue while running however the load remains. For SMP we set 2529ae7a6b38SJeff Roberson * the tdq in the global idle bitmask if it idles here. 2530ae7a6b38SJeff Roberson */ 25317a5e5e2aSJeff Roberson struct thread * 2532c9f25d8fSJeff Roberson sched_choose(void) 2533c9f25d8fSJeff Roberson { 25349727e637SJeff Roberson struct thread *td; 2535ae7a6b38SJeff Roberson struct tdq *tdq; 2536ae7a6b38SJeff Roberson 2537ae7a6b38SJeff Roberson tdq = TDQ_SELF(); 2538ae7a6b38SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED); 25399727e637SJeff Roberson td = tdq_choose(tdq); 25409727e637SJeff Roberson if (td) { 25419727e637SJeff Roberson tdq_runq_rem(tdq, td); 25420502fe2eSJeff Roberson tdq->tdq_lowpri = td->td_priority; 25439727e637SJeff Roberson return (td); 254435e6168fSJeff Roberson } 25450502fe2eSJeff Roberson tdq->tdq_lowpri = PRI_MAX_IDLE; 254662fa74d9SJeff Roberson return (PCPU_GET(idlethread)); 25477a5e5e2aSJeff Roberson } 25487a5e5e2aSJeff Roberson 2549ae7a6b38SJeff Roberson /* 2550ae7a6b38SJeff Roberson * Set owepreempt if necessary. Preemption never happens directly in ULE, 2551ae7a6b38SJeff Roberson * we always request it once we exit a critical section. 2552ae7a6b38SJeff Roberson */ 2553ae7a6b38SJeff Roberson static inline void 2554ae7a6b38SJeff Roberson sched_setpreempt(struct thread *td) 25557a5e5e2aSJeff Roberson { 25567a5e5e2aSJeff Roberson struct thread *ctd; 25577a5e5e2aSJeff Roberson int cpri; 25587a5e5e2aSJeff Roberson int pri; 25597a5e5e2aSJeff Roberson 2560ff256d9cSJeff Roberson THREAD_LOCK_ASSERT(curthread, MA_OWNED); 2561ff256d9cSJeff Roberson 25627a5e5e2aSJeff Roberson ctd = curthread; 25637a5e5e2aSJeff Roberson pri = td->td_priority; 25647a5e5e2aSJeff Roberson cpri = ctd->td_priority; 2565ff256d9cSJeff Roberson if (pri < cpri) 2566ff256d9cSJeff Roberson ctd->td_flags |= TDF_NEEDRESCHED; 25677a5e5e2aSJeff Roberson if (panicstr != NULL || pri >= cpri || cold || TD_IS_INHIBITED(ctd)) 2568ae7a6b38SJeff Roberson return; 2569ff256d9cSJeff Roberson if (!sched_shouldpreempt(pri, cpri, 0)) 2570ae7a6b38SJeff Roberson return; 25717a5e5e2aSJeff Roberson ctd->td_owepreempt = 1; 257235e6168fSJeff Roberson } 257335e6168fSJeff Roberson 2574ae7a6b38SJeff Roberson /* 257573daf66fSJeff Roberson * Add a thread to a thread queue. Select the appropriate runq and add the 257673daf66fSJeff Roberson * thread to it. This is the internal function called when the tdq is 257773daf66fSJeff Roberson * predetermined. 2578ae7a6b38SJeff Roberson */ 257935e6168fSJeff Roberson void 2580ae7a6b38SJeff Roberson tdq_add(struct tdq *tdq, struct thread *td, int flags) 258135e6168fSJeff Roberson { 2582c9f25d8fSJeff Roberson 2583ae7a6b38SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED); 2584*61a74c5cSJeff Roberson THREAD_LOCK_BLOCKED_ASSERT(td, MA_OWNED); 25857a5e5e2aSJeff Roberson KASSERT((td->td_inhibitors == 0), 25867a5e5e2aSJeff Roberson ("sched_add: trying to run inhibited thread")); 25877a5e5e2aSJeff Roberson KASSERT((TD_CAN_RUN(td) || TD_IS_RUNNING(td)), 25887a5e5e2aSJeff Roberson ("sched_add: bad thread state")); 2589b61ce5b0SJeff Roberson KASSERT(td->td_flags & TDF_INMEM, 2590b61ce5b0SJeff Roberson ("sched_add: thread swapped out")); 2591ae7a6b38SJeff Roberson 2592ae7a6b38SJeff Roberson if (td->td_priority < tdq->tdq_lowpri) 2593ae7a6b38SJeff Roberson tdq->tdq_lowpri = td->td_priority; 25949727e637SJeff Roberson tdq_runq_add(tdq, td, flags); 25959727e637SJeff Roberson tdq_load_add(tdq, td); 2596ae7a6b38SJeff Roberson } 2597ae7a6b38SJeff Roberson 2598ae7a6b38SJeff Roberson /* 2599ae7a6b38SJeff Roberson * Select the target thread queue and add a thread to it. Request 2600ae7a6b38SJeff Roberson * preemption or IPI a remote processor if required. 2601*61a74c5cSJeff Roberson * 2602*61a74c5cSJeff Roberson * Requires the thread lock on entry, drops on exit. 2603ae7a6b38SJeff Roberson */ 2604ae7a6b38SJeff Roberson void 2605ae7a6b38SJeff Roberson sched_add(struct thread *td, int flags) 2606ae7a6b38SJeff Roberson { 2607ae7a6b38SJeff Roberson struct tdq *tdq; 26087b8bfa0dSJeff Roberson #ifdef SMP 2609ae7a6b38SJeff Roberson int cpu; 2610ae7a6b38SJeff Roberson #endif 26118f51ad55SJeff Roberson 26128f51ad55SJeff Roberson KTR_STATE2(KTR_SCHED, "thread", sched_tdname(td), "runq add", 26138f51ad55SJeff Roberson "prio:%d", td->td_priority, KTR_ATTR_LINKED, 26148f51ad55SJeff Roberson sched_tdname(curthread)); 26158f51ad55SJeff Roberson KTR_POINT1(KTR_SCHED, "thread", sched_tdname(curthread), "wokeup", 26168f51ad55SJeff Roberson KTR_ATTR_LINKED, sched_tdname(td)); 2617b3e9e682SRyan Stone SDT_PROBE4(sched, , , enqueue, td, td->td_proc, NULL, 2618b3e9e682SRyan Stone flags & SRQ_PREEMPTED); 2619ae7a6b38SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 2620ae7a6b38SJeff Roberson /* 2621ae7a6b38SJeff Roberson * Recalculate the priority before we select the target cpu or 2622ae7a6b38SJeff Roberson * run-queue. 2623ae7a6b38SJeff Roberson */ 2624ae7a6b38SJeff Roberson if (PRI_BASE(td->td_pri_class) == PRI_TIMESHARE) 2625ae7a6b38SJeff Roberson sched_priority(td); 2626ae7a6b38SJeff Roberson #ifdef SMP 2627ae7a6b38SJeff Roberson /* 2628ae7a6b38SJeff Roberson * Pick the destination cpu and if it isn't ours transfer to the 2629ae7a6b38SJeff Roberson * target cpu. 2630ae7a6b38SJeff Roberson */ 26319727e637SJeff Roberson cpu = sched_pickcpu(td, flags); 26329727e637SJeff Roberson tdq = sched_setcpu(td, cpu, flags); 2633ae7a6b38SJeff Roberson tdq_add(tdq, td, flags); 2634*61a74c5cSJeff Roberson if (cpu != PCPU_GET(cpuid)) 263527ee18adSRyan Stone tdq_notify(tdq, td); 2636*61a74c5cSJeff Roberson else if (!(flags & SRQ_YIELDING)) 2637*61a74c5cSJeff Roberson sched_setpreempt(td); 2638ae7a6b38SJeff Roberson #else 2639ae7a6b38SJeff Roberson tdq = TDQ_SELF(); 2640ae7a6b38SJeff Roberson TDQ_LOCK(tdq); 2641ae7a6b38SJeff Roberson /* 2642ae7a6b38SJeff Roberson * Now that the thread is moving to the run-queue, set the lock 2643ae7a6b38SJeff Roberson * to the scheduler's lock. 2644ae7a6b38SJeff Roberson */ 2645*61a74c5cSJeff Roberson if ((flags & SRQ_HOLD) != 0) 2646*61a74c5cSJeff Roberson td->td_lock = TDQ_LOCKPTR(tdq); 2647*61a74c5cSJeff Roberson else 2648ae7a6b38SJeff Roberson thread_lock_set(td, TDQ_LOCKPTR(tdq)); 2649ae7a6b38SJeff Roberson tdq_add(tdq, td, flags); 2650ae7a6b38SJeff Roberson if (!(flags & SRQ_YIELDING)) 2651ae7a6b38SJeff Roberson sched_setpreempt(td); 2652*61a74c5cSJeff Roberson #endif 2653*61a74c5cSJeff Roberson if (!(flags & SRQ_HOLDTD)) 2654*61a74c5cSJeff Roberson thread_unlock(td); 265535e6168fSJeff Roberson } 265635e6168fSJeff Roberson 2657ae7a6b38SJeff Roberson /* 2658ae7a6b38SJeff Roberson * Remove a thread from a run-queue without running it. This is used 2659ae7a6b38SJeff Roberson * when we're stealing a thread from a remote queue. Otherwise all threads 2660ae7a6b38SJeff Roberson * exit by calling sched_exit_thread() and sched_throw() themselves. 2661ae7a6b38SJeff Roberson */ 266235e6168fSJeff Roberson void 26637cf90fb3SJeff Roberson sched_rem(struct thread *td) 266435e6168fSJeff Roberson { 2665ad1e7d28SJulian Elischer struct tdq *tdq; 26667cf90fb3SJeff Roberson 26678f51ad55SJeff Roberson KTR_STATE1(KTR_SCHED, "thread", sched_tdname(td), "runq rem", 26688f51ad55SJeff Roberson "prio:%d", td->td_priority); 2669b3e9e682SRyan Stone SDT_PROBE3(sched, , , dequeue, td, td->td_proc, NULL); 267093ccd6bfSKonstantin Belousov tdq = TDQ_CPU(td_get_sched(td)->ts_cpu); 2671ae7a6b38SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED); 2672ae7a6b38SJeff Roberson MPASS(td->td_lock == TDQ_LOCKPTR(tdq)); 26737a5e5e2aSJeff Roberson KASSERT(TD_ON_RUNQ(td), 2674ad1e7d28SJulian Elischer ("sched_rem: thread not on run queue")); 26759727e637SJeff Roberson tdq_runq_rem(tdq, td); 26769727e637SJeff Roberson tdq_load_rem(tdq, td); 26777a5e5e2aSJeff Roberson TD_SET_CAN_RUN(td); 267862fa74d9SJeff Roberson if (td->td_priority == tdq->tdq_lowpri) 267962fa74d9SJeff Roberson tdq_setlowpri(tdq, NULL); 268035e6168fSJeff Roberson } 268135e6168fSJeff Roberson 2682ae7a6b38SJeff Roberson /* 2683ae7a6b38SJeff Roberson * Fetch cpu utilization information. Updates on demand. 2684ae7a6b38SJeff Roberson */ 268535e6168fSJeff Roberson fixpt_t 26867cf90fb3SJeff Roberson sched_pctcpu(struct thread *td) 268735e6168fSJeff Roberson { 268835e6168fSJeff Roberson fixpt_t pctcpu; 2689ad1e7d28SJulian Elischer struct td_sched *ts; 269035e6168fSJeff Roberson 269135e6168fSJeff Roberson pctcpu = 0; 269293ccd6bfSKonstantin Belousov ts = td_get_sched(td); 269335e6168fSJeff Roberson 26943da35a0aSJohn Baldwin THREAD_LOCK_ASSERT(td, MA_OWNED); 26957295465eSAlexander Motin sched_pctcpu_update(ts, TD_IS_RUNNING(td)); 2696ad1e7d28SJulian Elischer if (ts->ts_ticks) { 269735e6168fSJeff Roberson int rtick; 269835e6168fSJeff Roberson 269935e6168fSJeff Roberson /* How many rtick per second ? */ 2700e7d50326SJeff Roberson rtick = min(SCHED_TICK_HZ(ts) / SCHED_TICK_SECS, hz); 2701e7d50326SJeff Roberson pctcpu = (FSCALE * ((FSCALE * rtick)/hz)) >> FSHIFT; 270235e6168fSJeff Roberson } 270335e6168fSJeff Roberson 270435e6168fSJeff Roberson return (pctcpu); 270535e6168fSJeff Roberson } 270635e6168fSJeff Roberson 270762fa74d9SJeff Roberson /* 270862fa74d9SJeff Roberson * Enforce affinity settings for a thread. Called after adjustments to 270962fa74d9SJeff Roberson * cpumask. 271062fa74d9SJeff Roberson */ 2711885d51a3SJeff Roberson void 2712885d51a3SJeff Roberson sched_affinity(struct thread *td) 2713885d51a3SJeff Roberson { 271462fa74d9SJeff Roberson #ifdef SMP 271562fa74d9SJeff Roberson struct td_sched *ts; 271662fa74d9SJeff Roberson 271762fa74d9SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 271893ccd6bfSKonstantin Belousov ts = td_get_sched(td); 271962fa74d9SJeff Roberson if (THREAD_CAN_SCHED(td, ts->ts_cpu)) 272062fa74d9SJeff Roberson return; 272153a6c8b3SJeff Roberson if (TD_ON_RUNQ(td)) { 272253a6c8b3SJeff Roberson sched_rem(td); 272353a6c8b3SJeff Roberson sched_add(td, SRQ_BORING); 272453a6c8b3SJeff Roberson return; 272553a6c8b3SJeff Roberson } 272662fa74d9SJeff Roberson if (!TD_IS_RUNNING(td)) 272762fa74d9SJeff Roberson return; 272862fa74d9SJeff Roberson /* 27290f7a0ebdSMatthew D Fleming * Force a switch before returning to userspace. If the 27300f7a0ebdSMatthew D Fleming * target thread is not running locally send an ipi to force 27310f7a0ebdSMatthew D Fleming * the issue. 273262fa74d9SJeff Roberson */ 2733a8103ae8SJohn Baldwin td->td_flags |= TDF_NEEDRESCHED; 27340f7a0ebdSMatthew D Fleming if (td != curthread) 27350f7a0ebdSMatthew D Fleming ipi_cpu(ts->ts_cpu, IPI_PREEMPT); 273662fa74d9SJeff Roberson #endif 2737885d51a3SJeff Roberson } 2738885d51a3SJeff Roberson 2739ae7a6b38SJeff Roberson /* 2740ae7a6b38SJeff Roberson * Bind a thread to a target cpu. 2741ae7a6b38SJeff Roberson */ 27429bacd788SJeff Roberson void 27439bacd788SJeff Roberson sched_bind(struct thread *td, int cpu) 27449bacd788SJeff Roberson { 2745ad1e7d28SJulian Elischer struct td_sched *ts; 27469bacd788SJeff Roberson 2747c47f202bSJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED|MA_NOTRECURSED); 27481d7830edSJohn Baldwin KASSERT(td == curthread, ("sched_bind: can only bind curthread")); 274993ccd6bfSKonstantin Belousov ts = td_get_sched(td); 27506b2f763fSJeff Roberson if (ts->ts_flags & TSF_BOUND) 2751c95d2db2SJeff Roberson sched_unbind(td); 27520f7a0ebdSMatthew D Fleming KASSERT(THREAD_CAN_MIGRATE(td), ("%p must be migratable", td)); 2753ad1e7d28SJulian Elischer ts->ts_flags |= TSF_BOUND; 27546b2f763fSJeff Roberson sched_pin(); 275580f86c9fSJeff Roberson if (PCPU_GET(cpuid) == cpu) 27569bacd788SJeff Roberson return; 27576b2f763fSJeff Roberson ts->ts_cpu = cpu; 27589bacd788SJeff Roberson /* When we return from mi_switch we'll be on the correct cpu. */ 2759279f949eSPoul-Henning Kamp mi_switch(SW_VOL, NULL); 27609bacd788SJeff Roberson } 27619bacd788SJeff Roberson 2762ae7a6b38SJeff Roberson /* 2763ae7a6b38SJeff Roberson * Release a bound thread. 2764ae7a6b38SJeff Roberson */ 27659bacd788SJeff Roberson void 27669bacd788SJeff Roberson sched_unbind(struct thread *td) 27679bacd788SJeff Roberson { 2768e7d50326SJeff Roberson struct td_sched *ts; 2769e7d50326SJeff Roberson 27707b20fb19SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 27711d7830edSJohn Baldwin KASSERT(td == curthread, ("sched_unbind: can only bind curthread")); 277293ccd6bfSKonstantin Belousov ts = td_get_sched(td); 27736b2f763fSJeff Roberson if ((ts->ts_flags & TSF_BOUND) == 0) 27746b2f763fSJeff Roberson return; 2775e7d50326SJeff Roberson ts->ts_flags &= ~TSF_BOUND; 2776e7d50326SJeff Roberson sched_unpin(); 27779bacd788SJeff Roberson } 27789bacd788SJeff Roberson 277935e6168fSJeff Roberson int 2780ebccf1e3SJoseph Koshy sched_is_bound(struct thread *td) 2781ebccf1e3SJoseph Koshy { 27827b20fb19SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 278393ccd6bfSKonstantin Belousov return (td_get_sched(td)->ts_flags & TSF_BOUND); 2784ebccf1e3SJoseph Koshy } 2785ebccf1e3SJoseph Koshy 2786ae7a6b38SJeff Roberson /* 2787ae7a6b38SJeff Roberson * Basic yield call. 2788ae7a6b38SJeff Roberson */ 278936ec198bSDavid Xu void 279036ec198bSDavid Xu sched_relinquish(struct thread *td) 279136ec198bSDavid Xu { 27927b20fb19SJeff Roberson thread_lock(td); 27938df78c41SJeff Roberson mi_switch(SW_VOL | SWT_RELINQUISH, NULL); 27947b20fb19SJeff Roberson thread_unlock(td); 279536ec198bSDavid Xu } 279636ec198bSDavid Xu 2797ae7a6b38SJeff Roberson /* 2798ae7a6b38SJeff Roberson * Return the total system load. 2799ae7a6b38SJeff Roberson */ 2800ebccf1e3SJoseph Koshy int 280133916c36SJeff Roberson sched_load(void) 280233916c36SJeff Roberson { 280333916c36SJeff Roberson #ifdef SMP 280433916c36SJeff Roberson int total; 280533916c36SJeff Roberson int i; 280633916c36SJeff Roberson 280733916c36SJeff Roberson total = 0; 28083aa6d94eSJohn Baldwin CPU_FOREACH(i) 280962fa74d9SJeff Roberson total += TDQ_CPU(i)->tdq_sysload; 281033916c36SJeff Roberson return (total); 281133916c36SJeff Roberson #else 2812d2ad694cSJeff Roberson return (TDQ_SELF()->tdq_sysload); 281333916c36SJeff Roberson #endif 281433916c36SJeff Roberson } 281533916c36SJeff Roberson 281633916c36SJeff Roberson int 281735e6168fSJeff Roberson sched_sizeof_proc(void) 281835e6168fSJeff Roberson { 281935e6168fSJeff Roberson return (sizeof(struct proc)); 282035e6168fSJeff Roberson } 282135e6168fSJeff Roberson 282235e6168fSJeff Roberson int 282335e6168fSJeff Roberson sched_sizeof_thread(void) 282435e6168fSJeff Roberson { 282535e6168fSJeff Roberson return (sizeof(struct thread) + sizeof(struct td_sched)); 282635e6168fSJeff Roberson } 2827b41f1452SDavid Xu 282809c8a4ccSJeff Roberson #ifdef SMP 282909c8a4ccSJeff Roberson #define TDQ_IDLESPIN(tdq) \ 283009c8a4ccSJeff Roberson ((tdq)->tdq_cg != NULL && ((tdq)->tdq_cg->cg_flags & CG_FLAG_THREAD) == 0) 283109c8a4ccSJeff Roberson #else 283209c8a4ccSJeff Roberson #define TDQ_IDLESPIN(tdq) 1 283309c8a4ccSJeff Roberson #endif 283409c8a4ccSJeff Roberson 28357a5e5e2aSJeff Roberson /* 28367a5e5e2aSJeff Roberson * The actual idle process. 28377a5e5e2aSJeff Roberson */ 28387a5e5e2aSJeff Roberson void 28397a5e5e2aSJeff Roberson sched_idletd(void *dummy) 28407a5e5e2aSJeff Roberson { 28417a5e5e2aSJeff Roberson struct thread *td; 2842ae7a6b38SJeff Roberson struct tdq *tdq; 28432c27cb3aSAlexander Motin int oldswitchcnt, switchcnt; 28441690c6c1SJeff Roberson int i; 28457a5e5e2aSJeff Roberson 28467b55ab05SJeff Roberson mtx_assert(&Giant, MA_NOTOWNED); 28477a5e5e2aSJeff Roberson td = curthread; 2848ae7a6b38SJeff Roberson tdq = TDQ_SELF(); 2849ba96d2d8SJohn Baldwin THREAD_NO_SLEEPING(); 28502c27cb3aSAlexander Motin oldswitchcnt = -1; 2851ae7a6b38SJeff Roberson for (;;) { 28522c27cb3aSAlexander Motin if (tdq->tdq_load) { 28532c27cb3aSAlexander Motin thread_lock(td); 28542c27cb3aSAlexander Motin mi_switch(SW_VOL | SWT_IDLE, NULL); 28552c27cb3aSAlexander Motin thread_unlock(td); 28562c27cb3aSAlexander Motin } 28572c27cb3aSAlexander Motin switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt; 2858ae7a6b38SJeff Roberson #ifdef SMP 285997e9382dSDon Lewis if (always_steal || switchcnt != oldswitchcnt) { 28602c27cb3aSAlexander Motin oldswitchcnt = switchcnt; 28611690c6c1SJeff Roberson if (tdq_idled(tdq) == 0) 28621690c6c1SJeff Roberson continue; 28632c27cb3aSAlexander Motin } 28641690c6c1SJeff Roberson switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt; 28652fd4047fSAlexander Motin #else 28662fd4047fSAlexander Motin oldswitchcnt = switchcnt; 28672fd4047fSAlexander Motin #endif 28681690c6c1SJeff Roberson /* 28691690c6c1SJeff Roberson * If we're switching very frequently, spin while checking 28701690c6c1SJeff Roberson * for load rather than entering a low power state that 28717b55ab05SJeff Roberson * may require an IPI. However, don't do any busy 28727b55ab05SJeff Roberson * loops while on SMT machines as this simply steals 28737b55ab05SJeff Roberson * cycles from cores doing useful work. 28741690c6c1SJeff Roberson */ 287509c8a4ccSJeff Roberson if (TDQ_IDLESPIN(tdq) && switchcnt > sched_idlespinthresh) { 28761690c6c1SJeff Roberson for (i = 0; i < sched_idlespins; i++) { 28771690c6c1SJeff Roberson if (tdq->tdq_load) 28781690c6c1SJeff Roberson break; 28791690c6c1SJeff Roberson cpu_spinwait(); 28801690c6c1SJeff Roberson } 28811690c6c1SJeff Roberson } 28822c27cb3aSAlexander Motin 28832c27cb3aSAlexander Motin /* If there was context switch during spin, restart it. */ 28846c47aaaeSJeff Roberson switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt; 28852c27cb3aSAlexander Motin if (tdq->tdq_load != 0 || switchcnt != oldswitchcnt) 28862c27cb3aSAlexander Motin continue; 28872c27cb3aSAlexander Motin 28882c27cb3aSAlexander Motin /* Run main MD idle handler. */ 28899f9ad565SAlexander Motin tdq->tdq_cpu_idle = 1; 289079654969SAlexander Motin /* 289179654969SAlexander Motin * Make sure that tdq_cpu_idle update is globally visible 289279654969SAlexander Motin * before cpu_idle() read tdq_load. The order is important 289379654969SAlexander Motin * to avoid race with tdq_notify. 289479654969SAlexander Motin */ 2895e8677f38SKonstantin Belousov atomic_thread_fence_seq_cst(); 289697e9382dSDon Lewis /* 289797e9382dSDon Lewis * Checking for again after the fence picks up assigned 289897e9382dSDon Lewis * threads often enough to make it worthwhile to do so in 289997e9382dSDon Lewis * order to avoid calling cpu_idle(). 290097e9382dSDon Lewis */ 290197e9382dSDon Lewis if (tdq->tdq_load != 0) { 290297e9382dSDon Lewis tdq->tdq_cpu_idle = 0; 290397e9382dSDon Lewis continue; 290497e9382dSDon Lewis } 29052c27cb3aSAlexander Motin cpu_idle(switchcnt * 4 > sched_idlespinthresh); 29069f9ad565SAlexander Motin tdq->tdq_cpu_idle = 0; 29072c27cb3aSAlexander Motin 29082c27cb3aSAlexander Motin /* 29092c27cb3aSAlexander Motin * Account thread-less hardware interrupts and 29102c27cb3aSAlexander Motin * other wakeup reasons equal to context switches. 29112c27cb3aSAlexander Motin */ 29122c27cb3aSAlexander Motin switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt; 29132c27cb3aSAlexander Motin if (switchcnt != oldswitchcnt) 29142c27cb3aSAlexander Motin continue; 29152c27cb3aSAlexander Motin tdq->tdq_switchcnt++; 29162c27cb3aSAlexander Motin oldswitchcnt++; 2917ae7a6b38SJeff Roberson } 2918b41f1452SDavid Xu } 2919e7d50326SJeff Roberson 29207b20fb19SJeff Roberson /* 29217b20fb19SJeff Roberson * A CPU is entering for the first time or a thread is exiting. 29227b20fb19SJeff Roberson */ 29237b20fb19SJeff Roberson void 29247b20fb19SJeff Roberson sched_throw(struct thread *td) 29257b20fb19SJeff Roberson { 292659c68134SJeff Roberson struct thread *newtd; 2927ae7a6b38SJeff Roberson struct tdq *tdq; 2928ae7a6b38SJeff Roberson 29297b20fb19SJeff Roberson if (td == NULL) { 2930018ff686SJeff Roberson #ifdef SMP 2931018ff686SJeff Roberson PCPU_SET(sched, DPCPU_PTR(tdq)); 2932018ff686SJeff Roberson #endif 2933ae7a6b38SJeff Roberson /* Correct spinlock nesting and acquire the correct lock. */ 2934018ff686SJeff Roberson tdq = TDQ_SELF(); 2935ae7a6b38SJeff Roberson TDQ_LOCK(tdq); 29367b20fb19SJeff Roberson spinlock_exit(); 29377e3a96eaSJohn Baldwin PCPU_SET(switchtime, cpu_ticks()); 29387e3a96eaSJohn Baldwin PCPU_SET(switchticks, ticks); 2939e1504695SJeff Roberson PCPU_GET(idlethread)->td_lock = TDQ_LOCKPTR(tdq); 29407b20fb19SJeff Roberson } else { 2941*61a74c5cSJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 2942018ff686SJeff Roberson tdq = TDQ_SELF(); 2943ae7a6b38SJeff Roberson MPASS(td->td_lock == TDQ_LOCKPTR(tdq)); 29449727e637SJeff Roberson tdq_load_rem(tdq, td); 2945eea4f254SJeff Roberson lock_profile_release_lock(&TDQ_LOCKPTR(tdq)->lock_object); 294692de34dfSJohn Baldwin td->td_lastcpu = td->td_oncpu; 294792de34dfSJohn Baldwin td->td_oncpu = NOCPU; 29487b20fb19SJeff Roberson } 29497b20fb19SJeff Roberson KASSERT(curthread->td_md.md_spinlock_count == 1, ("invalid count")); 295059c68134SJeff Roberson newtd = choosethread(); 295159c68134SJeff Roberson TDQ_LOCKPTR(tdq)->mtx_lock = (uintptr_t)newtd; 295259c68134SJeff Roberson cpu_throw(td, newtd); /* doesn't return */ 29537b20fb19SJeff Roberson } 29547b20fb19SJeff Roberson 2955ae7a6b38SJeff Roberson /* 2956ae7a6b38SJeff Roberson * This is called from fork_exit(). Just acquire the correct locks and 2957ae7a6b38SJeff Roberson * let fork do the rest of the work. 2958ae7a6b38SJeff Roberson */ 29597b20fb19SJeff Roberson void 2960fe54587fSJeff Roberson sched_fork_exit(struct thread *td) 29617b20fb19SJeff Roberson { 2962ae7a6b38SJeff Roberson struct tdq *tdq; 2963ae7a6b38SJeff Roberson int cpuid; 29647b20fb19SJeff Roberson 29657b20fb19SJeff Roberson /* 29667b20fb19SJeff Roberson * Finish setting up thread glue so that it begins execution in a 2967ae7a6b38SJeff Roberson * non-nested critical section with the scheduler lock held. 29687b20fb19SJeff Roberson */ 2969ae7a6b38SJeff Roberson cpuid = PCPU_GET(cpuid); 2970018ff686SJeff Roberson tdq = TDQ_SELF(); 2971ae7a6b38SJeff Roberson MPASS(td->td_lock == TDQ_LOCKPTR(tdq)); 2972ae7a6b38SJeff Roberson td->td_oncpu = cpuid; 297359c68134SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED | MA_NOTRECURSED); 2974eea4f254SJeff Roberson lock_profile_obtain_lock_success( 2975eea4f254SJeff Roberson &TDQ_LOCKPTR(tdq)->lock_object, 0, 0, __FILE__, __LINE__); 297628ef18b8SAndriy Gapon 297728ef18b8SAndriy Gapon KTR_STATE1(KTR_SCHED, "thread", sched_tdname(td), "running", 297828ef18b8SAndriy Gapon "prio:%d", td->td_priority); 297928ef18b8SAndriy Gapon SDT_PROBE0(sched, , , on__cpu); 29807b20fb19SJeff Roberson } 29817b20fb19SJeff Roberson 29828f51ad55SJeff Roberson /* 29838f51ad55SJeff Roberson * Create on first use to catch odd startup conditons. 29848f51ad55SJeff Roberson */ 29858f51ad55SJeff Roberson char * 29868f51ad55SJeff Roberson sched_tdname(struct thread *td) 29878f51ad55SJeff Roberson { 29888f51ad55SJeff Roberson #ifdef KTR 29898f51ad55SJeff Roberson struct td_sched *ts; 29908f51ad55SJeff Roberson 299193ccd6bfSKonstantin Belousov ts = td_get_sched(td); 29928f51ad55SJeff Roberson if (ts->ts_name[0] == '\0') 29938f51ad55SJeff Roberson snprintf(ts->ts_name, sizeof(ts->ts_name), 29948f51ad55SJeff Roberson "%s tid %d", td->td_name, td->td_tid); 29958f51ad55SJeff Roberson return (ts->ts_name); 29968f51ad55SJeff Roberson #else 29978f51ad55SJeff Roberson return (td->td_name); 29988f51ad55SJeff Roberson #endif 29998f51ad55SJeff Roberson } 30008f51ad55SJeff Roberson 300144ad5475SJohn Baldwin #ifdef KTR 300244ad5475SJohn Baldwin void 300344ad5475SJohn Baldwin sched_clear_tdname(struct thread *td) 300444ad5475SJohn Baldwin { 300544ad5475SJohn Baldwin struct td_sched *ts; 300644ad5475SJohn Baldwin 300793ccd6bfSKonstantin Belousov ts = td_get_sched(td); 300844ad5475SJohn Baldwin ts->ts_name[0] = '\0'; 300944ad5475SJohn Baldwin } 301044ad5475SJohn Baldwin #endif 301144ad5475SJohn Baldwin 301207095abfSIvan Voras #ifdef SMP 301307095abfSIvan Voras 301407095abfSIvan Voras /* 301507095abfSIvan Voras * Build the CPU topology dump string. Is recursively called to collect 301607095abfSIvan Voras * the topology tree. 301707095abfSIvan Voras */ 301807095abfSIvan Voras static int 301907095abfSIvan Voras sysctl_kern_sched_topology_spec_internal(struct sbuf *sb, struct cpu_group *cg, 302007095abfSIvan Voras int indent) 302107095abfSIvan Voras { 302271a19bdcSAttilio Rao char cpusetbuf[CPUSETBUFSIZ]; 302307095abfSIvan Voras int i, first; 302407095abfSIvan Voras 302507095abfSIvan Voras sbuf_printf(sb, "%*s<group level=\"%d\" cache-level=\"%d\">\n", indent, 302619b8a6dbSAndriy Gapon "", 1 + indent / 2, cg->cg_level); 302771a19bdcSAttilio Rao sbuf_printf(sb, "%*s <cpu count=\"%d\" mask=\"%s\">", indent, "", 302871a19bdcSAttilio Rao cg->cg_count, cpusetobj_strprint(cpusetbuf, &cg->cg_mask)); 302907095abfSIvan Voras first = TRUE; 303007095abfSIvan Voras for (i = 0; i < MAXCPU; i++) { 303171a19bdcSAttilio Rao if (CPU_ISSET(i, &cg->cg_mask)) { 303207095abfSIvan Voras if (!first) 303307095abfSIvan Voras sbuf_printf(sb, ", "); 303407095abfSIvan Voras else 303507095abfSIvan Voras first = FALSE; 303607095abfSIvan Voras sbuf_printf(sb, "%d", i); 303707095abfSIvan Voras } 303807095abfSIvan Voras } 303907095abfSIvan Voras sbuf_printf(sb, "</cpu>\n"); 304007095abfSIvan Voras 304107095abfSIvan Voras if (cg->cg_flags != 0) { 3042611daf7eSIvan Voras sbuf_printf(sb, "%*s <flags>", indent, ""); 304307095abfSIvan Voras if ((cg->cg_flags & CG_FLAG_HTT) != 0) 30445368befbSIvan Voras sbuf_printf(sb, "<flag name=\"HTT\">HTT group</flag>"); 3045a401f2d0SIvan Voras if ((cg->cg_flags & CG_FLAG_THREAD) != 0) 3046a401f2d0SIvan Voras sbuf_printf(sb, "<flag name=\"THREAD\">THREAD group</flag>"); 30477b55ab05SJeff Roberson if ((cg->cg_flags & CG_FLAG_SMT) != 0) 3048a401f2d0SIvan Voras sbuf_printf(sb, "<flag name=\"SMT\">SMT group</flag>"); 304907095abfSIvan Voras sbuf_printf(sb, "</flags>\n"); 3050611daf7eSIvan Voras } 305107095abfSIvan Voras 305207095abfSIvan Voras if (cg->cg_children > 0) { 305307095abfSIvan Voras sbuf_printf(sb, "%*s <children>\n", indent, ""); 305407095abfSIvan Voras for (i = 0; i < cg->cg_children; i++) 305507095abfSIvan Voras sysctl_kern_sched_topology_spec_internal(sb, 305607095abfSIvan Voras &cg->cg_child[i], indent+2); 305707095abfSIvan Voras sbuf_printf(sb, "%*s </children>\n", indent, ""); 305807095abfSIvan Voras } 305907095abfSIvan Voras sbuf_printf(sb, "%*s</group>\n", indent, ""); 306007095abfSIvan Voras return (0); 306107095abfSIvan Voras } 306207095abfSIvan Voras 306307095abfSIvan Voras /* 306407095abfSIvan Voras * Sysctl handler for retrieving topology dump. It's a wrapper for 306507095abfSIvan Voras * the recursive sysctl_kern_smp_topology_spec_internal(). 306607095abfSIvan Voras */ 306707095abfSIvan Voras static int 306807095abfSIvan Voras sysctl_kern_sched_topology_spec(SYSCTL_HANDLER_ARGS) 306907095abfSIvan Voras { 307007095abfSIvan Voras struct sbuf *topo; 307107095abfSIvan Voras int err; 307207095abfSIvan Voras 307307095abfSIvan Voras KASSERT(cpu_top != NULL, ("cpu_top isn't initialized")); 307407095abfSIvan Voras 3075b97fa22cSIan Lepore topo = sbuf_new_for_sysctl(NULL, NULL, 512, req); 307607095abfSIvan Voras if (topo == NULL) 307707095abfSIvan Voras return (ENOMEM); 307807095abfSIvan Voras 307907095abfSIvan Voras sbuf_printf(topo, "<groups>\n"); 308007095abfSIvan Voras err = sysctl_kern_sched_topology_spec_internal(topo, cpu_top, 1); 308107095abfSIvan Voras sbuf_printf(topo, "</groups>\n"); 308207095abfSIvan Voras 308307095abfSIvan Voras if (err == 0) { 3084b97fa22cSIan Lepore err = sbuf_finish(topo); 308507095abfSIvan Voras } 308607095abfSIvan Voras sbuf_delete(topo); 308707095abfSIvan Voras return (err); 308807095abfSIvan Voras } 3089b67cc292SDavid Xu 309007095abfSIvan Voras #endif 309107095abfSIvan Voras 3092579895dfSAlexander Motin static int 3093579895dfSAlexander Motin sysctl_kern_quantum(SYSCTL_HANDLER_ARGS) 3094579895dfSAlexander Motin { 3095579895dfSAlexander Motin int error, new_val, period; 3096579895dfSAlexander Motin 3097579895dfSAlexander Motin period = 1000000 / realstathz; 3098579895dfSAlexander Motin new_val = period * sched_slice; 3099579895dfSAlexander Motin error = sysctl_handle_int(oidp, &new_val, 0, req); 3100579895dfSAlexander Motin if (error != 0 || req->newptr == NULL) 3101579895dfSAlexander Motin return (error); 3102579895dfSAlexander Motin if (new_val <= 0) 3103579895dfSAlexander Motin return (EINVAL); 310437f4e025SAlexander Motin sched_slice = imax(1, (new_val + period / 2) / period); 31055e5c3873SJeff Roberson sched_slice_min = sched_slice / SCHED_SLICE_MIN_DIVISOR; 310637f4e025SAlexander Motin hogticks = imax(1, (2 * hz * sched_slice + realstathz / 2) / 310737f4e025SAlexander Motin realstathz); 3108579895dfSAlexander Motin return (0); 3109579895dfSAlexander Motin } 3110579895dfSAlexander Motin 31119727e637SJeff Roberson SYSCTL_NODE(_kern, OID_AUTO, sched, CTLFLAG_RW, 0, "Scheduler"); 3112ae7a6b38SJeff Roberson SYSCTL_STRING(_kern_sched, OID_AUTO, name, CTLFLAG_RD, "ULE", 0, 3113e7d50326SJeff Roberson "Scheduler name"); 3114579895dfSAlexander Motin SYSCTL_PROC(_kern_sched, OID_AUTO, quantum, CTLTYPE_INT | CTLFLAG_RW, 3115579895dfSAlexander Motin NULL, 0, sysctl_kern_quantum, "I", 311637f4e025SAlexander Motin "Quantum for timeshare threads in microseconds"); 3117ae7a6b38SJeff Roberson SYSCTL_INT(_kern_sched, OID_AUTO, slice, CTLFLAG_RW, &sched_slice, 0, 311837f4e025SAlexander Motin "Quantum for timeshare threads in stathz ticks"); 3119ae7a6b38SJeff Roberson SYSCTL_INT(_kern_sched, OID_AUTO, interact, CTLFLAG_RW, &sched_interact, 0, 3120ae7a6b38SJeff Roberson "Interactivity score threshold"); 312137f4e025SAlexander Motin SYSCTL_INT(_kern_sched, OID_AUTO, preempt_thresh, CTLFLAG_RW, 312237f4e025SAlexander Motin &preempt_thresh, 0, 312337f4e025SAlexander Motin "Maximal (lowest) priority for preemption"); 312437f4e025SAlexander Motin SYSCTL_INT(_kern_sched, OID_AUTO, static_boost, CTLFLAG_RW, &static_boost, 0, 312537f4e025SAlexander Motin "Assign static kernel priorities to sleeping threads"); 312637f4e025SAlexander Motin SYSCTL_INT(_kern_sched, OID_AUTO, idlespins, CTLFLAG_RW, &sched_idlespins, 0, 312737f4e025SAlexander Motin "Number of times idle thread will spin waiting for new work"); 312837f4e025SAlexander Motin SYSCTL_INT(_kern_sched, OID_AUTO, idlespinthresh, CTLFLAG_RW, 312937f4e025SAlexander Motin &sched_idlespinthresh, 0, 313037f4e025SAlexander Motin "Threshold before we will permit idle thread spinning"); 31317b8bfa0dSJeff Roberson #ifdef SMP 3132ae7a6b38SJeff Roberson SYSCTL_INT(_kern_sched, OID_AUTO, affinity, CTLFLAG_RW, &affinity, 0, 3133ae7a6b38SJeff Roberson "Number of hz ticks to keep thread affinity for"); 3134ae7a6b38SJeff Roberson SYSCTL_INT(_kern_sched, OID_AUTO, balance, CTLFLAG_RW, &rebalance, 0, 3135ae7a6b38SJeff Roberson "Enables the long-term load balancer"); 31367fcf154aSJeff Roberson SYSCTL_INT(_kern_sched, OID_AUTO, balance_interval, CTLFLAG_RW, 31377fcf154aSJeff Roberson &balance_interval, 0, 3138579895dfSAlexander Motin "Average period in stathz ticks to run the long-term balancer"); 3139ae7a6b38SJeff Roberson SYSCTL_INT(_kern_sched, OID_AUTO, steal_idle, CTLFLAG_RW, &steal_idle, 0, 3140ae7a6b38SJeff Roberson "Attempts to steal work from other cores before idling"); 314128994a58SJeff Roberson SYSCTL_INT(_kern_sched, OID_AUTO, steal_thresh, CTLFLAG_RW, &steal_thresh, 0, 314237f4e025SAlexander Motin "Minimum load on remote CPU before we'll steal"); 314397e9382dSDon Lewis SYSCTL_INT(_kern_sched, OID_AUTO, trysteal_limit, CTLFLAG_RW, &trysteal_limit, 314497e9382dSDon Lewis 0, "Topological distance limit for stealing threads in sched_switch()"); 314597e9382dSDon Lewis SYSCTL_INT(_kern_sched, OID_AUTO, always_steal, CTLFLAG_RW, &always_steal, 0, 314697e9382dSDon Lewis "Always run the stealer from the idle thread"); 314707095abfSIvan Voras SYSCTL_PROC(_kern_sched, OID_AUTO, topology_spec, CTLTYPE_STRING | 3148c69a1a50SMateusz Guzik CTLFLAG_MPSAFE | CTLFLAG_RD, NULL, 0, sysctl_kern_sched_topology_spec, "A", 314907095abfSIvan Voras "XML dump of detected CPU topology"); 31507b8bfa0dSJeff Roberson #endif 3151e7d50326SJeff Roberson 315254b0e65fSJeff Roberson /* ps compat. All cpu percentages from ULE are weighted. */ 3153a5423ea3SJeff Roberson static int ccpu = 0; 3154e7d50326SJeff Roberson SYSCTL_INT(_kern, OID_AUTO, ccpu, CTLFLAG_RD, &ccpu, 0, ""); 3155