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> 64af29f399SDmitry Chagin #include <sys/umtxvar.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)) 303*8bb173fbSAlexander Motin #define TDQ_TRYLOCK(t) mtx_trylock_spin(TDQ_LOCKPTR((t))) 304*8bb173fbSAlexander Motin #define TDQ_TRYLOCK_FLAGS(t, f) mtx_trylock_spin_flags(TDQ_LOCKPTR((t)), (f)) 305ae7a6b38SJeff Roberson #define TDQ_UNLOCK(t) mtx_unlock_spin(TDQ_LOCKPTR((t))) 3064ceaf45dSAttilio Rao #define TDQ_LOCKPTR(t) ((struct mtx *)(&(t)->tdq_lock)) 307ae7a6b38SJeff Roberson 3088460a577SJohn Birrell static void sched_priority(struct thread *); 30921381d1bSJeff Roberson static void sched_thread_priority(struct thread *, u_char); 3108460a577SJohn Birrell static int sched_interact_score(struct thread *); 3118460a577SJohn Birrell static void sched_interact_update(struct thread *); 3128460a577SJohn Birrell static void sched_interact_fork(struct thread *); 3137295465eSAlexander Motin static void sched_pctcpu_update(struct td_sched *, int); 31435e6168fSJeff Roberson 3155d7ef00cSJeff Roberson /* Operations on per processor queues */ 3169727e637SJeff Roberson static struct thread *tdq_choose(struct tdq *); 317018ff686SJeff Roberson static void tdq_setup(struct tdq *, int i); 3189727e637SJeff Roberson static void tdq_load_add(struct tdq *, struct thread *); 3199727e637SJeff Roberson static void tdq_load_rem(struct tdq *, struct thread *); 3209727e637SJeff Roberson static __inline void tdq_runq_add(struct tdq *, struct thread *, int); 3219727e637SJeff Roberson static __inline void tdq_runq_rem(struct tdq *, struct thread *); 322ff256d9cSJeff Roberson static inline int sched_shouldpreempt(int, int, int); 323ad1e7d28SJulian Elischer void tdq_print(int cpu); 324e7d50326SJeff Roberson static void runq_print(struct runq *rq); 325ae7a6b38SJeff Roberson static void tdq_add(struct tdq *, struct thread *, int); 3265d7ef00cSJeff Roberson #ifdef SMP 32797e9382dSDon Lewis static struct thread *tdq_move(struct tdq *, struct tdq *); 328ad1e7d28SJulian Elischer static int tdq_idled(struct tdq *); 32927ee18adSRyan Stone static void tdq_notify(struct tdq *, struct thread *); 3309727e637SJeff Roberson static struct thread *tdq_steal(struct tdq *, int); 3319727e637SJeff Roberson static struct thread *runq_steal(struct runq *, int); 3329727e637SJeff Roberson static int sched_pickcpu(struct thread *, int); 3337fcf154aSJeff Roberson static void sched_balance(void); 33462fa74d9SJeff Roberson static int sched_balance_pair(struct tdq *, struct tdq *); 3359727e637SJeff Roberson static inline struct tdq *sched_setcpu(struct thread *, int, int); 336ae7a6b38SJeff Roberson static inline void thread_unblock_switch(struct thread *, struct mtx *); 33707095abfSIvan Voras static int sysctl_kern_sched_topology_spec(SYSCTL_HANDLER_ARGS); 33807095abfSIvan Voras static int sysctl_kern_sched_topology_spec_internal(struct sbuf *sb, 33907095abfSIvan Voras struct cpu_group *cg, int indent); 3405d7ef00cSJeff Roberson #endif 3415d7ef00cSJeff Roberson 342e7d50326SJeff Roberson static void sched_setup(void *dummy); 343237fdd78SRobert Watson SYSINIT(sched_setup, SI_SUB_RUN_QUEUE, SI_ORDER_FIRST, sched_setup, NULL); 344e7d50326SJeff Roberson 345e7d50326SJeff Roberson static void sched_initticks(void *dummy); 346237fdd78SRobert Watson SYSINIT(sched_initticks, SI_SUB_CLOCKS, SI_ORDER_THIRD, sched_initticks, 347237fdd78SRobert Watson NULL); 348e7d50326SJeff Roberson 349b3e9e682SRyan Stone SDT_PROVIDER_DEFINE(sched); 350b3e9e682SRyan Stone 351d9fae5abSAndriy Gapon SDT_PROBE_DEFINE3(sched, , , change__pri, "struct thread *", 352b3e9e682SRyan Stone "struct proc *", "uint8_t"); 353d9fae5abSAndriy Gapon SDT_PROBE_DEFINE3(sched, , , dequeue, "struct thread *", 354b3e9e682SRyan Stone "struct proc *", "void *"); 355d9fae5abSAndriy Gapon SDT_PROBE_DEFINE4(sched, , , enqueue, "struct thread *", 356b3e9e682SRyan Stone "struct proc *", "void *", "int"); 357d9fae5abSAndriy Gapon SDT_PROBE_DEFINE4(sched, , , lend__pri, "struct thread *", 358b3e9e682SRyan Stone "struct proc *", "uint8_t", "struct thread *"); 359d9fae5abSAndriy Gapon SDT_PROBE_DEFINE2(sched, , , load__change, "int", "int"); 360d9fae5abSAndriy Gapon SDT_PROBE_DEFINE2(sched, , , off__cpu, "struct thread *", 361b3e9e682SRyan Stone "struct proc *"); 362d9fae5abSAndriy Gapon SDT_PROBE_DEFINE(sched, , , on__cpu); 363d9fae5abSAndriy Gapon SDT_PROBE_DEFINE(sched, , , remain__cpu); 364d9fae5abSAndriy Gapon SDT_PROBE_DEFINE2(sched, , , surrender, "struct thread *", 365b3e9e682SRyan Stone "struct proc *"); 366b3e9e682SRyan Stone 3670567b6ccSWarner Losh /* 368ae7a6b38SJeff Roberson * Print the threads waiting on a run-queue. 369ae7a6b38SJeff Roberson */ 370e7d50326SJeff Roberson static void 371e7d50326SJeff Roberson runq_print(struct runq *rq) 372e7d50326SJeff Roberson { 373e7d50326SJeff Roberson struct rqhead *rqh; 3749727e637SJeff Roberson struct thread *td; 375e7d50326SJeff Roberson int pri; 376e7d50326SJeff Roberson int j; 377e7d50326SJeff Roberson int i; 378e7d50326SJeff Roberson 379e7d50326SJeff Roberson for (i = 0; i < RQB_LEN; i++) { 380e7d50326SJeff Roberson printf("\t\trunq bits %d 0x%zx\n", 381e7d50326SJeff Roberson i, rq->rq_status.rqb_bits[i]); 382e7d50326SJeff Roberson for (j = 0; j < RQB_BPW; j++) 383e7d50326SJeff Roberson if (rq->rq_status.rqb_bits[i] & (1ul << j)) { 384e7d50326SJeff Roberson pri = j + (i << RQB_L2BPW); 385e7d50326SJeff Roberson rqh = &rq->rq_queues[pri]; 3869727e637SJeff Roberson TAILQ_FOREACH(td, rqh, td_runq) { 387e7d50326SJeff Roberson printf("\t\t\ttd %p(%s) priority %d rqindex %d pri %d\n", 3889727e637SJeff Roberson td, td->td_name, td->td_priority, 3899727e637SJeff Roberson td->td_rqindex, pri); 390e7d50326SJeff Roberson } 391e7d50326SJeff Roberson } 392e7d50326SJeff Roberson } 393e7d50326SJeff Roberson } 394e7d50326SJeff Roberson 395ae7a6b38SJeff Roberson /* 396ae7a6b38SJeff Roberson * Print the status of a per-cpu thread queue. Should be a ddb show cmd. 397ae7a6b38SJeff Roberson */ 39815dc847eSJeff Roberson void 399ad1e7d28SJulian Elischer tdq_print(int cpu) 40015dc847eSJeff Roberson { 401ad1e7d28SJulian Elischer struct tdq *tdq; 40215dc847eSJeff Roberson 403ad1e7d28SJulian Elischer tdq = TDQ_CPU(cpu); 40415dc847eSJeff Roberson 405c47f202bSJeff Roberson printf("tdq %d:\n", TDQ_ID(tdq)); 40662fa74d9SJeff Roberson printf("\tlock %p\n", TDQ_LOCKPTR(tdq)); 40762fa74d9SJeff Roberson printf("\tLock name: %s\n", tdq->tdq_name); 408d2ad694cSJeff Roberson printf("\tload: %d\n", tdq->tdq_load); 4091690c6c1SJeff Roberson printf("\tswitch cnt: %d\n", tdq->tdq_switchcnt); 4101690c6c1SJeff Roberson printf("\told switch cnt: %d\n", tdq->tdq_oldswitchcnt); 411e7d50326SJeff Roberson printf("\ttimeshare idx: %d\n", tdq->tdq_idx); 4123f872f85SJeff Roberson printf("\ttimeshare ridx: %d\n", tdq->tdq_ridx); 4131690c6c1SJeff Roberson printf("\tload transferable: %d\n", tdq->tdq_transferable); 4141690c6c1SJeff Roberson printf("\tlowest priority: %d\n", tdq->tdq_lowpri); 415e7d50326SJeff Roberson printf("\trealtime runq:\n"); 416e7d50326SJeff Roberson runq_print(&tdq->tdq_realtime); 417e7d50326SJeff Roberson printf("\ttimeshare runq:\n"); 418e7d50326SJeff Roberson runq_print(&tdq->tdq_timeshare); 419e7d50326SJeff Roberson printf("\tidle runq:\n"); 420e7d50326SJeff Roberson runq_print(&tdq->tdq_idle); 42115dc847eSJeff Roberson } 42215dc847eSJeff Roberson 423ff256d9cSJeff Roberson static inline int 424ff256d9cSJeff Roberson sched_shouldpreempt(int pri, int cpri, int remote) 425ff256d9cSJeff Roberson { 426ff256d9cSJeff Roberson /* 427ff256d9cSJeff Roberson * If the new priority is not better than the current priority there is 428ff256d9cSJeff Roberson * nothing to do. 429ff256d9cSJeff Roberson */ 430ff256d9cSJeff Roberson if (pri >= cpri) 431ff256d9cSJeff Roberson return (0); 432ff256d9cSJeff Roberson /* 433ff256d9cSJeff Roberson * Always preempt idle. 434ff256d9cSJeff Roberson */ 435ff256d9cSJeff Roberson if (cpri >= PRI_MIN_IDLE) 436ff256d9cSJeff Roberson return (1); 437ff256d9cSJeff Roberson /* 438ff256d9cSJeff Roberson * If preemption is disabled don't preempt others. 439ff256d9cSJeff Roberson */ 440ff256d9cSJeff Roberson if (preempt_thresh == 0) 441ff256d9cSJeff Roberson return (0); 442ff256d9cSJeff Roberson /* 443ff256d9cSJeff Roberson * Preempt if we exceed the threshold. 444ff256d9cSJeff Roberson */ 445ff256d9cSJeff Roberson if (pri <= preempt_thresh) 446ff256d9cSJeff Roberson return (1); 447ff256d9cSJeff Roberson /* 44812d56c0fSJohn Baldwin * If we're interactive or better and there is non-interactive 44912d56c0fSJohn Baldwin * or worse running preempt only remote processors. 450ff256d9cSJeff Roberson */ 45112d56c0fSJohn Baldwin if (remote && pri <= PRI_MAX_INTERACT && cpri > PRI_MAX_INTERACT) 452ff256d9cSJeff Roberson return (1); 453ff256d9cSJeff Roberson return (0); 454ff256d9cSJeff Roberson } 455ff256d9cSJeff Roberson 456ae7a6b38SJeff Roberson /* 457ae7a6b38SJeff Roberson * Add a thread to the actual run-queue. Keeps transferable counts up to 458ae7a6b38SJeff Roberson * date with what is actually on the run-queue. Selects the correct 459ae7a6b38SJeff Roberson * queue position for timeshare threads. 460ae7a6b38SJeff Roberson */ 461155b9987SJeff Roberson static __inline void 4629727e637SJeff Roberson tdq_runq_add(struct tdq *tdq, struct thread *td, int flags) 463155b9987SJeff Roberson { 4649727e637SJeff Roberson struct td_sched *ts; 465c143ac21SJeff Roberson u_char pri; 466c143ac21SJeff Roberson 467ae7a6b38SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED); 46861a74c5cSJeff Roberson THREAD_LOCK_BLOCKED_ASSERT(td, MA_OWNED); 46973daf66fSJeff Roberson 4709727e637SJeff Roberson pri = td->td_priority; 47193ccd6bfSKonstantin Belousov ts = td_get_sched(td); 4729727e637SJeff Roberson TD_SET_RUNQ(td); 4739727e637SJeff Roberson if (THREAD_CAN_MIGRATE(td)) { 474d2ad694cSJeff Roberson tdq->tdq_transferable++; 475ad1e7d28SJulian Elischer ts->ts_flags |= TSF_XFERABLE; 47680f86c9fSJeff Roberson } 47712d56c0fSJohn Baldwin if (pri < PRI_MIN_BATCH) { 478c143ac21SJeff Roberson ts->ts_runq = &tdq->tdq_realtime; 47912d56c0fSJohn Baldwin } else if (pri <= PRI_MAX_BATCH) { 480c143ac21SJeff Roberson ts->ts_runq = &tdq->tdq_timeshare; 48112d56c0fSJohn Baldwin KASSERT(pri <= PRI_MAX_BATCH && pri >= PRI_MIN_BATCH, 482e7d50326SJeff Roberson ("Invalid priority %d on timeshare runq", pri)); 483e7d50326SJeff Roberson /* 484e7d50326SJeff Roberson * This queue contains only priorities between MIN and MAX 485e7d50326SJeff Roberson * realtime. Use the whole queue to represent these values. 486e7d50326SJeff Roberson */ 487c47f202bSJeff Roberson if ((flags & (SRQ_BORROWING|SRQ_PREEMPTED)) == 0) { 48816705791SAndriy Gapon pri = RQ_NQS * (pri - PRI_MIN_BATCH) / PRI_BATCH_RANGE; 489e7d50326SJeff Roberson pri = (pri + tdq->tdq_idx) % RQ_NQS; 4903f872f85SJeff Roberson /* 4913f872f85SJeff Roberson * This effectively shortens the queue by one so we 4923f872f85SJeff Roberson * can have a one slot difference between idx and 4933f872f85SJeff Roberson * ridx while we wait for threads to drain. 4943f872f85SJeff Roberson */ 4953f872f85SJeff Roberson if (tdq->tdq_ridx != tdq->tdq_idx && 4963f872f85SJeff Roberson pri == tdq->tdq_ridx) 4974499aff6SJeff Roberson pri = (unsigned char)(pri - 1) % RQ_NQS; 498e7d50326SJeff Roberson } else 4993f872f85SJeff Roberson pri = tdq->tdq_ridx; 5009727e637SJeff Roberson runq_add_pri(ts->ts_runq, td, pri, flags); 501c143ac21SJeff Roberson return; 502e7d50326SJeff Roberson } else 50373daf66fSJeff Roberson ts->ts_runq = &tdq->tdq_idle; 5049727e637SJeff Roberson runq_add(ts->ts_runq, td, flags); 50573daf66fSJeff Roberson } 50673daf66fSJeff Roberson 50773daf66fSJeff Roberson /* 508ae7a6b38SJeff Roberson * Remove a thread from a run-queue. This typically happens when a thread 509ae7a6b38SJeff Roberson * is selected to run. Running threads are not on the queue and the 510ae7a6b38SJeff Roberson * transferable count does not reflect them. 511ae7a6b38SJeff Roberson */ 512155b9987SJeff Roberson static __inline void 5139727e637SJeff Roberson tdq_runq_rem(struct tdq *tdq, struct thread *td) 514155b9987SJeff Roberson { 5159727e637SJeff Roberson struct td_sched *ts; 5169727e637SJeff Roberson 51793ccd6bfSKonstantin Belousov ts = td_get_sched(td); 518ae7a6b38SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED); 51961a74c5cSJeff Roberson THREAD_LOCK_BLOCKED_ASSERT(td, MA_OWNED); 520ae7a6b38SJeff Roberson KASSERT(ts->ts_runq != NULL, 5219727e637SJeff Roberson ("tdq_runq_remove: thread %p null ts_runq", td)); 522ad1e7d28SJulian Elischer if (ts->ts_flags & TSF_XFERABLE) { 523d2ad694cSJeff Roberson tdq->tdq_transferable--; 524ad1e7d28SJulian Elischer ts->ts_flags &= ~TSF_XFERABLE; 52580f86c9fSJeff Roberson } 5263f872f85SJeff Roberson if (ts->ts_runq == &tdq->tdq_timeshare) { 5273f872f85SJeff Roberson if (tdq->tdq_idx != tdq->tdq_ridx) 5289727e637SJeff Roberson runq_remove_idx(ts->ts_runq, td, &tdq->tdq_ridx); 529e7d50326SJeff Roberson else 5309727e637SJeff Roberson runq_remove_idx(ts->ts_runq, td, NULL); 5313f872f85SJeff Roberson } else 5329727e637SJeff Roberson runq_remove(ts->ts_runq, td); 533155b9987SJeff Roberson } 534155b9987SJeff Roberson 535ae7a6b38SJeff Roberson /* 536ae7a6b38SJeff Roberson * Load is maintained for all threads RUNNING and ON_RUNQ. Add the load 537ae7a6b38SJeff Roberson * for this thread to the referenced thread queue. 538ae7a6b38SJeff Roberson */ 539a8949de2SJeff Roberson static void 5409727e637SJeff Roberson tdq_load_add(struct tdq *tdq, struct thread *td) 5415d7ef00cSJeff Roberson { 542ae7a6b38SJeff Roberson 543ae7a6b38SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED); 54461a74c5cSJeff Roberson THREAD_LOCK_BLOCKED_ASSERT(td, MA_OWNED); 54503d17db7SJeff Roberson 546d2ad694cSJeff Roberson tdq->tdq_load++; 5471b9d701fSAttilio Rao if ((td->td_flags & TDF_NOLOAD) == 0) 548d2ad694cSJeff Roberson tdq->tdq_sysload++; 5498f51ad55SJeff Roberson KTR_COUNTER0(KTR_SCHED, "load", tdq->tdq_loadname, tdq->tdq_load); 550d9fae5abSAndriy Gapon SDT_PROBE2(sched, , , load__change, (int)TDQ_ID(tdq), tdq->tdq_load); 5515d7ef00cSJeff Roberson } 55215dc847eSJeff Roberson 553ae7a6b38SJeff Roberson /* 554ae7a6b38SJeff Roberson * Remove the load from a thread that is transitioning to a sleep state or 555ae7a6b38SJeff Roberson * exiting. 556ae7a6b38SJeff Roberson */ 557a8949de2SJeff Roberson static void 5589727e637SJeff Roberson tdq_load_rem(struct tdq *tdq, struct thread *td) 5595d7ef00cSJeff Roberson { 560ae7a6b38SJeff Roberson 561ae7a6b38SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED); 56261a74c5cSJeff Roberson THREAD_LOCK_BLOCKED_ASSERT(td, MA_OWNED); 563ae7a6b38SJeff Roberson KASSERT(tdq->tdq_load != 0, 564c47f202bSJeff Roberson ("tdq_load_rem: Removing with 0 load on queue %d", TDQ_ID(tdq))); 56503d17db7SJeff Roberson 566d2ad694cSJeff Roberson tdq->tdq_load--; 5671b9d701fSAttilio Rao if ((td->td_flags & TDF_NOLOAD) == 0) 56803d17db7SJeff Roberson tdq->tdq_sysload--; 5698f51ad55SJeff Roberson KTR_COUNTER0(KTR_SCHED, "load", tdq->tdq_loadname, tdq->tdq_load); 570d9fae5abSAndriy Gapon SDT_PROBE2(sched, , , load__change, (int)TDQ_ID(tdq), tdq->tdq_load); 57115dc847eSJeff Roberson } 57215dc847eSJeff Roberson 573356500a3SJeff Roberson /* 5745e5c3873SJeff Roberson * Bound timeshare latency by decreasing slice size as load increases. We 5755e5c3873SJeff Roberson * consider the maximum latency as the sum of the threads waiting to run 5765e5c3873SJeff Roberson * aside from curthread and target no more than sched_slice latency but 5775e5c3873SJeff Roberson * no less than sched_slice_min runtime. 5785e5c3873SJeff Roberson */ 5795e5c3873SJeff Roberson static inline int 5805e5c3873SJeff Roberson tdq_slice(struct tdq *tdq) 5815e5c3873SJeff Roberson { 5825e5c3873SJeff Roberson int load; 5835e5c3873SJeff Roberson 5845e5c3873SJeff Roberson /* 5855e5c3873SJeff Roberson * It is safe to use sys_load here because this is called from 5865e5c3873SJeff Roberson * contexts where timeshare threads are running and so there 5875e5c3873SJeff Roberson * cannot be higher priority load in the system. 5885e5c3873SJeff Roberson */ 5895e5c3873SJeff Roberson load = tdq->tdq_sysload - 1; 5905e5c3873SJeff Roberson if (load >= SCHED_SLICE_MIN_DIVISOR) 5915e5c3873SJeff Roberson return (sched_slice_min); 5925e5c3873SJeff Roberson if (load <= 1) 5935e5c3873SJeff Roberson return (sched_slice); 5945e5c3873SJeff Roberson return (sched_slice / load); 5955e5c3873SJeff Roberson } 5965e5c3873SJeff Roberson 5975e5c3873SJeff Roberson /* 59862fa74d9SJeff Roberson * Set lowpri to its exact value by searching the run-queue and 59962fa74d9SJeff Roberson * evaluating curthread. curthread may be passed as an optimization. 600356500a3SJeff Roberson */ 60122bf7d9aSJeff Roberson static void 60262fa74d9SJeff Roberson tdq_setlowpri(struct tdq *tdq, struct thread *ctd) 60362fa74d9SJeff Roberson { 60462fa74d9SJeff Roberson struct thread *td; 60562fa74d9SJeff Roberson 60662fa74d9SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED); 60762fa74d9SJeff Roberson if (ctd == NULL) 60862fa74d9SJeff Roberson ctd = pcpu_find(TDQ_ID(tdq))->pc_curthread; 6099727e637SJeff Roberson td = tdq_choose(tdq); 6109727e637SJeff Roberson if (td == NULL || td->td_priority > ctd->td_priority) 61162fa74d9SJeff Roberson tdq->tdq_lowpri = ctd->td_priority; 61262fa74d9SJeff Roberson else 61362fa74d9SJeff Roberson tdq->tdq_lowpri = td->td_priority; 61462fa74d9SJeff Roberson } 61562fa74d9SJeff Roberson 61662fa74d9SJeff Roberson #ifdef SMP 6179129dd59SPedro F. Giffuni /* 6189129dd59SPedro F. Giffuni * We need some randomness. Implement a classic Linear Congruential 6199129dd59SPedro F. Giffuni * Generator X_{n+1}=(aX_n+c) mod m. These values are optimized for 6209129dd59SPedro F. Giffuni * m = 2^32, a = 69069 and c = 5. We only return the upper 16 bits 6219129dd59SPedro F. Giffuni * of the random state (in the low bits of our answer) to keep 6229129dd59SPedro F. Giffuni * the maximum randomness. 6239129dd59SPedro F. Giffuni */ 6249129dd59SPedro F. Giffuni static uint32_t 6259129dd59SPedro F. Giffuni sched_random(void) 6269129dd59SPedro F. Giffuni { 6279129dd59SPedro F. Giffuni uint32_t *rndptr; 6289129dd59SPedro F. Giffuni 6299129dd59SPedro F. Giffuni rndptr = DPCPU_PTR(randomval); 6309129dd59SPedro F. Giffuni *rndptr = *rndptr * 69069 + 5; 6319129dd59SPedro F. Giffuni 6329129dd59SPedro F. Giffuni return (*rndptr >> 16); 6339129dd59SPedro F. Giffuni } 6349129dd59SPedro F. Giffuni 63562fa74d9SJeff Roberson struct cpu_search { 636aefe0a8cSAlexander Motin cpuset_t *cs_mask; 63736acfc65SAlexander Motin u_int cs_prefer; 63836acfc65SAlexander Motin int cs_pri; /* Min priority for low. */ 63936acfc65SAlexander Motin int cs_limit; /* Max load for low, min load for high. */ 640aefe0a8cSAlexander Motin }; 641aefe0a8cSAlexander Motin 642aefe0a8cSAlexander Motin struct cpu_search_res { 64336acfc65SAlexander Motin int cs_cpu; 64436acfc65SAlexander Motin int cs_load; 64562fa74d9SJeff Roberson }; 64662fa74d9SJeff Roberson 64762fa74d9SJeff Roberson /* 648aefe0a8cSAlexander Motin * Search the tree of cpu_groups for the lowest or highest loaded CPU. 649aefe0a8cSAlexander Motin * These routines actually compare the load on all paths through the tree 650aefe0a8cSAlexander Motin * and find the least loaded cpu on the least loaded path, which may differ 651aefe0a8cSAlexander Motin * from the least loaded cpu in the system. This balances work among caches 652aefe0a8cSAlexander Motin * and buses. 65362fa74d9SJeff Roberson */ 654aefe0a8cSAlexander Motin static int 655aefe0a8cSAlexander Motin cpu_search_lowest(const struct cpu_group *cg, const struct cpu_search *s, 656aefe0a8cSAlexander Motin struct cpu_search_res *r) 65762fa74d9SJeff Roberson { 658aefe0a8cSAlexander Motin struct cpu_search_res lr; 65936acfc65SAlexander Motin struct tdq *tdq; 660aefe0a8cSAlexander Motin int c, bload, l, load, total; 66162fa74d9SJeff Roberson 66236acfc65SAlexander Motin total = 0; 663aefe0a8cSAlexander Motin bload = INT_MAX; 664aefe0a8cSAlexander Motin r->cs_cpu = -1; 66536acfc65SAlexander Motin 666aefe0a8cSAlexander Motin /* Loop through children CPU groups if there are any. */ 667aefe0a8cSAlexander Motin if (cg->cg_children > 0) { 668aefe0a8cSAlexander Motin for (c = cg->cg_children - 1; c >= 0; c--) { 669aefe0a8cSAlexander Motin load = cpu_search_lowest(&cg->cg_child[c], s, &lr); 67036acfc65SAlexander Motin total += load; 671aefe0a8cSAlexander Motin if (lr.cs_cpu >= 0 && (load < bload || 672aefe0a8cSAlexander Motin (load == bload && lr.cs_load < r->cs_load))) { 673aefe0a8cSAlexander Motin bload = load; 674aefe0a8cSAlexander Motin r->cs_cpu = lr.cs_cpu; 675aefe0a8cSAlexander Motin r->cs_load = lr.cs_load; 67636acfc65SAlexander Motin } 67736acfc65SAlexander Motin } 67862fa74d9SJeff Roberson return (total); 67962fa74d9SJeff Roberson } 68062fa74d9SJeff Roberson 681aefe0a8cSAlexander Motin /* Loop through children CPUs otherwise. */ 682aefe0a8cSAlexander Motin for (c = cg->cg_last; c >= cg->cg_first; c--) { 683aefe0a8cSAlexander Motin if (!CPU_ISSET(c, &cg->cg_mask)) 684aefe0a8cSAlexander Motin continue; 685aefe0a8cSAlexander Motin tdq = TDQ_CPU(c); 686aefe0a8cSAlexander Motin l = tdq->tdq_load; 687aefe0a8cSAlexander Motin load = l * 256; 688aefe0a8cSAlexander Motin if (c == s->cs_prefer) 689aefe0a8cSAlexander Motin load -= 128; 690aefe0a8cSAlexander Motin total += load; 691aefe0a8cSAlexander Motin if (l > s->cs_limit || tdq->tdq_lowpri <= s->cs_pri || 692aefe0a8cSAlexander Motin !CPU_ISSET(c, s->cs_mask)) 693aefe0a8cSAlexander Motin continue; 694aefe0a8cSAlexander Motin load -= sched_random() % 128; 695aefe0a8cSAlexander Motin if (load < bload) { 696aefe0a8cSAlexander Motin bload = load; 697aefe0a8cSAlexander Motin r->cs_cpu = c; 698aefe0a8cSAlexander Motin } 699aefe0a8cSAlexander Motin } 700aefe0a8cSAlexander Motin r->cs_load = bload; 701aefe0a8cSAlexander Motin return (total); 70262fa74d9SJeff Roberson } 70362fa74d9SJeff Roberson 704aefe0a8cSAlexander Motin static int 705aefe0a8cSAlexander Motin cpu_search_highest(const struct cpu_group *cg, const struct cpu_search *s, 706aefe0a8cSAlexander Motin struct cpu_search_res *r) 70762fa74d9SJeff Roberson { 708aefe0a8cSAlexander Motin struct cpu_search_res lr; 709aefe0a8cSAlexander Motin struct tdq *tdq; 710aefe0a8cSAlexander Motin int c, bload, l, load, total; 711aefe0a8cSAlexander Motin 712aefe0a8cSAlexander Motin total = 0; 713aefe0a8cSAlexander Motin bload = INT_MIN; 714aefe0a8cSAlexander Motin r->cs_cpu = -1; 715aefe0a8cSAlexander Motin 716aefe0a8cSAlexander Motin /* Loop through children CPU groups if there are any. */ 717aefe0a8cSAlexander Motin if (cg->cg_children > 0) { 718aefe0a8cSAlexander Motin for (c = cg->cg_children - 1; c >= 0; c--) { 719aefe0a8cSAlexander Motin load = cpu_search_highest(&cg->cg_child[c], s, &lr); 720aefe0a8cSAlexander Motin total += load; 721aefe0a8cSAlexander Motin if (lr.cs_cpu >= 0 && (load > bload || 722aefe0a8cSAlexander Motin (load == bload && lr.cs_load > r->cs_load))) { 723aefe0a8cSAlexander Motin bload = load; 724aefe0a8cSAlexander Motin r->cs_cpu = lr.cs_cpu; 725aefe0a8cSAlexander Motin r->cs_load = lr.cs_load; 726aefe0a8cSAlexander Motin } 727aefe0a8cSAlexander Motin } 728aefe0a8cSAlexander Motin return (total); 72962fa74d9SJeff Roberson } 73062fa74d9SJeff Roberson 731aefe0a8cSAlexander Motin /* Loop through children CPUs otherwise. */ 732aefe0a8cSAlexander Motin for (c = cg->cg_last; c >= cg->cg_first; c--) { 733aefe0a8cSAlexander Motin if (!CPU_ISSET(c, &cg->cg_mask)) 734aefe0a8cSAlexander Motin continue; 735aefe0a8cSAlexander Motin tdq = TDQ_CPU(c); 736aefe0a8cSAlexander Motin l = tdq->tdq_load; 737aefe0a8cSAlexander Motin load = l * 256; 738aefe0a8cSAlexander Motin total += load; 739aefe0a8cSAlexander Motin if (l < s->cs_limit || !tdq->tdq_transferable || 740aefe0a8cSAlexander Motin !CPU_ISSET(c, s->cs_mask)) 741aefe0a8cSAlexander Motin continue; 742aefe0a8cSAlexander Motin load -= sched_random() % 128; 743aefe0a8cSAlexander Motin if (load > bload) { 744aefe0a8cSAlexander Motin bload = load; 745aefe0a8cSAlexander Motin r->cs_cpu = c; 746aefe0a8cSAlexander Motin } 747aefe0a8cSAlexander Motin } 748aefe0a8cSAlexander Motin r->cs_load = bload; 749aefe0a8cSAlexander Motin return (total); 75062fa74d9SJeff Roberson } 75162fa74d9SJeff Roberson 75262fa74d9SJeff Roberson /* 75362fa74d9SJeff Roberson * Find the cpu with the least load via the least loaded path that has a 75462fa74d9SJeff Roberson * lowpri greater than pri pri. A pri of -1 indicates any priority is 75562fa74d9SJeff Roberson * acceptable. 75662fa74d9SJeff Roberson */ 75762fa74d9SJeff Roberson static inline int 758aefe0a8cSAlexander Motin sched_lowest(const struct cpu_group *cg, cpuset_t *mask, int pri, int maxload, 75936acfc65SAlexander Motin int prefer) 76062fa74d9SJeff Roberson { 761aefe0a8cSAlexander Motin struct cpu_search s; 762aefe0a8cSAlexander Motin struct cpu_search_res r; 76362fa74d9SJeff Roberson 764aefe0a8cSAlexander Motin s.cs_prefer = prefer; 765aefe0a8cSAlexander Motin s.cs_mask = mask; 766aefe0a8cSAlexander Motin s.cs_pri = pri; 767aefe0a8cSAlexander Motin s.cs_limit = maxload; 768aefe0a8cSAlexander Motin cpu_search_lowest(cg, &s, &r); 769aefe0a8cSAlexander Motin return (r.cs_cpu); 77062fa74d9SJeff Roberson } 77162fa74d9SJeff Roberson 77262fa74d9SJeff Roberson /* 77362fa74d9SJeff Roberson * Find the cpu with the highest load via the highest loaded path. 77462fa74d9SJeff Roberson */ 77562fa74d9SJeff Roberson static inline int 776aefe0a8cSAlexander Motin sched_highest(const struct cpu_group *cg, cpuset_t *mask, int minload) 77762fa74d9SJeff Roberson { 778aefe0a8cSAlexander Motin struct cpu_search s; 779aefe0a8cSAlexander Motin struct cpu_search_res r; 78062fa74d9SJeff Roberson 781aefe0a8cSAlexander Motin s.cs_mask = mask; 782aefe0a8cSAlexander Motin s.cs_limit = minload; 783aefe0a8cSAlexander Motin cpu_search_highest(cg, &s, &r); 784aefe0a8cSAlexander Motin return (r.cs_cpu); 78562fa74d9SJeff Roberson } 78662fa74d9SJeff Roberson 78762fa74d9SJeff Roberson static void 78862fa74d9SJeff Roberson sched_balance_group(struct cpu_group *cg) 78962fa74d9SJeff Roberson { 790018ff686SJeff Roberson struct tdq *tdq; 79136acfc65SAlexander Motin cpuset_t hmask, lmask; 79236acfc65SAlexander Motin int high, low, anylow; 79362fa74d9SJeff Roberson 79436acfc65SAlexander Motin CPU_FILL(&hmask); 79562fa74d9SJeff Roberson for (;;) { 796aefe0a8cSAlexander Motin high = sched_highest(cg, &hmask, 2); 79736acfc65SAlexander Motin /* Stop if there is no more CPU with transferrable threads. */ 79836acfc65SAlexander Motin if (high == -1) 79962fa74d9SJeff Roberson break; 80036acfc65SAlexander Motin CPU_CLR(high, &hmask); 80136acfc65SAlexander Motin CPU_COPY(&hmask, &lmask); 80236acfc65SAlexander Motin /* Stop if there is no more CPU left for low. */ 80336acfc65SAlexander Motin if (CPU_EMPTY(&lmask)) 80462fa74d9SJeff Roberson break; 80536acfc65SAlexander Motin anylow = 1; 806018ff686SJeff Roberson tdq = TDQ_CPU(high); 80736acfc65SAlexander Motin nextlow: 808aefe0a8cSAlexander Motin low = sched_lowest(cg, &lmask, -1, tdq->tdq_load - 1, high); 80936acfc65SAlexander Motin /* Stop if we looked well and found no less loaded CPU. */ 81036acfc65SAlexander Motin if (anylow && low == -1) 81136acfc65SAlexander Motin break; 81236acfc65SAlexander Motin /* Go to next high if we found no less loaded CPU. */ 81336acfc65SAlexander Motin if (low == -1) 81436acfc65SAlexander Motin continue; 81536acfc65SAlexander Motin /* Transfer thread from high to low. */ 816018ff686SJeff Roberson if (sched_balance_pair(tdq, TDQ_CPU(low))) { 81736acfc65SAlexander Motin /* CPU that got thread can no longer be a donor. */ 81836acfc65SAlexander Motin CPU_CLR(low, &hmask); 81936acfc65SAlexander Motin } else { 82062fa74d9SJeff Roberson /* 82136acfc65SAlexander Motin * If failed, then there is no threads on high 82236acfc65SAlexander Motin * that can run on this low. Drop low from low 82336acfc65SAlexander Motin * mask and look for different one. 82462fa74d9SJeff Roberson */ 82536acfc65SAlexander Motin CPU_CLR(low, &lmask); 82636acfc65SAlexander Motin anylow = 0; 82736acfc65SAlexander Motin goto nextlow; 82862fa74d9SJeff Roberson } 82936acfc65SAlexander Motin } 83062fa74d9SJeff Roberson } 83162fa74d9SJeff Roberson 83262fa74d9SJeff Roberson static void 83362375ca8SEd Schouten sched_balance(void) 834356500a3SJeff Roberson { 8357fcf154aSJeff Roberson struct tdq *tdq; 836356500a3SJeff Roberson 8370567b6ccSWarner Losh balance_ticks = max(balance_interval / 2, 1) + 838b250ad34SWarner Losh (sched_random() % balance_interval); 8397fcf154aSJeff Roberson tdq = TDQ_SELF(); 8407fcf154aSJeff Roberson TDQ_UNLOCK(tdq); 84162fa74d9SJeff Roberson sched_balance_group(cpu_top); 8427fcf154aSJeff Roberson TDQ_LOCK(tdq); 843cac77d04SJeff Roberson } 84486f8ae96SJeff Roberson 845ae7a6b38SJeff Roberson /* 846ae7a6b38SJeff Roberson * Lock two thread queues using their address to maintain lock order. 847ae7a6b38SJeff Roberson */ 848ae7a6b38SJeff Roberson static void 849ae7a6b38SJeff Roberson tdq_lock_pair(struct tdq *one, struct tdq *two) 850ae7a6b38SJeff Roberson { 851ae7a6b38SJeff Roberson if (one < two) { 852ae7a6b38SJeff Roberson TDQ_LOCK(one); 853ae7a6b38SJeff Roberson TDQ_LOCK_FLAGS(two, MTX_DUPOK); 854ae7a6b38SJeff Roberson } else { 855ae7a6b38SJeff Roberson TDQ_LOCK(two); 856ae7a6b38SJeff Roberson TDQ_LOCK_FLAGS(one, MTX_DUPOK); 857ae7a6b38SJeff Roberson } 858ae7a6b38SJeff Roberson } 859ae7a6b38SJeff Roberson 860ae7a6b38SJeff Roberson /* 8617fcf154aSJeff Roberson * Unlock two thread queues. Order is not important here. 8627fcf154aSJeff Roberson */ 8637fcf154aSJeff Roberson static void 8647fcf154aSJeff Roberson tdq_unlock_pair(struct tdq *one, struct tdq *two) 8657fcf154aSJeff Roberson { 8667fcf154aSJeff Roberson TDQ_UNLOCK(one); 8677fcf154aSJeff Roberson TDQ_UNLOCK(two); 8687fcf154aSJeff Roberson } 8697fcf154aSJeff Roberson 8707fcf154aSJeff Roberson /* 871ae7a6b38SJeff Roberson * Transfer load between two imbalanced thread queues. 872ae7a6b38SJeff Roberson */ 87362fa74d9SJeff Roberson static int 874ad1e7d28SJulian Elischer sched_balance_pair(struct tdq *high, struct tdq *low) 875cac77d04SJeff Roberson { 87697e9382dSDon Lewis struct thread *td; 877880bf8b9SMarius Strobl int cpu; 878cac77d04SJeff Roberson 879ae7a6b38SJeff Roberson tdq_lock_pair(high, low); 88097e9382dSDon Lewis td = NULL; 881155b9987SJeff Roberson /* 88297e9382dSDon Lewis * Transfer a thread from high to low. 883155b9987SJeff Roberson */ 88436acfc65SAlexander Motin if (high->tdq_transferable != 0 && high->tdq_load > low->tdq_load && 88597e9382dSDon Lewis (td = tdq_move(high, low)) != NULL) { 886a5423ea3SJeff Roberson /* 88797e9382dSDon Lewis * In case the target isn't the current cpu notify it of the 88897e9382dSDon Lewis * new load, possibly sending an IPI to force it to reschedule. 889a5423ea3SJeff Roberson */ 890880bf8b9SMarius Strobl cpu = TDQ_ID(low); 891880bf8b9SMarius Strobl if (cpu != PCPU_GET(cpuid)) 89297e9382dSDon Lewis tdq_notify(low, td); 893ae7a6b38SJeff Roberson } 8947fcf154aSJeff Roberson tdq_unlock_pair(high, low); 89597e9382dSDon Lewis return (td != NULL); 896356500a3SJeff Roberson } 897356500a3SJeff Roberson 898ae7a6b38SJeff Roberson /* 899ae7a6b38SJeff Roberson * Move a thread from one thread queue to another. 900ae7a6b38SJeff Roberson */ 90197e9382dSDon Lewis static struct thread * 902ae7a6b38SJeff Roberson tdq_move(struct tdq *from, struct tdq *to) 903356500a3SJeff Roberson { 904ae7a6b38SJeff Roberson struct thread *td; 905ae7a6b38SJeff Roberson struct tdq *tdq; 906ae7a6b38SJeff Roberson int cpu; 907356500a3SJeff Roberson 9087fcf154aSJeff Roberson TDQ_LOCK_ASSERT(from, MA_OWNED); 9097fcf154aSJeff Roberson TDQ_LOCK_ASSERT(to, MA_OWNED); 9107fcf154aSJeff Roberson 911ad1e7d28SJulian Elischer tdq = from; 912ae7a6b38SJeff Roberson cpu = TDQ_ID(to); 9139727e637SJeff Roberson td = tdq_steal(tdq, cpu); 9149727e637SJeff Roberson if (td == NULL) 91597e9382dSDon Lewis return (NULL); 91661a74c5cSJeff Roberson 917ae7a6b38SJeff Roberson /* 91861a74c5cSJeff Roberson * Although the run queue is locked the thread may be 91961a74c5cSJeff Roberson * blocked. We can not set the lock until it is unblocked. 920ae7a6b38SJeff Roberson */ 92161a74c5cSJeff Roberson thread_lock_block_wait(td); 922ae7a6b38SJeff Roberson sched_rem(td); 92361a74c5cSJeff Roberson THREAD_LOCKPTR_ASSERT(td, TDQ_LOCKPTR(from)); 924ae7a6b38SJeff Roberson td->td_lock = TDQ_LOCKPTR(to); 92561a74c5cSJeff Roberson td_get_sched(td)->ts_cpu = cpu; 926ae7a6b38SJeff Roberson tdq_add(to, td, SRQ_YIELDING); 92761a74c5cSJeff Roberson 92897e9382dSDon Lewis return (td); 929356500a3SJeff Roberson } 93022bf7d9aSJeff Roberson 931ae7a6b38SJeff Roberson /* 932ae7a6b38SJeff Roberson * This tdq has idled. Try to steal a thread from another cpu and switch 933ae7a6b38SJeff Roberson * to it. 934ae7a6b38SJeff Roberson */ 93580f86c9fSJeff Roberson static int 936ad1e7d28SJulian Elischer tdq_idled(struct tdq *tdq) 93722bf7d9aSJeff Roberson { 9382668bb2aSAlexander Motin struct cpu_group *cg, *parent; 939ad1e7d28SJulian Elischer struct tdq *steal; 940c76ee827SJeff Roberson cpuset_t mask; 9412668bb2aSAlexander Motin int cpu, switchcnt, goup; 94280f86c9fSJeff Roberson 94397e9382dSDon Lewis if (smp_started == 0 || steal_idle == 0 || tdq->tdq_cg == NULL) 94488f530ccSJeff Roberson return (1); 945c76ee827SJeff Roberson CPU_FILL(&mask); 946c76ee827SJeff Roberson CPU_CLR(PCPU_GET(cpuid), &mask); 94797e9382dSDon Lewis restart: 94897e9382dSDon Lewis switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt; 9492668bb2aSAlexander Motin for (cg = tdq->tdq_cg, goup = 0; ; ) { 950aefe0a8cSAlexander Motin cpu = sched_highest(cg, &mask, steal_thresh); 95197e9382dSDon Lewis /* 95297e9382dSDon Lewis * We were assigned a thread but not preempted. Returning 95397e9382dSDon Lewis * 0 here will cause our caller to switch to it. 95497e9382dSDon Lewis */ 95597e9382dSDon Lewis if (tdq->tdq_load) 95697e9382dSDon Lewis return (0); 9572668bb2aSAlexander Motin 9582668bb2aSAlexander Motin /* 9592668bb2aSAlexander Motin * We found no CPU to steal from in this group. Escalate to 9602668bb2aSAlexander Motin * the parent and repeat. But if parent has only two children 9612668bb2aSAlexander Motin * groups we can avoid searching this group again by searching 9622668bb2aSAlexander Motin * the other one specifically and then escalating two levels. 9632668bb2aSAlexander Motin */ 96462fa74d9SJeff Roberson if (cpu == -1) { 9652668bb2aSAlexander Motin if (goup) { 96662fa74d9SJeff Roberson cg = cg->cg_parent; 9672668bb2aSAlexander Motin goup = 0; 9682668bb2aSAlexander Motin } 9692668bb2aSAlexander Motin parent = cg->cg_parent; 9702668bb2aSAlexander Motin if (parent == NULL) 97197e9382dSDon Lewis return (1); 9722668bb2aSAlexander Motin if (parent->cg_children == 2) { 9732668bb2aSAlexander Motin if (cg == &parent->cg_child[0]) 9742668bb2aSAlexander Motin cg = &parent->cg_child[1]; 9752668bb2aSAlexander Motin else 9762668bb2aSAlexander Motin cg = &parent->cg_child[0]; 9772668bb2aSAlexander Motin goup = 1; 9782668bb2aSAlexander Motin } else 9792668bb2aSAlexander Motin cg = parent; 98080f86c9fSJeff Roberson continue; 9817b8bfa0dSJeff Roberson } 9827b8bfa0dSJeff Roberson steal = TDQ_CPU(cpu); 98397e9382dSDon Lewis /* 98497e9382dSDon Lewis * The data returned by sched_highest() is stale and 98597e9382dSDon Lewis * the chosen CPU no longer has an eligible thread. 98697e9382dSDon Lewis * 98797e9382dSDon Lewis * Testing this ahead of tdq_lock_pair() only catches 98897e9382dSDon Lewis * this situation about 20% of the time on an 8 core 98997e9382dSDon Lewis * 16 thread Ryzen 7, but it still helps performance. 99097e9382dSDon Lewis */ 99197e9382dSDon Lewis if (steal->tdq_load < steal_thresh || 99297e9382dSDon Lewis steal->tdq_transferable == 0) 99397e9382dSDon Lewis goto restart; 99497e9382dSDon Lewis /* 995*8bb173fbSAlexander Motin * Try to lock both queues. If we are assigned a thread while 996*8bb173fbSAlexander Motin * waited for the lock, switch to it now instead of stealing. 997*8bb173fbSAlexander Motin * If we can't get the lock, then somebody likely got there 998*8bb173fbSAlexander Motin * first so continue searching. 99997e9382dSDon Lewis */ 1000*8bb173fbSAlexander Motin TDQ_LOCK(tdq); 1001*8bb173fbSAlexander Motin if (tdq->tdq_load > 0) { 1002*8bb173fbSAlexander Motin mi_switch(SW_VOL | SWT_IDLE); 1003*8bb173fbSAlexander Motin return (0); 1004*8bb173fbSAlexander Motin } 1005*8bb173fbSAlexander Motin if (TDQ_TRYLOCK_FLAGS(steal, MTX_DUPOK) == 0) { 1006*8bb173fbSAlexander Motin TDQ_UNLOCK(tdq); 1007*8bb173fbSAlexander Motin CPU_CLR(cpu, &mask); 1008*8bb173fbSAlexander Motin continue; 1009*8bb173fbSAlexander Motin } 101097e9382dSDon Lewis /* 101197e9382dSDon Lewis * The data returned by sched_highest() is stale and 101297e9382dSDon Lewis * the chosen CPU no longer has an eligible thread, or 101397e9382dSDon Lewis * we were preempted and the CPU loading info may be out 101497e9382dSDon Lewis * of date. The latter is rare. In either case restart 101597e9382dSDon Lewis * the search. 101697e9382dSDon Lewis */ 101797e9382dSDon Lewis if (steal->tdq_load < steal_thresh || 101897e9382dSDon Lewis steal->tdq_transferable == 0 || 101997e9382dSDon Lewis switchcnt != tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt) { 10207fcf154aSJeff Roberson tdq_unlock_pair(tdq, steal); 102197e9382dSDon Lewis goto restart; 102262fa74d9SJeff Roberson } 102362fa74d9SJeff Roberson /* 102497e9382dSDon Lewis * Steal the thread and switch to it. 102562fa74d9SJeff Roberson */ 102697e9382dSDon Lewis if (tdq_move(steal, tdq) != NULL) 102797e9382dSDon Lewis break; 102897e9382dSDon Lewis /* 102997e9382dSDon Lewis * We failed to acquire a thread even though it looked 103097e9382dSDon Lewis * like one was available. This could be due to affinity 103197e9382dSDon Lewis * restrictions or for other reasons. Loop again after 103297e9382dSDon Lewis * removing this CPU from the set. The restart logic 103397e9382dSDon Lewis * above does not restore this CPU to the set due to the 103497e9382dSDon Lewis * likelyhood of failing here again. 103597e9382dSDon Lewis */ 103697e9382dSDon Lewis CPU_CLR(cpu, &mask); 103762fa74d9SJeff Roberson tdq_unlock_pair(tdq, steal); 103880f86c9fSJeff Roberson } 1039ae7a6b38SJeff Roberson TDQ_UNLOCK(steal); 1040686bcb5cSJeff Roberson mi_switch(SW_VOL | SWT_IDLE); 10417b8bfa0dSJeff Roberson return (0); 104222bf7d9aSJeff Roberson } 104322bf7d9aSJeff Roberson 1044ae7a6b38SJeff Roberson /* 1045ae7a6b38SJeff Roberson * Notify a remote cpu of new work. Sends an IPI if criteria are met. 1046ae7a6b38SJeff Roberson */ 104722bf7d9aSJeff Roberson static void 104827ee18adSRyan Stone tdq_notify(struct tdq *tdq, struct thread *td) 104922bf7d9aSJeff Roberson { 105002f0ff6dSJohn Baldwin struct thread *ctd; 105127ee18adSRyan Stone int pri; 10527b8bfa0dSJeff Roberson int cpu; 105322bf7d9aSJeff Roberson 10547789ab32SMark Johnston if (tdq->tdq_owepreempt) 1055ff256d9cSJeff Roberson return; 105627ee18adSRyan Stone cpu = td_get_sched(td)->ts_cpu; 105727ee18adSRyan Stone pri = td->td_priority; 105802f0ff6dSJohn Baldwin ctd = pcpu_find(cpu)->pc_curthread; 105902f0ff6dSJohn Baldwin if (!sched_shouldpreempt(pri, ctd->td_priority, 1)) 10606b2f763fSJeff Roberson return; 106179654969SAlexander Motin 106279654969SAlexander Motin /* 1063ae9e9b4fSAlexander Motin * Make sure that our caller's earlier update to tdq_load is 1064ae9e9b4fSAlexander Motin * globally visible before we read tdq_cpu_idle. Idle thread 106579654969SAlexander Motin * accesses both of them without locks, and the order is important. 106679654969SAlexander Motin */ 1067e8677f38SKonstantin Belousov atomic_thread_fence_seq_cst(); 106879654969SAlexander Motin 106902f0ff6dSJohn Baldwin if (TD_IS_IDLETHREAD(ctd)) { 10701690c6c1SJeff Roberson /* 10716c47aaaeSJeff Roberson * If the MD code has an idle wakeup routine try that before 10726c47aaaeSJeff Roberson * falling back to IPI. 10736c47aaaeSJeff Roberson */ 10749f9ad565SAlexander Motin if (!tdq->tdq_cpu_idle || cpu_idle_wakeup(cpu)) 10756c47aaaeSJeff Roberson return; 10761690c6c1SJeff Roberson } 10777789ab32SMark Johnston 10787789ab32SMark Johnston /* 10797789ab32SMark Johnston * The run queues have been updated, so any switch on the remote CPU 10807789ab32SMark Johnston * will satisfy the preemption request. 10817789ab32SMark Johnston */ 10827789ab32SMark Johnston tdq->tdq_owepreempt = 1; 1083d9d8d144SJohn Baldwin ipi_cpu(cpu, IPI_PREEMPT); 108422bf7d9aSJeff Roberson } 108522bf7d9aSJeff Roberson 1086ae7a6b38SJeff Roberson /* 1087ae7a6b38SJeff Roberson * Steals load from a timeshare queue. Honors the rotating queue head 1088ae7a6b38SJeff Roberson * index. 1089ae7a6b38SJeff Roberson */ 10909727e637SJeff Roberson static struct thread * 109162fa74d9SJeff Roberson runq_steal_from(struct runq *rq, int cpu, u_char start) 1092ae7a6b38SJeff Roberson { 1093ae7a6b38SJeff Roberson struct rqbits *rqb; 1094ae7a6b38SJeff Roberson struct rqhead *rqh; 109536acfc65SAlexander Motin struct thread *td, *first; 1096ae7a6b38SJeff Roberson int bit; 1097ae7a6b38SJeff Roberson int i; 1098ae7a6b38SJeff Roberson 1099ae7a6b38SJeff Roberson rqb = &rq->rq_status; 1100ae7a6b38SJeff Roberson bit = start & (RQB_BPW -1); 110136acfc65SAlexander Motin first = NULL; 1102ae7a6b38SJeff Roberson again: 1103ae7a6b38SJeff Roberson for (i = RQB_WORD(start); i < RQB_LEN; bit = 0, i++) { 1104ae7a6b38SJeff Roberson if (rqb->rqb_bits[i] == 0) 1105ae7a6b38SJeff Roberson continue; 11068bc713f6SJeff Roberson if (bit == 0) 11078bc713f6SJeff Roberson bit = RQB_FFS(rqb->rqb_bits[i]); 11088bc713f6SJeff Roberson for (; bit < RQB_BPW; bit++) { 11098bc713f6SJeff Roberson if ((rqb->rqb_bits[i] & (1ul << bit)) == 0) 1110ae7a6b38SJeff Roberson continue; 11118bc713f6SJeff Roberson rqh = &rq->rq_queues[bit + (i << RQB_L2BPW)]; 11129727e637SJeff Roberson TAILQ_FOREACH(td, rqh, td_runq) { 11139727e637SJeff Roberson if (first && THREAD_CAN_MIGRATE(td) && 11149727e637SJeff Roberson THREAD_CAN_SCHED(td, cpu)) 11159727e637SJeff Roberson return (td); 111636acfc65SAlexander Motin first = td; 1117ae7a6b38SJeff Roberson } 1118ae7a6b38SJeff Roberson } 11198bc713f6SJeff Roberson } 1120ae7a6b38SJeff Roberson if (start != 0) { 1121ae7a6b38SJeff Roberson start = 0; 1122ae7a6b38SJeff Roberson goto again; 1123ae7a6b38SJeff Roberson } 1124ae7a6b38SJeff Roberson 112536acfc65SAlexander Motin if (first && THREAD_CAN_MIGRATE(first) && 112636acfc65SAlexander Motin THREAD_CAN_SCHED(first, cpu)) 112736acfc65SAlexander Motin return (first); 1128ae7a6b38SJeff Roberson return (NULL); 1129ae7a6b38SJeff Roberson } 1130ae7a6b38SJeff Roberson 1131ae7a6b38SJeff Roberson /* 1132ae7a6b38SJeff Roberson * Steals load from a standard linear queue. 1133ae7a6b38SJeff Roberson */ 11349727e637SJeff Roberson static struct thread * 113562fa74d9SJeff Roberson runq_steal(struct runq *rq, int cpu) 113622bf7d9aSJeff Roberson { 113722bf7d9aSJeff Roberson struct rqhead *rqh; 113822bf7d9aSJeff Roberson struct rqbits *rqb; 11399727e637SJeff Roberson struct thread *td; 114022bf7d9aSJeff Roberson int word; 114122bf7d9aSJeff Roberson int bit; 114222bf7d9aSJeff Roberson 114322bf7d9aSJeff Roberson rqb = &rq->rq_status; 114422bf7d9aSJeff Roberson for (word = 0; word < RQB_LEN; word++) { 114522bf7d9aSJeff Roberson if (rqb->rqb_bits[word] == 0) 114622bf7d9aSJeff Roberson continue; 114722bf7d9aSJeff Roberson for (bit = 0; bit < RQB_BPW; bit++) { 1148a2640c9bSPeter Wemm if ((rqb->rqb_bits[word] & (1ul << bit)) == 0) 114922bf7d9aSJeff Roberson continue; 115022bf7d9aSJeff Roberson rqh = &rq->rq_queues[bit + (word << RQB_L2BPW)]; 11519727e637SJeff Roberson TAILQ_FOREACH(td, rqh, td_runq) 11529727e637SJeff Roberson if (THREAD_CAN_MIGRATE(td) && 11539727e637SJeff Roberson THREAD_CAN_SCHED(td, cpu)) 11549727e637SJeff Roberson return (td); 115522bf7d9aSJeff Roberson } 115622bf7d9aSJeff Roberson } 115722bf7d9aSJeff Roberson return (NULL); 115822bf7d9aSJeff Roberson } 115922bf7d9aSJeff Roberson 1160ae7a6b38SJeff Roberson /* 1161ae7a6b38SJeff Roberson * Attempt to steal a thread in priority order from a thread queue. 1162ae7a6b38SJeff Roberson */ 11639727e637SJeff Roberson static struct thread * 116462fa74d9SJeff Roberson tdq_steal(struct tdq *tdq, int cpu) 116522bf7d9aSJeff Roberson { 11669727e637SJeff Roberson struct thread *td; 116722bf7d9aSJeff Roberson 1168ae7a6b38SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED); 11699727e637SJeff Roberson if ((td = runq_steal(&tdq->tdq_realtime, cpu)) != NULL) 11709727e637SJeff Roberson return (td); 11719727e637SJeff Roberson if ((td = runq_steal_from(&tdq->tdq_timeshare, 11729727e637SJeff Roberson cpu, tdq->tdq_ridx)) != NULL) 11739727e637SJeff Roberson return (td); 117462fa74d9SJeff Roberson return (runq_steal(&tdq->tdq_idle, cpu)); 117522bf7d9aSJeff Roberson } 117680f86c9fSJeff Roberson 1177ae7a6b38SJeff Roberson /* 1178ae7a6b38SJeff Roberson * Sets the thread lock and ts_cpu to match the requested cpu. Unlocks the 11797fcf154aSJeff Roberson * current lock and returns with the assigned queue locked. 1180ae7a6b38SJeff Roberson */ 1181ae7a6b38SJeff Roberson static inline struct tdq * 11829727e637SJeff Roberson sched_setcpu(struct thread *td, int cpu, int flags) 118380f86c9fSJeff Roberson { 11849727e637SJeff Roberson 1185ae7a6b38SJeff Roberson struct tdq *tdq; 118661a74c5cSJeff Roberson struct mtx *mtx; 118780f86c9fSJeff Roberson 11889727e637SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 1189ae7a6b38SJeff Roberson tdq = TDQ_CPU(cpu); 119093ccd6bfSKonstantin Belousov td_get_sched(td)->ts_cpu = cpu; 11919727e637SJeff Roberson /* 11929727e637SJeff Roberson * If the lock matches just return the queue. 11939727e637SJeff Roberson */ 119461a74c5cSJeff Roberson if (td->td_lock == TDQ_LOCKPTR(tdq)) { 119561a74c5cSJeff Roberson KASSERT((flags & SRQ_HOLD) == 0, 119661a74c5cSJeff Roberson ("sched_setcpu: Invalid lock for SRQ_HOLD")); 1197ae7a6b38SJeff Roberson return (tdq); 1198ae7a6b38SJeff Roberson } 119961a74c5cSJeff Roberson 120080f86c9fSJeff Roberson /* 1201ae7a6b38SJeff Roberson * The hard case, migration, we need to block the thread first to 1202ae7a6b38SJeff Roberson * prevent order reversals with other cpus locks. 12037b8bfa0dSJeff Roberson */ 1204b0b9dee5SAttilio Rao spinlock_enter(); 120561a74c5cSJeff Roberson mtx = thread_lock_block(td); 120661a74c5cSJeff Roberson if ((flags & SRQ_HOLD) == 0) 120761a74c5cSJeff Roberson mtx_unlock_spin(mtx); 1208ae7a6b38SJeff Roberson TDQ_LOCK(tdq); 1209ae7a6b38SJeff Roberson thread_lock_unblock(td, TDQ_LOCKPTR(tdq)); 1210b0b9dee5SAttilio Rao spinlock_exit(); 1211ae7a6b38SJeff Roberson return (tdq); 121280f86c9fSJeff Roberson } 12132454aaf5SJeff Roberson 12148df78c41SJeff Roberson SCHED_STAT_DEFINE(pickcpu_intrbind, "Soft interrupt binding"); 12158df78c41SJeff Roberson SCHED_STAT_DEFINE(pickcpu_idle_affinity, "Picked idle cpu based on affinity"); 12168df78c41SJeff Roberson SCHED_STAT_DEFINE(pickcpu_affinity, "Picked cpu based on affinity"); 12178df78c41SJeff Roberson SCHED_STAT_DEFINE(pickcpu_lowest, "Selected lowest load"); 12188df78c41SJeff Roberson SCHED_STAT_DEFINE(pickcpu_local, "Migrated to current cpu"); 12198df78c41SJeff Roberson SCHED_STAT_DEFINE(pickcpu_migration, "Selection may have caused migration"); 12208df78c41SJeff Roberson 1221ae7a6b38SJeff Roberson static int 12229727e637SJeff Roberson sched_pickcpu(struct thread *td, int flags) 1223ae7a6b38SJeff Roberson { 122436acfc65SAlexander Motin struct cpu_group *cg, *ccg; 12259727e637SJeff Roberson struct td_sched *ts; 1226ae7a6b38SJeff Roberson struct tdq *tdq; 1227aefe0a8cSAlexander Motin cpuset_t *mask; 1228c9205e35SAlexander Motin int cpu, pri, self, intr; 12297b8bfa0dSJeff Roberson 123062fa74d9SJeff Roberson self = PCPU_GET(cpuid); 123193ccd6bfSKonstantin Belousov ts = td_get_sched(td); 1232efe67753SNathan Whitehorn KASSERT(!CPU_ABSENT(ts->ts_cpu), ("sched_pickcpu: Start scheduler on " 1233efe67753SNathan Whitehorn "absent CPU %d for thread %s.", ts->ts_cpu, td->td_name)); 12347b8bfa0dSJeff Roberson if (smp_started == 0) 12357b8bfa0dSJeff Roberson return (self); 123628994a58SJeff Roberson /* 123728994a58SJeff Roberson * Don't migrate a running thread from sched_switch(). 123828994a58SJeff Roberson */ 123962fa74d9SJeff Roberson if ((flags & SRQ_OURSELF) || !THREAD_CAN_MIGRATE(td)) 124062fa74d9SJeff Roberson return (ts->ts_cpu); 12417b8bfa0dSJeff Roberson /* 124262fa74d9SJeff Roberson * Prefer to run interrupt threads on the processors that generate 124362fa74d9SJeff Roberson * the interrupt. 12447b8bfa0dSJeff Roberson */ 124562fa74d9SJeff Roberson if (td->td_priority <= PRI_MAX_ITHD && THREAD_CAN_SCHED(td, self) && 1246c9205e35SAlexander Motin curthread->td_intr_nesting_level) { 1247c55dc51cSAlexander Motin tdq = TDQ_SELF(); 1248c55dc51cSAlexander Motin if (tdq->tdq_lowpri >= PRI_MIN_IDLE) { 1249c55dc51cSAlexander Motin SCHED_STAT_INC(pickcpu_idle_affinity); 1250c55dc51cSAlexander Motin return (self); 1251c55dc51cSAlexander Motin } 125262fa74d9SJeff Roberson ts->ts_cpu = self; 1253c9205e35SAlexander Motin intr = 1; 1254c55dc51cSAlexander Motin cg = tdq->tdq_cg; 1255c55dc51cSAlexander Motin goto llc; 1256c55dc51cSAlexander Motin } else { 1257c9205e35SAlexander Motin intr = 0; 1258c55dc51cSAlexander Motin tdq = TDQ_CPU(ts->ts_cpu); 1259c55dc51cSAlexander Motin cg = tdq->tdq_cg; 1260c55dc51cSAlexander Motin } 12617b8bfa0dSJeff Roberson /* 126236acfc65SAlexander Motin * If the thread can run on the last cpu and the affinity has not 12630127914cSEric van Gyzen * expired and it is idle, run it there. 12647b8bfa0dSJeff Roberson */ 126536acfc65SAlexander Motin if (THREAD_CAN_SCHED(td, ts->ts_cpu) && 126636acfc65SAlexander Motin tdq->tdq_lowpri >= PRI_MIN_IDLE && 126736acfc65SAlexander Motin SCHED_AFFINITY(ts, CG_SHARE_L2)) { 1268c55dc51cSAlexander Motin if (cg->cg_flags & CG_FLAG_THREAD) { 1269176dd236SAlexander Motin /* Check all SMT threads for being idle. */ 1270aefe0a8cSAlexander Motin for (cpu = cg->cg_first; cpu <= cg->cg_last; cpu++) { 1271176dd236SAlexander Motin if (CPU_ISSET(cpu, &cg->cg_mask) && 1272176dd236SAlexander Motin TDQ_CPU(cpu)->tdq_lowpri < PRI_MIN_IDLE) 127362fa74d9SJeff Roberson break; 1274aefe0a8cSAlexander Motin } 1275aefe0a8cSAlexander Motin if (cpu > cg->cg_last) { 1276176dd236SAlexander Motin SCHED_STAT_INC(pickcpu_idle_affinity); 1277176dd236SAlexander Motin return (ts->ts_cpu); 127836acfc65SAlexander Motin } 1279176dd236SAlexander Motin } else { 128036acfc65SAlexander Motin SCHED_STAT_INC(pickcpu_idle_affinity); 128136acfc65SAlexander Motin return (ts->ts_cpu); 128236acfc65SAlexander Motin } 128336acfc65SAlexander Motin } 1284c55dc51cSAlexander Motin llc: 128536acfc65SAlexander Motin /* 128636acfc65SAlexander Motin * Search for the last level cache CPU group in the tree. 1287c9205e35SAlexander Motin * Skip SMT, identical groups and caches with expired affinity. 1288c9205e35SAlexander Motin * Interrupt threads affinity is explicit and never expires. 128936acfc65SAlexander Motin */ 129036acfc65SAlexander Motin for (ccg = NULL; cg != NULL; cg = cg->cg_parent) { 129136acfc65SAlexander Motin if (cg->cg_flags & CG_FLAG_THREAD) 129236acfc65SAlexander Motin continue; 1293c9205e35SAlexander Motin if (cg->cg_children == 1 || cg->cg_count == 1) 1294c9205e35SAlexander Motin continue; 1295c9205e35SAlexander Motin if (cg->cg_level == CG_SHARE_NONE || 1296c9205e35SAlexander Motin (!intr && !SCHED_AFFINITY(ts, cg->cg_level))) 129736acfc65SAlexander Motin continue; 129836acfc65SAlexander Motin ccg = cg; 129936acfc65SAlexander Motin } 1300c9205e35SAlexander Motin /* Found LLC shared by all CPUs, so do a global search. */ 1301c9205e35SAlexander Motin if (ccg == cpu_top) 1302c9205e35SAlexander Motin ccg = NULL; 130362fa74d9SJeff Roberson cpu = -1; 1304aefe0a8cSAlexander Motin mask = &td->td_cpuset->cs_mask; 1305c9205e35SAlexander Motin pri = td->td_priority; 1306c9205e35SAlexander Motin /* 1307c9205e35SAlexander Motin * Try hard to keep interrupts within found LLC. Search the LLC for 1308c9205e35SAlexander Motin * the least loaded CPU we can run now. For NUMA systems it should 1309c9205e35SAlexander Motin * be within target domain, and it also reduces scheduling overhead. 1310c9205e35SAlexander Motin */ 1311c9205e35SAlexander Motin if (ccg != NULL && intr) { 1312c9205e35SAlexander Motin cpu = sched_lowest(ccg, mask, pri, INT_MAX, ts->ts_cpu); 1313c9205e35SAlexander Motin if (cpu >= 0) 1314c9205e35SAlexander Motin SCHED_STAT_INC(pickcpu_intrbind); 1315c9205e35SAlexander Motin } else 1316c9205e35SAlexander Motin /* Search the LLC for the least loaded idle CPU we can run now. */ 1317c9205e35SAlexander Motin if (ccg != NULL) { 1318c9205e35SAlexander Motin cpu = sched_lowest(ccg, mask, max(pri, PRI_MAX_TIMESHARE), 131936acfc65SAlexander Motin INT_MAX, ts->ts_cpu); 1320c9205e35SAlexander Motin if (cpu >= 0) 1321c9205e35SAlexander Motin SCHED_STAT_INC(pickcpu_affinity); 1322c9205e35SAlexander Motin } 1323c9205e35SAlexander Motin /* Search globally for the least loaded CPU we can run now. */ 1324c9205e35SAlexander Motin if (cpu < 0) { 132536acfc65SAlexander Motin cpu = sched_lowest(cpu_top, mask, pri, INT_MAX, ts->ts_cpu); 1326c9205e35SAlexander Motin if (cpu >= 0) 1327c9205e35SAlexander Motin SCHED_STAT_INC(pickcpu_lowest); 1328c9205e35SAlexander Motin } 1329c9205e35SAlexander Motin /* Search globally for the least loaded CPU. */ 1330c9205e35SAlexander Motin if (cpu < 0) { 133136acfc65SAlexander Motin cpu = sched_lowest(cpu_top, mask, -1, INT_MAX, ts->ts_cpu); 1332c9205e35SAlexander Motin if (cpu >= 0) 1333c9205e35SAlexander Motin SCHED_STAT_INC(pickcpu_lowest); 1334c9205e35SAlexander Motin } 1335bb3dfc6aSAlexander Motin KASSERT(cpu >= 0, ("sched_pickcpu: Failed to find a cpu.")); 1336efe67753SNathan Whitehorn KASSERT(!CPU_ABSENT(cpu), ("sched_pickcpu: Picked absent CPU %d.", cpu)); 133762fa74d9SJeff Roberson /* 133862fa74d9SJeff Roberson * Compare the lowest loaded cpu to current cpu. 133962fa74d9SJeff Roberson */ 1340018ff686SJeff Roberson tdq = TDQ_CPU(cpu); 1341018ff686SJeff Roberson if (THREAD_CAN_SCHED(td, self) && TDQ_SELF()->tdq_lowpri > pri && 1342018ff686SJeff Roberson tdq->tdq_lowpri < PRI_MIN_IDLE && 1343018ff686SJeff Roberson TDQ_SELF()->tdq_load <= tdq->tdq_load + 1) { 13448df78c41SJeff Roberson SCHED_STAT_INC(pickcpu_local); 134562fa74d9SJeff Roberson cpu = self; 1346c9205e35SAlexander Motin } 13478df78c41SJeff Roberson if (cpu != ts->ts_cpu) 13488df78c41SJeff Roberson SCHED_STAT_INC(pickcpu_migration); 1349ae7a6b38SJeff Roberson return (cpu); 135080f86c9fSJeff Roberson } 135162fa74d9SJeff Roberson #endif 135222bf7d9aSJeff Roberson 135322bf7d9aSJeff Roberson /* 135422bf7d9aSJeff Roberson * Pick the highest priority task we have and return it. 13550c0a98b2SJeff Roberson */ 13569727e637SJeff Roberson static struct thread * 1357ad1e7d28SJulian Elischer tdq_choose(struct tdq *tdq) 13585d7ef00cSJeff Roberson { 13599727e637SJeff Roberson struct thread *td; 13605d7ef00cSJeff Roberson 1361ae7a6b38SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED); 13629727e637SJeff Roberson td = runq_choose(&tdq->tdq_realtime); 13639727e637SJeff Roberson if (td != NULL) 13649727e637SJeff Roberson return (td); 13659727e637SJeff Roberson td = runq_choose_from(&tdq->tdq_timeshare, tdq->tdq_ridx); 13669727e637SJeff Roberson if (td != NULL) { 136712d56c0fSJohn Baldwin KASSERT(td->td_priority >= PRI_MIN_BATCH, 1368e7d50326SJeff Roberson ("tdq_choose: Invalid priority on timeshare queue %d", 13699727e637SJeff Roberson td->td_priority)); 13709727e637SJeff Roberson return (td); 137115dc847eSJeff Roberson } 13729727e637SJeff Roberson td = runq_choose(&tdq->tdq_idle); 13739727e637SJeff Roberson if (td != NULL) { 13749727e637SJeff Roberson KASSERT(td->td_priority >= PRI_MIN_IDLE, 1375e7d50326SJeff Roberson ("tdq_choose: Invalid priority on idle queue %d", 13769727e637SJeff Roberson td->td_priority)); 13779727e637SJeff Roberson return (td); 1378e7d50326SJeff Roberson } 1379e7d50326SJeff Roberson 1380e7d50326SJeff Roberson return (NULL); 1381245f3abfSJeff Roberson } 13820a016a05SJeff Roberson 1383ae7a6b38SJeff Roberson /* 1384ae7a6b38SJeff Roberson * Initialize a thread queue. 1385ae7a6b38SJeff Roberson */ 13860a016a05SJeff Roberson static void 1387018ff686SJeff Roberson tdq_setup(struct tdq *tdq, int id) 13880a016a05SJeff Roberson { 1389ae7a6b38SJeff Roberson 1390c47f202bSJeff Roberson if (bootverbose) 1391018ff686SJeff Roberson printf("ULE: setup cpu %d\n", id); 1392e7d50326SJeff Roberson runq_init(&tdq->tdq_realtime); 1393e7d50326SJeff Roberson runq_init(&tdq->tdq_timeshare); 1394d2ad694cSJeff Roberson runq_init(&tdq->tdq_idle); 1395018ff686SJeff Roberson tdq->tdq_id = id; 139662fa74d9SJeff Roberson snprintf(tdq->tdq_name, sizeof(tdq->tdq_name), 139762fa74d9SJeff Roberson "sched lock %d", (int)TDQ_ID(tdq)); 139861a74c5cSJeff Roberson mtx_init(&tdq->tdq_lock, tdq->tdq_name, "sched lock", MTX_SPIN); 13998f51ad55SJeff Roberson #ifdef KTR 14008f51ad55SJeff Roberson snprintf(tdq->tdq_loadname, sizeof(tdq->tdq_loadname), 14018f51ad55SJeff Roberson "CPU %d load", (int)TDQ_ID(tdq)); 14028f51ad55SJeff Roberson #endif 14030a016a05SJeff Roberson } 14040a016a05SJeff Roberson 1405c47f202bSJeff Roberson #ifdef SMP 1406c47f202bSJeff Roberson static void 1407c47f202bSJeff Roberson sched_setup_smp(void) 1408c47f202bSJeff Roberson { 1409c47f202bSJeff Roberson struct tdq *tdq; 1410c47f202bSJeff Roberson int i; 1411c47f202bSJeff Roberson 141262fa74d9SJeff Roberson cpu_top = smp_topo(); 14133aa6d94eSJohn Baldwin CPU_FOREACH(i) { 1414018ff686SJeff Roberson tdq = DPCPU_ID_PTR(i, tdq); 1415018ff686SJeff Roberson tdq_setup(tdq, i); 141662fa74d9SJeff Roberson tdq->tdq_cg = smp_topo_find(cpu_top, i); 141762fa74d9SJeff Roberson if (tdq->tdq_cg == NULL) 141862fa74d9SJeff Roberson panic("Can't find cpu group for %d\n", i); 1419c47f202bSJeff Roberson } 1420018ff686SJeff Roberson PCPU_SET(sched, DPCPU_PTR(tdq)); 142162fa74d9SJeff Roberson balance_tdq = TDQ_SELF(); 1422c47f202bSJeff Roberson } 1423c47f202bSJeff Roberson #endif 1424c47f202bSJeff Roberson 1425ae7a6b38SJeff Roberson /* 1426ae7a6b38SJeff Roberson * Setup the thread queues and initialize the topology based on MD 1427ae7a6b38SJeff Roberson * information. 1428ae7a6b38SJeff Roberson */ 142935e6168fSJeff Roberson static void 143035e6168fSJeff Roberson sched_setup(void *dummy) 143135e6168fSJeff Roberson { 1432ae7a6b38SJeff Roberson struct tdq *tdq; 1433c47f202bSJeff Roberson 14340ec896fdSJeff Roberson #ifdef SMP 1435c47f202bSJeff Roberson sched_setup_smp(); 1436749d01b0SJeff Roberson #else 1437018ff686SJeff Roberson tdq_setup(TDQ_SELF(), 0); 1438356500a3SJeff Roberson #endif 1439018ff686SJeff Roberson tdq = TDQ_SELF(); 1440ae7a6b38SJeff Roberson 1441ae7a6b38SJeff Roberson /* Add thread0's load since it's running. */ 1442ae7a6b38SJeff Roberson TDQ_LOCK(tdq); 1443e1504695SJeff Roberson thread0.td_lock = TDQ_LOCKPTR(tdq); 14449727e637SJeff Roberson tdq_load_add(tdq, &thread0); 144562fa74d9SJeff Roberson tdq->tdq_lowpri = thread0.td_priority; 1446ae7a6b38SJeff Roberson TDQ_UNLOCK(tdq); 144735e6168fSJeff Roberson } 144835e6168fSJeff Roberson 1449ae7a6b38SJeff Roberson /* 1450579895dfSAlexander Motin * This routine determines time constants after stathz and hz are setup. 1451ae7a6b38SJeff Roberson */ 1452a1d4fe69SDavid Xu /* ARGSUSED */ 1453a1d4fe69SDavid Xu static void 1454a1d4fe69SDavid Xu sched_initticks(void *dummy) 1455a1d4fe69SDavid Xu { 1456ae7a6b38SJeff Roberson int incr; 1457ae7a6b38SJeff Roberson 1458a1d4fe69SDavid Xu realstathz = stathz ? stathz : hz; 14595e5c3873SJeff Roberson sched_slice = realstathz / SCHED_SLICE_DEFAULT_DIVISOR; 14605e5c3873SJeff Roberson sched_slice_min = sched_slice / SCHED_SLICE_MIN_DIVISOR; 146137f4e025SAlexander Motin hogticks = imax(1, (2 * hz * sched_slice + realstathz / 2) / 146237f4e025SAlexander Motin realstathz); 1463a1d4fe69SDavid Xu 1464a1d4fe69SDavid Xu /* 1465e7d50326SJeff Roberson * tickincr is shifted out by 10 to avoid rounding errors due to 14663f872f85SJeff Roberson * hz not being evenly divisible by stathz on all platforms. 1467e7d50326SJeff Roberson */ 1468ae7a6b38SJeff Roberson incr = (hz << SCHED_TICK_SHIFT) / realstathz; 1469e7d50326SJeff Roberson /* 1470e7d50326SJeff Roberson * This does not work for values of stathz that are more than 1471e7d50326SJeff Roberson * 1 << SCHED_TICK_SHIFT * hz. In practice this does not happen. 1472a1d4fe69SDavid Xu */ 1473ae7a6b38SJeff Roberson if (incr == 0) 1474ae7a6b38SJeff Roberson incr = 1; 1475ae7a6b38SJeff Roberson tickincr = incr; 14767b8bfa0dSJeff Roberson #ifdef SMP 14779862717aSJeff Roberson /* 14787fcf154aSJeff Roberson * Set the default balance interval now that we know 14797fcf154aSJeff Roberson * what realstathz is. 14807fcf154aSJeff Roberson */ 14817fcf154aSJeff Roberson balance_interval = realstathz; 1482290d9060SDon Lewis balance_ticks = balance_interval; 14837b8bfa0dSJeff Roberson affinity = SCHED_AFFINITY_DEFAULT; 14847b8bfa0dSJeff Roberson #endif 1485b3f40a41SAlexander Motin if (sched_idlespinthresh < 0) 14862c27cb3aSAlexander Motin sched_idlespinthresh = 2 * max(10000, 6 * hz) / realstathz; 1487a1d4fe69SDavid Xu } 1488a1d4fe69SDavid Xu 148935e6168fSJeff Roberson /* 1490ae7a6b38SJeff Roberson * This is the core of the interactivity algorithm. Determines a score based 1491ae7a6b38SJeff Roberson * on past behavior. It is the ratio of sleep time to run time scaled to 1492ae7a6b38SJeff Roberson * a [0, 100] integer. This is the voluntary sleep time of a process, which 1493ae7a6b38SJeff Roberson * differs from the cpu usage because it does not account for time spent 1494ae7a6b38SJeff Roberson * waiting on a run-queue. Would be prettier if we had floating point. 149557031f79SGeorge V. Neville-Neil * 149657031f79SGeorge V. Neville-Neil * When a thread's sleep time is greater than its run time the 149757031f79SGeorge V. Neville-Neil * calculation is: 149857031f79SGeorge V. Neville-Neil * 149957031f79SGeorge V. Neville-Neil * scaling factor 150057031f79SGeorge V. Neville-Neil * interactivity score = --------------------- 150157031f79SGeorge V. Neville-Neil * sleep time / run time 150257031f79SGeorge V. Neville-Neil * 150357031f79SGeorge V. Neville-Neil * 150457031f79SGeorge V. Neville-Neil * When a thread's run time is greater than its sleep time the 150557031f79SGeorge V. Neville-Neil * calculation is: 150657031f79SGeorge V. Neville-Neil * 150757031f79SGeorge V. Neville-Neil * scaling factor 150843521b46Swiklam * interactivity score = 2 * scaling factor - --------------------- 150957031f79SGeorge V. Neville-Neil * run time / sleep time 1510ae7a6b38SJeff Roberson */ 1511ae7a6b38SJeff Roberson static int 1512ae7a6b38SJeff Roberson sched_interact_score(struct thread *td) 1513ae7a6b38SJeff Roberson { 1514ae7a6b38SJeff Roberson struct td_sched *ts; 1515ae7a6b38SJeff Roberson int div; 1516ae7a6b38SJeff Roberson 151793ccd6bfSKonstantin Belousov ts = td_get_sched(td); 1518ae7a6b38SJeff Roberson /* 1519ae7a6b38SJeff Roberson * The score is only needed if this is likely to be an interactive 1520ae7a6b38SJeff Roberson * task. Don't go through the expense of computing it if there's 1521ae7a6b38SJeff Roberson * no chance. 1522ae7a6b38SJeff Roberson */ 1523ae7a6b38SJeff Roberson if (sched_interact <= SCHED_INTERACT_HALF && 1524ae7a6b38SJeff Roberson ts->ts_runtime >= ts->ts_slptime) 1525ae7a6b38SJeff Roberson return (SCHED_INTERACT_HALF); 1526ae7a6b38SJeff Roberson 1527ae7a6b38SJeff Roberson if (ts->ts_runtime > ts->ts_slptime) { 1528ae7a6b38SJeff Roberson div = max(1, ts->ts_runtime / SCHED_INTERACT_HALF); 1529ae7a6b38SJeff Roberson return (SCHED_INTERACT_HALF + 1530ae7a6b38SJeff Roberson (SCHED_INTERACT_HALF - (ts->ts_slptime / div))); 1531ae7a6b38SJeff Roberson } 1532ae7a6b38SJeff Roberson if (ts->ts_slptime > ts->ts_runtime) { 1533ae7a6b38SJeff Roberson div = max(1, ts->ts_slptime / SCHED_INTERACT_HALF); 1534ae7a6b38SJeff Roberson return (ts->ts_runtime / div); 1535ae7a6b38SJeff Roberson } 1536ae7a6b38SJeff Roberson /* runtime == slptime */ 1537ae7a6b38SJeff Roberson if (ts->ts_runtime) 1538ae7a6b38SJeff Roberson return (SCHED_INTERACT_HALF); 1539ae7a6b38SJeff Roberson 1540ae7a6b38SJeff Roberson /* 1541ae7a6b38SJeff Roberson * This can happen if slptime and runtime are 0. 1542ae7a6b38SJeff Roberson */ 1543ae7a6b38SJeff Roberson return (0); 1544ae7a6b38SJeff Roberson 1545ae7a6b38SJeff Roberson } 1546ae7a6b38SJeff Roberson 1547ae7a6b38SJeff Roberson /* 154835e6168fSJeff Roberson * Scale the scheduling priority according to the "interactivity" of this 154935e6168fSJeff Roberson * process. 155035e6168fSJeff Roberson */ 155115dc847eSJeff Roberson static void 15528460a577SJohn Birrell sched_priority(struct thread *td) 155335e6168fSJeff Roberson { 1554e7d50326SJeff Roberson int score; 155535e6168fSJeff Roberson int pri; 155635e6168fSJeff Roberson 1557c9a8cba4SJohn Baldwin if (PRI_BASE(td->td_pri_class) != PRI_TIMESHARE) 155815dc847eSJeff Roberson return; 1559e7d50326SJeff Roberson /* 1560e7d50326SJeff Roberson * If the score is interactive we place the thread in the realtime 1561e7d50326SJeff Roberson * queue with a priority that is less than kernel and interrupt 1562e7d50326SJeff Roberson * priorities. These threads are not subject to nice restrictions. 1563e7d50326SJeff Roberson * 1564ae7a6b38SJeff Roberson * Scores greater than this are placed on the normal timeshare queue 1565e7d50326SJeff Roberson * where the priority is partially decided by the most recent cpu 1566e7d50326SJeff Roberson * utilization and the rest is decided by nice value. 1567a5423ea3SJeff Roberson * 1568a5423ea3SJeff Roberson * The nice value of the process has a linear effect on the calculated 1569a5423ea3SJeff Roberson * score. Negative nice values make it easier for a thread to be 1570a5423ea3SJeff Roberson * considered interactive. 1571e7d50326SJeff Roberson */ 1572a0f15352SJohn Baldwin score = imax(0, sched_interact_score(td) + td->td_proc->p_nice); 1573e7d50326SJeff Roberson if (score < sched_interact) { 157412d56c0fSJohn Baldwin pri = PRI_MIN_INTERACT; 157512d56c0fSJohn Baldwin pri += ((PRI_MAX_INTERACT - PRI_MIN_INTERACT + 1) / 157678920008SJohn Baldwin sched_interact) * score; 157712d56c0fSJohn Baldwin KASSERT(pri >= PRI_MIN_INTERACT && pri <= PRI_MAX_INTERACT, 15789a93305aSJeff Roberson ("sched_priority: invalid interactive priority %d score %d", 15799a93305aSJeff Roberson pri, score)); 1580e7d50326SJeff Roberson } else { 1581e7d50326SJeff Roberson pri = SCHED_PRI_MIN; 158293ccd6bfSKonstantin Belousov if (td_get_sched(td)->ts_ticks) 158393ccd6bfSKonstantin Belousov pri += min(SCHED_PRI_TICKS(td_get_sched(td)), 15845457fa23SJohn Baldwin SCHED_PRI_RANGE - 1); 1585e7d50326SJeff Roberson pri += SCHED_PRI_NICE(td->td_proc->p_nice); 158612d56c0fSJohn Baldwin KASSERT(pri >= PRI_MIN_BATCH && pri <= PRI_MAX_BATCH, 1587ae7a6b38SJeff Roberson ("sched_priority: invalid priority %d: nice %d, " 1588ae7a6b38SJeff Roberson "ticks %d ftick %d ltick %d tick pri %d", 158993ccd6bfSKonstantin Belousov pri, td->td_proc->p_nice, td_get_sched(td)->ts_ticks, 159093ccd6bfSKonstantin Belousov td_get_sched(td)->ts_ftick, td_get_sched(td)->ts_ltick, 159193ccd6bfSKonstantin Belousov SCHED_PRI_TICKS(td_get_sched(td)))); 1592e7d50326SJeff Roberson } 15938460a577SJohn Birrell sched_user_prio(td, pri); 159435e6168fSJeff Roberson 159515dc847eSJeff Roberson return; 159635e6168fSJeff Roberson } 159735e6168fSJeff Roberson 159835e6168fSJeff Roberson /* 1599d322132cSJeff Roberson * This routine enforces a maximum limit on the amount of scheduling history 1600ae7a6b38SJeff Roberson * kept. It is called after either the slptime or runtime is adjusted. This 1601ae7a6b38SJeff Roberson * function is ugly due to integer math. 1602d322132cSJeff Roberson */ 16034b60e324SJeff Roberson static void 16048460a577SJohn Birrell sched_interact_update(struct thread *td) 16054b60e324SJeff Roberson { 1606155b6ca1SJeff Roberson struct td_sched *ts; 16079a93305aSJeff Roberson u_int sum; 16083f741ca1SJeff Roberson 160993ccd6bfSKonstantin Belousov ts = td_get_sched(td); 1610ae7a6b38SJeff Roberson sum = ts->ts_runtime + ts->ts_slptime; 1611d322132cSJeff Roberson if (sum < SCHED_SLP_RUN_MAX) 1612d322132cSJeff Roberson return; 1613d322132cSJeff Roberson /* 1614155b6ca1SJeff Roberson * This only happens from two places: 1615155b6ca1SJeff Roberson * 1) We have added an unusual amount of run time from fork_exit. 1616155b6ca1SJeff Roberson * 2) We have added an unusual amount of sleep time from sched_sleep(). 1617155b6ca1SJeff Roberson */ 1618155b6ca1SJeff Roberson if (sum > SCHED_SLP_RUN_MAX * 2) { 1619ae7a6b38SJeff Roberson if (ts->ts_runtime > ts->ts_slptime) { 1620ae7a6b38SJeff Roberson ts->ts_runtime = SCHED_SLP_RUN_MAX; 1621ae7a6b38SJeff Roberson ts->ts_slptime = 1; 1622155b6ca1SJeff Roberson } else { 1623ae7a6b38SJeff Roberson ts->ts_slptime = SCHED_SLP_RUN_MAX; 1624ae7a6b38SJeff Roberson ts->ts_runtime = 1; 1625155b6ca1SJeff Roberson } 1626155b6ca1SJeff Roberson return; 1627155b6ca1SJeff Roberson } 1628155b6ca1SJeff Roberson /* 1629d322132cSJeff Roberson * If we have exceeded by more than 1/5th then the algorithm below 1630d322132cSJeff Roberson * will not bring us back into range. Dividing by two here forces 16312454aaf5SJeff Roberson * us into the range of [4/5 * SCHED_INTERACT_MAX, SCHED_INTERACT_MAX] 1632d322132cSJeff Roberson */ 163337a35e4aSJeff Roberson if (sum > (SCHED_SLP_RUN_MAX / 5) * 6) { 1634ae7a6b38SJeff Roberson ts->ts_runtime /= 2; 1635ae7a6b38SJeff Roberson ts->ts_slptime /= 2; 1636d322132cSJeff Roberson return; 1637d322132cSJeff Roberson } 1638ae7a6b38SJeff Roberson ts->ts_runtime = (ts->ts_runtime / 5) * 4; 1639ae7a6b38SJeff Roberson ts->ts_slptime = (ts->ts_slptime / 5) * 4; 1640d322132cSJeff Roberson } 1641d322132cSJeff Roberson 1642ae7a6b38SJeff Roberson /* 1643ae7a6b38SJeff Roberson * Scale back the interactivity history when a child thread is created. The 1644ae7a6b38SJeff Roberson * history is inherited from the parent but the thread may behave totally 1645ae7a6b38SJeff Roberson * differently. For example, a shell spawning a compiler process. We want 1646ae7a6b38SJeff Roberson * to learn that the compiler is behaving badly very quickly. 1647ae7a6b38SJeff Roberson */ 1648d322132cSJeff Roberson static void 16498460a577SJohn Birrell sched_interact_fork(struct thread *td) 1650d322132cSJeff Roberson { 165193ccd6bfSKonstantin Belousov struct td_sched *ts; 1652d322132cSJeff Roberson int ratio; 1653d322132cSJeff Roberson int sum; 1654d322132cSJeff Roberson 165593ccd6bfSKonstantin Belousov ts = td_get_sched(td); 165693ccd6bfSKonstantin Belousov sum = ts->ts_runtime + ts->ts_slptime; 1657d322132cSJeff Roberson if (sum > SCHED_SLP_RUN_FORK) { 1658d322132cSJeff Roberson ratio = sum / SCHED_SLP_RUN_FORK; 165993ccd6bfSKonstantin Belousov ts->ts_runtime /= ratio; 166093ccd6bfSKonstantin Belousov ts->ts_slptime /= ratio; 16614b60e324SJeff Roberson } 16624b60e324SJeff Roberson } 16634b60e324SJeff Roberson 166415dc847eSJeff Roberson /* 1665ae7a6b38SJeff Roberson * Called from proc0_init() to setup the scheduler fields. 1666ed062c8dSJulian Elischer */ 1667ed062c8dSJulian Elischer void 1668ed062c8dSJulian Elischer schedinit(void) 1669ed062c8dSJulian Elischer { 167093ccd6bfSKonstantin Belousov struct td_sched *ts0; 1671e7d50326SJeff Roberson 1672ed062c8dSJulian Elischer /* 167393ccd6bfSKonstantin Belousov * Set up the scheduler specific parts of thread0. 1674ed062c8dSJulian Elischer */ 167593ccd6bfSKonstantin Belousov ts0 = td_get_sched(&thread0); 167693ccd6bfSKonstantin Belousov ts0->ts_ltick = ticks; 167793ccd6bfSKonstantin Belousov ts0->ts_ftick = ticks; 167893ccd6bfSKonstantin Belousov ts0->ts_slice = 0; 16791408b84aSHans Petter Selasky ts0->ts_cpu = curcpu; /* set valid CPU number */ 1680ed062c8dSJulian Elischer } 1681ed062c8dSJulian Elischer 1682ed062c8dSJulian Elischer /* 168315dc847eSJeff Roberson * This is only somewhat accurate since given many processes of the same 168415dc847eSJeff Roberson * priority they will switch when their slices run out, which will be 1685e7d50326SJeff Roberson * at most sched_slice stathz ticks. 168615dc847eSJeff Roberson */ 168735e6168fSJeff Roberson int 168835e6168fSJeff Roberson sched_rr_interval(void) 168935e6168fSJeff Roberson { 1690e7d50326SJeff Roberson 1691579895dfSAlexander Motin /* Convert sched_slice from stathz to hz. */ 169237f4e025SAlexander Motin return (imax(1, (sched_slice * hz + realstathz / 2) / realstathz)); 169335e6168fSJeff Roberson } 169435e6168fSJeff Roberson 1695ae7a6b38SJeff Roberson /* 1696ae7a6b38SJeff Roberson * Update the percent cpu tracking information when it is requested or 1697ae7a6b38SJeff Roberson * the total history exceeds the maximum. We keep a sliding history of 1698ae7a6b38SJeff Roberson * tick counts that slowly decays. This is less precise than the 4BSD 1699ae7a6b38SJeff Roberson * mechanism since it happens with less regular and frequent events. 1700ae7a6b38SJeff Roberson */ 170122bf7d9aSJeff Roberson static void 17027295465eSAlexander Motin sched_pctcpu_update(struct td_sched *ts, int run) 170335e6168fSJeff Roberson { 17047295465eSAlexander Motin int t = ticks; 1705e7d50326SJeff Roberson 170678133024SMark Johnston /* 170778133024SMark Johnston * The signed difference may be negative if the thread hasn't run for 170878133024SMark Johnston * over half of the ticks rollover period. 170978133024SMark Johnston */ 171078133024SMark Johnston if ((u_int)(t - ts->ts_ltick) >= SCHED_TICK_TARG) { 1711ad1e7d28SJulian Elischer ts->ts_ticks = 0; 17127295465eSAlexander Motin ts->ts_ftick = t - SCHED_TICK_TARG; 17137295465eSAlexander Motin } else if (t - ts->ts_ftick >= SCHED_TICK_MAX) { 17147295465eSAlexander Motin ts->ts_ticks = (ts->ts_ticks / (ts->ts_ltick - ts->ts_ftick)) * 17157295465eSAlexander Motin (ts->ts_ltick - (t - SCHED_TICK_TARG)); 17167295465eSAlexander Motin ts->ts_ftick = t - SCHED_TICK_TARG; 17177295465eSAlexander Motin } 17187295465eSAlexander Motin if (run) 17197295465eSAlexander Motin ts->ts_ticks += (t - ts->ts_ltick) << SCHED_TICK_SHIFT; 17207295465eSAlexander Motin ts->ts_ltick = t; 172135e6168fSJeff Roberson } 172235e6168fSJeff Roberson 1723ae7a6b38SJeff Roberson /* 1724ae7a6b38SJeff Roberson * Adjust the priority of a thread. Move it to the appropriate run-queue 1725ae7a6b38SJeff Roberson * if necessary. This is the back-end for several priority related 1726ae7a6b38SJeff Roberson * functions. 1727ae7a6b38SJeff Roberson */ 1728e7d50326SJeff Roberson static void 1729f5c157d9SJohn Baldwin sched_thread_priority(struct thread *td, u_char prio) 173035e6168fSJeff Roberson { 1731ad1e7d28SJulian Elischer struct td_sched *ts; 173273daf66fSJeff Roberson struct tdq *tdq; 173373daf66fSJeff Roberson int oldpri; 173435e6168fSJeff Roberson 17358f51ad55SJeff Roberson KTR_POINT3(KTR_SCHED, "thread", sched_tdname(td), "prio", 17368f51ad55SJeff Roberson "prio:%d", td->td_priority, "new prio:%d", prio, 17378f51ad55SJeff Roberson KTR_ATTR_LINKED, sched_tdname(curthread)); 1738d9fae5abSAndriy Gapon SDT_PROBE3(sched, , , change__pri, td, td->td_proc, prio); 1739e87fc7cfSAndriy Gapon if (td != curthread && prio < td->td_priority) { 17408f51ad55SJeff Roberson KTR_POINT3(KTR_SCHED, "thread", sched_tdname(curthread), 17418f51ad55SJeff Roberson "lend prio", "prio:%d", td->td_priority, "new prio:%d", 17428f51ad55SJeff Roberson prio, KTR_ATTR_LINKED, sched_tdname(td)); 1743d9fae5abSAndriy Gapon SDT_PROBE4(sched, , , lend__pri, td, td->td_proc, prio, 1744b3e9e682SRyan Stone curthread); 17458f51ad55SJeff Roberson } 174693ccd6bfSKonstantin Belousov ts = td_get_sched(td); 17477b20fb19SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 1748f5c157d9SJohn Baldwin if (td->td_priority == prio) 1749f5c157d9SJohn Baldwin return; 17503f741ca1SJeff Roberson /* 17513f741ca1SJeff Roberson * If the priority has been elevated due to priority 17523f741ca1SJeff Roberson * propagation, we may have to move ourselves to a new 1753e7d50326SJeff Roberson * queue. This could be optimized to not re-add in some 1754e7d50326SJeff Roberson * cases. 1755f2b74cbfSJeff Roberson */ 17566d55b3ecSJeff Roberson if (TD_ON_RUNQ(td) && prio < td->td_priority) { 1757e7d50326SJeff Roberson sched_rem(td); 1758e7d50326SJeff Roberson td->td_priority = prio; 175961a74c5cSJeff Roberson sched_add(td, SRQ_BORROWING | SRQ_HOLDTD); 176073daf66fSJeff Roberson return; 176173daf66fSJeff Roberson } 17626d55b3ecSJeff Roberson /* 17636d55b3ecSJeff Roberson * If the thread is currently running we may have to adjust the lowpri 17646d55b3ecSJeff Roberson * information so other cpus are aware of our current priority. 17656d55b3ecSJeff Roberson */ 17666d55b3ecSJeff Roberson if (TD_IS_RUNNING(td)) { 1767ae7a6b38SJeff Roberson tdq = TDQ_CPU(ts->ts_cpu); 176862fa74d9SJeff Roberson oldpri = td->td_priority; 17693f741ca1SJeff Roberson td->td_priority = prio; 177062fa74d9SJeff Roberson if (prio < tdq->tdq_lowpri) 177162fa74d9SJeff Roberson tdq->tdq_lowpri = prio; 177262fa74d9SJeff Roberson else if (tdq->tdq_lowpri == oldpri) 177362fa74d9SJeff Roberson tdq_setlowpri(tdq, td); 17746d55b3ecSJeff Roberson return; 177573daf66fSJeff Roberson } 17766d55b3ecSJeff Roberson td->td_priority = prio; 1777ae7a6b38SJeff Roberson } 177835e6168fSJeff Roberson 1779f5c157d9SJohn Baldwin /* 1780f5c157d9SJohn Baldwin * Update a thread's priority when it is lent another thread's 1781f5c157d9SJohn Baldwin * priority. 1782f5c157d9SJohn Baldwin */ 1783f5c157d9SJohn Baldwin void 1784f5c157d9SJohn Baldwin sched_lend_prio(struct thread *td, u_char prio) 1785f5c157d9SJohn Baldwin { 1786f5c157d9SJohn Baldwin 1787f5c157d9SJohn Baldwin td->td_flags |= TDF_BORROWING; 1788f5c157d9SJohn Baldwin sched_thread_priority(td, prio); 1789f5c157d9SJohn Baldwin } 1790f5c157d9SJohn Baldwin 1791f5c157d9SJohn Baldwin /* 1792f5c157d9SJohn Baldwin * Restore a thread's priority when priority propagation is 1793f5c157d9SJohn Baldwin * over. The prio argument is the minimum priority the thread 1794f5c157d9SJohn Baldwin * needs to have to satisfy other possible priority lending 1795f5c157d9SJohn Baldwin * requests. If the thread's regular priority is less 1796f5c157d9SJohn Baldwin * important than prio, the thread will keep a priority boost 1797f5c157d9SJohn Baldwin * of prio. 1798f5c157d9SJohn Baldwin */ 1799f5c157d9SJohn Baldwin void 1800f5c157d9SJohn Baldwin sched_unlend_prio(struct thread *td, u_char prio) 1801f5c157d9SJohn Baldwin { 1802f5c157d9SJohn Baldwin u_char base_pri; 1803f5c157d9SJohn Baldwin 1804f5c157d9SJohn Baldwin if (td->td_base_pri >= PRI_MIN_TIMESHARE && 1805f5c157d9SJohn Baldwin td->td_base_pri <= PRI_MAX_TIMESHARE) 18068460a577SJohn Birrell base_pri = td->td_user_pri; 1807f5c157d9SJohn Baldwin else 1808f5c157d9SJohn Baldwin base_pri = td->td_base_pri; 1809f5c157d9SJohn Baldwin if (prio >= base_pri) { 1810f5c157d9SJohn Baldwin td->td_flags &= ~TDF_BORROWING; 1811f5c157d9SJohn Baldwin sched_thread_priority(td, base_pri); 1812f5c157d9SJohn Baldwin } else 1813f5c157d9SJohn Baldwin sched_lend_prio(td, prio); 1814f5c157d9SJohn Baldwin } 1815f5c157d9SJohn Baldwin 1816ae7a6b38SJeff Roberson /* 1817ae7a6b38SJeff Roberson * Standard entry for setting the priority to an absolute value. 1818ae7a6b38SJeff Roberson */ 1819f5c157d9SJohn Baldwin void 1820f5c157d9SJohn Baldwin sched_prio(struct thread *td, u_char prio) 1821f5c157d9SJohn Baldwin { 1822f5c157d9SJohn Baldwin u_char oldprio; 1823f5c157d9SJohn Baldwin 1824f5c157d9SJohn Baldwin /* First, update the base priority. */ 1825f5c157d9SJohn Baldwin td->td_base_pri = prio; 1826f5c157d9SJohn Baldwin 1827f5c157d9SJohn Baldwin /* 182850aaa791SJohn Baldwin * If the thread is borrowing another thread's priority, don't 1829f5c157d9SJohn Baldwin * ever lower the priority. 1830f5c157d9SJohn Baldwin */ 1831f5c157d9SJohn Baldwin if (td->td_flags & TDF_BORROWING && td->td_priority < prio) 1832f5c157d9SJohn Baldwin return; 1833f5c157d9SJohn Baldwin 1834f5c157d9SJohn Baldwin /* Change the real priority. */ 1835f5c157d9SJohn Baldwin oldprio = td->td_priority; 1836f5c157d9SJohn Baldwin sched_thread_priority(td, prio); 1837f5c157d9SJohn Baldwin 1838f5c157d9SJohn Baldwin /* 1839f5c157d9SJohn Baldwin * If the thread is on a turnstile, then let the turnstile update 1840f5c157d9SJohn Baldwin * its state. 1841f5c157d9SJohn Baldwin */ 1842f5c157d9SJohn Baldwin if (TD_ON_LOCK(td) && oldprio != prio) 1843f5c157d9SJohn Baldwin turnstile_adjust(td, oldprio); 1844f5c157d9SJohn Baldwin } 1845f5c157d9SJohn Baldwin 1846ae7a6b38SJeff Roberson /* 1847ae7a6b38SJeff Roberson * Set the base user priority, does not effect current running priority. 1848ae7a6b38SJeff Roberson */ 184935e6168fSJeff Roberson void 18508460a577SJohn Birrell sched_user_prio(struct thread *td, u_char prio) 18513db720fdSDavid Xu { 18523db720fdSDavid Xu 18538460a577SJohn Birrell td->td_base_user_pri = prio; 1854acbe332aSDavid Xu if (td->td_lend_user_pri <= prio) 1855fc6c30f6SJulian Elischer return; 18568460a577SJohn Birrell td->td_user_pri = prio; 18573db720fdSDavid Xu } 18583db720fdSDavid Xu 18593db720fdSDavid Xu void 18603db720fdSDavid Xu sched_lend_user_prio(struct thread *td, u_char prio) 18613db720fdSDavid Xu { 18623db720fdSDavid Xu 1863435806d3SDavid Xu THREAD_LOCK_ASSERT(td, MA_OWNED); 1864acbe332aSDavid Xu td->td_lend_user_pri = prio; 1865c8e368a9SDavid Xu td->td_user_pri = min(prio, td->td_base_user_pri); 1866c8e368a9SDavid Xu if (td->td_priority > td->td_user_pri) 1867c8e368a9SDavid Xu sched_prio(td, td->td_user_pri); 1868c8e368a9SDavid Xu else if (td->td_priority != td->td_user_pri) 1869c8e368a9SDavid Xu td->td_flags |= TDF_NEEDRESCHED; 1870435806d3SDavid Xu } 18713db720fdSDavid Xu 1872ac97da9aSMateusz Guzik /* 1873ac97da9aSMateusz Guzik * Like the above but first check if there is anything to do. 1874ac97da9aSMateusz Guzik */ 1875ac97da9aSMateusz Guzik void 1876ac97da9aSMateusz Guzik sched_lend_user_prio_cond(struct thread *td, u_char prio) 1877ac97da9aSMateusz Guzik { 1878ac97da9aSMateusz Guzik 1879ac97da9aSMateusz Guzik if (td->td_lend_user_pri != prio) 1880ac97da9aSMateusz Guzik goto lend; 1881ac97da9aSMateusz Guzik if (td->td_user_pri != min(prio, td->td_base_user_pri)) 1882ac97da9aSMateusz Guzik goto lend; 1883b77594bbSMateusz Guzik if (td->td_priority != td->td_user_pri) 1884ac97da9aSMateusz Guzik goto lend; 1885ac97da9aSMateusz Guzik return; 1886ac97da9aSMateusz Guzik 1887ac97da9aSMateusz Guzik lend: 1888ac97da9aSMateusz Guzik thread_lock(td); 1889ac97da9aSMateusz Guzik sched_lend_user_prio(td, prio); 1890ac97da9aSMateusz Guzik thread_unlock(td); 1891ac97da9aSMateusz Guzik } 1892ac97da9aSMateusz Guzik 18934c8a8cfcSKonstantin Belousov #ifdef SMP 1894ae7a6b38SJeff Roberson /* 189597e9382dSDon Lewis * This tdq is about to idle. Try to steal a thread from another CPU before 189697e9382dSDon Lewis * choosing the idle thread. 189797e9382dSDon Lewis */ 189897e9382dSDon Lewis static void 189997e9382dSDon Lewis tdq_trysteal(struct tdq *tdq) 190097e9382dSDon Lewis { 19012668bb2aSAlexander Motin struct cpu_group *cg, *parent; 190297e9382dSDon Lewis struct tdq *steal; 190397e9382dSDon Lewis cpuset_t mask; 19042668bb2aSAlexander Motin int cpu, i, goup; 190597e9382dSDon Lewis 190697e9382dSDon Lewis if (smp_started == 0 || trysteal_limit == 0 || tdq->tdq_cg == NULL) 190797e9382dSDon Lewis return; 190897e9382dSDon Lewis CPU_FILL(&mask); 190997e9382dSDon Lewis CPU_CLR(PCPU_GET(cpuid), &mask); 191097e9382dSDon Lewis /* We don't want to be preempted while we're iterating. */ 191197e9382dSDon Lewis spinlock_enter(); 191297e9382dSDon Lewis TDQ_UNLOCK(tdq); 19132668bb2aSAlexander Motin for (i = 1, cg = tdq->tdq_cg, goup = 0; ; ) { 1914aefe0a8cSAlexander Motin cpu = sched_highest(cg, &mask, steal_thresh); 191597e9382dSDon Lewis /* 191697e9382dSDon Lewis * If a thread was added while interrupts were disabled don't 191797e9382dSDon Lewis * steal one here. 191897e9382dSDon Lewis */ 191997e9382dSDon Lewis if (tdq->tdq_load > 0) { 192097e9382dSDon Lewis TDQ_LOCK(tdq); 192197e9382dSDon Lewis break; 192297e9382dSDon Lewis } 19232668bb2aSAlexander Motin 19242668bb2aSAlexander Motin /* 19252668bb2aSAlexander Motin * We found no CPU to steal from in this group. Escalate to 19262668bb2aSAlexander Motin * the parent and repeat. But if parent has only two children 19272668bb2aSAlexander Motin * groups we can avoid searching this group again by searching 19282668bb2aSAlexander Motin * the other one specifically and then escalating two levels. 19292668bb2aSAlexander Motin */ 193097e9382dSDon Lewis if (cpu == -1) { 19312668bb2aSAlexander Motin if (goup) { 193297e9382dSDon Lewis cg = cg->cg_parent; 19332668bb2aSAlexander Motin goup = 0; 19342668bb2aSAlexander Motin } 19352668bb2aSAlexander Motin if (++i > trysteal_limit) { 193697e9382dSDon Lewis TDQ_LOCK(tdq); 193797e9382dSDon Lewis break; 193897e9382dSDon Lewis } 19392668bb2aSAlexander Motin parent = cg->cg_parent; 19402668bb2aSAlexander Motin if (parent == NULL) { 19412668bb2aSAlexander Motin TDQ_LOCK(tdq); 19422668bb2aSAlexander Motin break; 19432668bb2aSAlexander Motin } 19442668bb2aSAlexander Motin if (parent->cg_children == 2) { 19452668bb2aSAlexander Motin if (cg == &parent->cg_child[0]) 19462668bb2aSAlexander Motin cg = &parent->cg_child[1]; 19472668bb2aSAlexander Motin else 19482668bb2aSAlexander Motin cg = &parent->cg_child[0]; 19492668bb2aSAlexander Motin goup = 1; 19502668bb2aSAlexander Motin } else 19512668bb2aSAlexander Motin cg = parent; 195297e9382dSDon Lewis continue; 195397e9382dSDon Lewis } 195497e9382dSDon Lewis steal = TDQ_CPU(cpu); 195597e9382dSDon Lewis /* 195697e9382dSDon Lewis * The data returned by sched_highest() is stale and 195797e9382dSDon Lewis * the chosen CPU no longer has an eligible thread. 195897e9382dSDon Lewis */ 195997e9382dSDon Lewis if (steal->tdq_load < steal_thresh || 196097e9382dSDon Lewis steal->tdq_transferable == 0) 196197e9382dSDon Lewis continue; 196297e9382dSDon Lewis /* 1963*8bb173fbSAlexander Motin * Try to lock both queues. If we are assigned a thread while 1964*8bb173fbSAlexander Motin * waited for the lock, switch to it now instead of stealing. 1965*8bb173fbSAlexander Motin * If we can't get the lock, then somebody likely got there 1966*8bb173fbSAlexander Motin * first. At this point unconditonally exit the loop to 1967*8bb173fbSAlexander Motin * bound the time spent in the critcal section. 196897e9382dSDon Lewis */ 1969*8bb173fbSAlexander Motin TDQ_LOCK(tdq); 1970*8bb173fbSAlexander Motin if (tdq->tdq_load > 0) 197197e9382dSDon Lewis break; 1972*8bb173fbSAlexander Motin if (TDQ_TRYLOCK_FLAGS(steal, MTX_DUPOK) == 0) 1973*8bb173fbSAlexander Motin break; 197497e9382dSDon Lewis /* 197597e9382dSDon Lewis * The data returned by sched_highest() is stale and 197697e9382dSDon Lewis * the chosen CPU no longer has an eligible thread. 197797e9382dSDon Lewis */ 197897e9382dSDon Lewis if (steal->tdq_load < steal_thresh || 197997e9382dSDon Lewis steal->tdq_transferable == 0) { 198097e9382dSDon Lewis TDQ_UNLOCK(steal); 198197e9382dSDon Lewis break; 198297e9382dSDon Lewis } 198397e9382dSDon Lewis /* 198497e9382dSDon Lewis * If we fail to acquire one due to affinity restrictions, 198597e9382dSDon Lewis * bail out and let the idle thread to a more complete search 198697e9382dSDon Lewis * outside of a critical section. 198797e9382dSDon Lewis */ 198897e9382dSDon Lewis if (tdq_move(steal, tdq) == NULL) { 198997e9382dSDon Lewis TDQ_UNLOCK(steal); 199097e9382dSDon Lewis break; 199197e9382dSDon Lewis } 199297e9382dSDon Lewis TDQ_UNLOCK(steal); 199397e9382dSDon Lewis break; 199497e9382dSDon Lewis } 199597e9382dSDon Lewis spinlock_exit(); 199697e9382dSDon Lewis } 19974c8a8cfcSKonstantin Belousov #endif 199897e9382dSDon Lewis 199997e9382dSDon Lewis /* 2000c47f202bSJeff Roberson * Handle migration from sched_switch(). This happens only for 2001c47f202bSJeff Roberson * cpu binding. 2002c47f202bSJeff Roberson */ 2003c47f202bSJeff Roberson static struct mtx * 2004c47f202bSJeff Roberson sched_switch_migrate(struct tdq *tdq, struct thread *td, int flags) 2005c47f202bSJeff Roberson { 2006c47f202bSJeff Roberson struct tdq *tdn; 2007c47f202bSJeff Roberson 2008686bcb5cSJeff Roberson KASSERT(THREAD_CAN_MIGRATE(td) || 2009686bcb5cSJeff Roberson (td_get_sched(td)->ts_flags & TSF_BOUND) != 0, 2010686bcb5cSJeff Roberson ("Thread %p shouldn't migrate", td)); 2011efe67753SNathan Whitehorn KASSERT(!CPU_ABSENT(td_get_sched(td)->ts_cpu), ("sched_switch_migrate: " 2012efe67753SNathan Whitehorn "thread %s queued on absent CPU %d.", td->td_name, 2013efe67753SNathan Whitehorn td_get_sched(td)->ts_cpu)); 201493ccd6bfSKonstantin Belousov tdn = TDQ_CPU(td_get_sched(td)->ts_cpu); 2015c47f202bSJeff Roberson #ifdef SMP 20169727e637SJeff Roberson tdq_load_rem(tdq, td); 2017c47f202bSJeff Roberson /* 2018686bcb5cSJeff Roberson * Do the lock dance required to avoid LOR. We have an 2019686bcb5cSJeff Roberson * extra spinlock nesting from sched_switch() which will 2020686bcb5cSJeff Roberson * prevent preemption while we're holding neither run-queue lock. 2021c47f202bSJeff Roberson */ 2022686bcb5cSJeff Roberson TDQ_UNLOCK(tdq); 2023686bcb5cSJeff Roberson TDQ_LOCK(tdn); 2024c47f202bSJeff Roberson tdq_add(tdn, td, flags); 202527ee18adSRyan Stone tdq_notify(tdn, td); 2026c47f202bSJeff Roberson TDQ_UNLOCK(tdn); 2027686bcb5cSJeff Roberson TDQ_LOCK(tdq); 2028c47f202bSJeff Roberson #endif 2029c47f202bSJeff Roberson return (TDQ_LOCKPTR(tdn)); 2030c47f202bSJeff Roberson } 2031c47f202bSJeff Roberson 2032c47f202bSJeff Roberson /* 203361a74c5cSJeff Roberson * thread_lock_unblock() that does not assume td_lock is blocked. 2034ae7a6b38SJeff Roberson */ 2035ae7a6b38SJeff Roberson static inline void 2036ae7a6b38SJeff Roberson thread_unblock_switch(struct thread *td, struct mtx *mtx) 2037ae7a6b38SJeff Roberson { 2038ae7a6b38SJeff Roberson atomic_store_rel_ptr((volatile uintptr_t *)&td->td_lock, 2039ae7a6b38SJeff Roberson (uintptr_t)mtx); 2040ae7a6b38SJeff Roberson } 2041ae7a6b38SJeff Roberson 2042ae7a6b38SJeff Roberson /* 2043ae7a6b38SJeff Roberson * Switch threads. This function has to handle threads coming in while 2044ae7a6b38SJeff Roberson * blocked for some reason, running, or idle. It also must deal with 2045ae7a6b38SJeff Roberson * migrating a thread from one queue to another as running threads may 2046ae7a6b38SJeff Roberson * be assigned elsewhere via binding. 2047ae7a6b38SJeff Roberson */ 20483db720fdSDavid Xu void 2049686bcb5cSJeff Roberson sched_switch(struct thread *td, int flags) 205035e6168fSJeff Roberson { 2051686bcb5cSJeff Roberson struct thread *newtd; 2052c02bbb43SJeff Roberson struct tdq *tdq; 2053ad1e7d28SJulian Elischer struct td_sched *ts; 2054ae7a6b38SJeff Roberson struct mtx *mtx; 2055c47f202bSJeff Roberson int srqflag; 20563d7f4117SAlexander Motin int cpuid, preempted; 205735e6168fSJeff Roberson 20587b20fb19SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 205935e6168fSJeff Roberson 2060ae7a6b38SJeff Roberson cpuid = PCPU_GET(cpuid); 2061018ff686SJeff Roberson tdq = TDQ_SELF(); 206293ccd6bfSKonstantin Belousov ts = td_get_sched(td); 20637295465eSAlexander Motin sched_pctcpu_update(ts, 1); 2064ae7a6b38SJeff Roberson ts->ts_rltick = ticks; 2065060563ecSJulian Elischer td->td_lastcpu = td->td_oncpu; 2066ad9dadc4SAndriy Gapon preempted = (td->td_flags & TDF_SLICEEND) == 0 && 2067ad9dadc4SAndriy Gapon (flags & SW_PREEMPT) != 0; 20683d7f4117SAlexander Motin td->td_flags &= ~(TDF_NEEDRESCHED | TDF_SLICEEND); 206977918643SStephan Uphoff td->td_owepreempt = 0; 20707789ab32SMark Johnston tdq->tdq_owepreempt = 0; 20712c27cb3aSAlexander Motin if (!TD_IS_IDLETHREAD(td)) 20721690c6c1SJeff Roberson tdq->tdq_switchcnt++; 20737789ab32SMark Johnston 2074b11fdad0SJeff Roberson /* 2075686bcb5cSJeff Roberson * Always block the thread lock so we can drop the tdq lock early. 2076b11fdad0SJeff Roberson */ 2077686bcb5cSJeff Roberson mtx = thread_lock_block(td); 2078686bcb5cSJeff Roberson spinlock_enter(); 2079486a9414SJulian Elischer if (TD_IS_IDLETHREAD(td)) { 2080686bcb5cSJeff Roberson MPASS(mtx == TDQ_LOCKPTR(tdq)); 2081bf0acc27SJohn Baldwin TD_SET_CAN_RUN(td); 20827b20fb19SJeff Roberson } else if (TD_IS_RUNNING(td)) { 2083686bcb5cSJeff Roberson MPASS(mtx == TDQ_LOCKPTR(tdq)); 20843d7f4117SAlexander Motin srqflag = preempted ? 2085598b368dSJeff Roberson SRQ_OURSELF|SRQ_YIELDING|SRQ_PREEMPTED : 2086c47f202bSJeff Roberson SRQ_OURSELF|SRQ_YIELDING; 2087ba4932b5SMatthew D Fleming #ifdef SMP 20880f7a0ebdSMatthew D Fleming if (THREAD_CAN_MIGRATE(td) && !THREAD_CAN_SCHED(td, ts->ts_cpu)) 20890f7a0ebdSMatthew D Fleming ts->ts_cpu = sched_pickcpu(td, 0); 2090ba4932b5SMatthew D Fleming #endif 2091c47f202bSJeff Roberson if (ts->ts_cpu == cpuid) 20929727e637SJeff Roberson tdq_runq_add(tdq, td, srqflag); 2093686bcb5cSJeff Roberson else 2094c47f202bSJeff Roberson mtx = sched_switch_migrate(tdq, td, srqflag); 2095ae7a6b38SJeff Roberson } else { 2096ae7a6b38SJeff Roberson /* This thread must be going to sleep. */ 209761a74c5cSJeff Roberson if (mtx != TDQ_LOCKPTR(tdq)) { 209861a74c5cSJeff Roberson mtx_unlock_spin(mtx); 209961a74c5cSJeff Roberson TDQ_LOCK(tdq); 210061a74c5cSJeff Roberson } 21019727e637SJeff Roberson tdq_load_rem(tdq, td); 21024c8a8cfcSKonstantin Belousov #ifdef SMP 210397e9382dSDon Lewis if (tdq->tdq_load == 0) 210497e9382dSDon Lewis tdq_trysteal(tdq); 21054c8a8cfcSKonstantin Belousov #endif 2106ae7a6b38SJeff Roberson } 2107afa0a46cSAndriy Gapon 2108afa0a46cSAndriy Gapon #if (KTR_COMPILE & KTR_SCHED) != 0 2109afa0a46cSAndriy Gapon if (TD_IS_IDLETHREAD(td)) 2110afa0a46cSAndriy Gapon KTR_STATE1(KTR_SCHED, "thread", sched_tdname(td), "idle", 2111afa0a46cSAndriy Gapon "prio:%d", td->td_priority); 2112afa0a46cSAndriy Gapon else 2113afa0a46cSAndriy Gapon KTR_STATE3(KTR_SCHED, "thread", sched_tdname(td), KTDSTATE(td), 2114afa0a46cSAndriy Gapon "prio:%d", td->td_priority, "wmesg:\"%s\"", td->td_wmesg, 2115afa0a46cSAndriy Gapon "lockname:\"%s\"", td->td_lockname); 2116afa0a46cSAndriy Gapon #endif 2117afa0a46cSAndriy Gapon 2118ae7a6b38SJeff Roberson /* 2119ae7a6b38SJeff Roberson * We enter here with the thread blocked and assigned to the 2120ae7a6b38SJeff Roberson * appropriate cpu run-queue or sleep-queue and with the current 2121ae7a6b38SJeff Roberson * thread-queue locked. 2122ae7a6b38SJeff Roberson */ 2123ae7a6b38SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED | MA_NOTRECURSED); 21242454aaf5SJeff Roberson newtd = choosethread(); 2125686bcb5cSJeff Roberson sched_pctcpu_update(td_get_sched(newtd), 0); 2126686bcb5cSJeff Roberson TDQ_UNLOCK(tdq); 2127686bcb5cSJeff Roberson 2128ae7a6b38SJeff Roberson /* 2129ae7a6b38SJeff Roberson * Call the MD code to switch contexts if necessary. 2130ae7a6b38SJeff Roberson */ 2131ebccf1e3SJoseph Koshy if (td != newtd) { 2132ebccf1e3SJoseph Koshy #ifdef HWPMC_HOOKS 2133ebccf1e3SJoseph Koshy if (PMC_PROC_IS_USING_PMCS(td->td_proc)) 2134ebccf1e3SJoseph Koshy PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_OUT); 2135ebccf1e3SJoseph Koshy #endif 2136d9fae5abSAndriy Gapon SDT_PROBE2(sched, , , off__cpu, newtd, newtd->td_proc); 21376f5f25e5SJohn Birrell 21386f5f25e5SJohn Birrell #ifdef KDTRACE_HOOKS 21396f5f25e5SJohn Birrell /* 21406f5f25e5SJohn Birrell * If DTrace has set the active vtime enum to anything 21416f5f25e5SJohn Birrell * other than INACTIVE (0), then it should have set the 21426f5f25e5SJohn Birrell * function to call. 21436f5f25e5SJohn Birrell */ 21446f5f25e5SJohn Birrell if (dtrace_vtime_active) 21456f5f25e5SJohn Birrell (*dtrace_vtime_switch_func)(newtd); 21466f5f25e5SJohn Birrell #endif 2147686bcb5cSJeff Roberson td->td_oncpu = NOCPU; 2148ae7a6b38SJeff Roberson cpu_switch(td, newtd, mtx); 2149a89c2c8cSMark Johnston cpuid = td->td_oncpu = PCPU_GET(cpuid); 2150b3e9e682SRyan Stone 2151d9fae5abSAndriy Gapon SDT_PROBE0(sched, , , on__cpu); 2152ebccf1e3SJoseph Koshy #ifdef HWPMC_HOOKS 2153ebccf1e3SJoseph Koshy if (PMC_PROC_IS_USING_PMCS(td->td_proc)) 2154ebccf1e3SJoseph Koshy PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_IN); 2155ebccf1e3SJoseph Koshy #endif 2156b3e9e682SRyan Stone } else { 2157ae7a6b38SJeff Roberson thread_unblock_switch(td, mtx); 2158d9fae5abSAndriy Gapon SDT_PROBE0(sched, , , remain__cpu); 2159b3e9e682SRyan Stone } 2160686bcb5cSJeff Roberson KASSERT(curthread->td_md.md_spinlock_count == 1, 2161686bcb5cSJeff Roberson ("invalid count %d", curthread->td_md.md_spinlock_count)); 2162afa0a46cSAndriy Gapon 2163afa0a46cSAndriy Gapon KTR_STATE1(KTR_SCHED, "thread", sched_tdname(td), "running", 2164afa0a46cSAndriy Gapon "prio:%d", td->td_priority); 216535e6168fSJeff Roberson } 216635e6168fSJeff Roberson 2167ae7a6b38SJeff Roberson /* 2168ae7a6b38SJeff Roberson * Adjust thread priorities as a result of a nice request. 2169ae7a6b38SJeff Roberson */ 217035e6168fSJeff Roberson void 2171fa885116SJulian Elischer sched_nice(struct proc *p, int nice) 217235e6168fSJeff Roberson { 217335e6168fSJeff Roberson struct thread *td; 217435e6168fSJeff Roberson 2175fa885116SJulian Elischer PROC_LOCK_ASSERT(p, MA_OWNED); 2176e7d50326SJeff Roberson 2177fa885116SJulian Elischer p->p_nice = nice; 21788460a577SJohn Birrell FOREACH_THREAD_IN_PROC(p, td) { 21797b20fb19SJeff Roberson thread_lock(td); 21808460a577SJohn Birrell sched_priority(td); 2181e7d50326SJeff Roberson sched_prio(td, td->td_base_user_pri); 21827b20fb19SJeff Roberson thread_unlock(td); 218335e6168fSJeff Roberson } 2184fa885116SJulian Elischer } 218535e6168fSJeff Roberson 2186ae7a6b38SJeff Roberson /* 2187ae7a6b38SJeff Roberson * Record the sleep time for the interactivity scorer. 2188ae7a6b38SJeff Roberson */ 218935e6168fSJeff Roberson void 2190c5aa6b58SJeff Roberson sched_sleep(struct thread *td, int prio) 219135e6168fSJeff Roberson { 2192e7d50326SJeff Roberson 21937b20fb19SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 219435e6168fSJeff Roberson 219554b0e65fSJeff Roberson td->td_slptick = ticks; 219617c4c356SKonstantin Belousov if (TD_IS_SUSPENDED(td) || prio >= PSOCK) 2197c5aa6b58SJeff Roberson td->td_flags |= TDF_CANSWAP; 21982dc29adbSJohn Baldwin if (PRI_BASE(td->td_pri_class) != PRI_TIMESHARE) 21992dc29adbSJohn Baldwin return; 22000502fe2eSJeff Roberson if (static_boost == 1 && prio) 2201c5aa6b58SJeff Roberson sched_prio(td, prio); 22020502fe2eSJeff Roberson else if (static_boost && td->td_priority > static_boost) 22030502fe2eSJeff Roberson sched_prio(td, static_boost); 220435e6168fSJeff Roberson } 220535e6168fSJeff Roberson 2206ae7a6b38SJeff Roberson /* 2207ae7a6b38SJeff Roberson * Schedule a thread to resume execution and record how long it voluntarily 2208ae7a6b38SJeff Roberson * slept. We also update the pctcpu, interactivity, and priority. 220961a74c5cSJeff Roberson * 221061a74c5cSJeff Roberson * Requires the thread lock on entry, drops on exit. 2211ae7a6b38SJeff Roberson */ 221235e6168fSJeff Roberson void 221361a74c5cSJeff Roberson sched_wakeup(struct thread *td, int srqflags) 221435e6168fSJeff Roberson { 221514618990SJeff Roberson struct td_sched *ts; 2216ae7a6b38SJeff Roberson int slptick; 2217e7d50326SJeff Roberson 22187b20fb19SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 221993ccd6bfSKonstantin Belousov ts = td_get_sched(td); 2220c5aa6b58SJeff Roberson td->td_flags &= ~TDF_CANSWAP; 222161a74c5cSJeff Roberson 222235e6168fSJeff Roberson /* 2223e7d50326SJeff Roberson * If we slept for more than a tick update our interactivity and 2224e7d50326SJeff Roberson * priority. 222535e6168fSJeff Roberson */ 222654b0e65fSJeff Roberson slptick = td->td_slptick; 222754b0e65fSJeff Roberson td->td_slptick = 0; 2228ae7a6b38SJeff Roberson if (slptick && slptick != ticks) { 22297295465eSAlexander Motin ts->ts_slptime += (ticks - slptick) << SCHED_TICK_SHIFT; 22308460a577SJohn Birrell sched_interact_update(td); 22317295465eSAlexander Motin sched_pctcpu_update(ts, 0); 2232f1e8dc4aSJeff Roberson } 22335e5c3873SJeff Roberson /* 22345e5c3873SJeff Roberson * Reset the slice value since we slept and advanced the round-robin. 22355e5c3873SJeff Roberson */ 22365e5c3873SJeff Roberson ts->ts_slice = 0; 223761a74c5cSJeff Roberson sched_add(td, SRQ_BORING | srqflags); 223835e6168fSJeff Roberson } 223935e6168fSJeff Roberson 224035e6168fSJeff Roberson /* 224135e6168fSJeff Roberson * Penalize the parent for creating a new child and initialize the child's 224235e6168fSJeff Roberson * priority. 224335e6168fSJeff Roberson */ 224435e6168fSJeff Roberson void 22458460a577SJohn Birrell sched_fork(struct thread *td, struct thread *child) 224615dc847eSJeff Roberson { 22477b20fb19SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 224893ccd6bfSKonstantin Belousov sched_pctcpu_update(td_get_sched(td), 1); 2249ad1e7d28SJulian Elischer sched_fork_thread(td, child); 2250e7d50326SJeff Roberson /* 2251e7d50326SJeff Roberson * Penalize the parent and child for forking. 2252e7d50326SJeff Roberson */ 2253e7d50326SJeff Roberson sched_interact_fork(child); 2254e7d50326SJeff Roberson sched_priority(child); 225593ccd6bfSKonstantin Belousov td_get_sched(td)->ts_runtime += tickincr; 2256e7d50326SJeff Roberson sched_interact_update(td); 2257e7d50326SJeff Roberson sched_priority(td); 2258ad1e7d28SJulian Elischer } 2259ad1e7d28SJulian Elischer 2260ae7a6b38SJeff Roberson /* 2261ae7a6b38SJeff Roberson * Fork a new thread, may be within the same process. 2262ae7a6b38SJeff Roberson */ 2263ad1e7d28SJulian Elischer void 2264ad1e7d28SJulian Elischer sched_fork_thread(struct thread *td, struct thread *child) 2265ad1e7d28SJulian Elischer { 2266ad1e7d28SJulian Elischer struct td_sched *ts; 2267ad1e7d28SJulian Elischer struct td_sched *ts2; 22685e5c3873SJeff Roberson struct tdq *tdq; 22698460a577SJohn Birrell 22705e5c3873SJeff Roberson tdq = TDQ_SELF(); 22718b16c208SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 2272e7d50326SJeff Roberson /* 2273e7d50326SJeff Roberson * Initialize child. 2274e7d50326SJeff Roberson */ 227593ccd6bfSKonstantin Belousov ts = td_get_sched(td); 227693ccd6bfSKonstantin Belousov ts2 = td_get_sched(child); 227792de34dfSJohn Baldwin child->td_oncpu = NOCPU; 227892de34dfSJohn Baldwin child->td_lastcpu = NOCPU; 22795e5c3873SJeff Roberson child->td_lock = TDQ_LOCKPTR(tdq); 22808b16c208SJeff Roberson child->td_cpuset = cpuset_ref(td->td_cpuset); 22813f289c3fSJeff Roberson child->td_domain.dr_policy = td->td_cpuset->cs_domain; 2282ad1e7d28SJulian Elischer ts2->ts_cpu = ts->ts_cpu; 22838b16c208SJeff Roberson ts2->ts_flags = 0; 2284e7d50326SJeff Roberson /* 228522d19207SJohn Baldwin * Grab our parents cpu estimation information. 2286e7d50326SJeff Roberson */ 2287ad1e7d28SJulian Elischer ts2->ts_ticks = ts->ts_ticks; 2288ad1e7d28SJulian Elischer ts2->ts_ltick = ts->ts_ltick; 2289ad1e7d28SJulian Elischer ts2->ts_ftick = ts->ts_ftick; 229022d19207SJohn Baldwin /* 229122d19207SJohn Baldwin * Do not inherit any borrowed priority from the parent. 229222d19207SJohn Baldwin */ 229322d19207SJohn Baldwin child->td_priority = child->td_base_pri; 2294e7d50326SJeff Roberson /* 2295e7d50326SJeff Roberson * And update interactivity score. 2296e7d50326SJeff Roberson */ 2297ae7a6b38SJeff Roberson ts2->ts_slptime = ts->ts_slptime; 2298ae7a6b38SJeff Roberson ts2->ts_runtime = ts->ts_runtime; 22995e5c3873SJeff Roberson /* Attempt to quickly learn interactivity. */ 23005e5c3873SJeff Roberson ts2->ts_slice = tdq_slice(tdq) - sched_slice_min; 23018f51ad55SJeff Roberson #ifdef KTR 23028f51ad55SJeff Roberson bzero(ts2->ts_name, sizeof(ts2->ts_name)); 23038f51ad55SJeff Roberson #endif 230415dc847eSJeff Roberson } 230515dc847eSJeff Roberson 2306ae7a6b38SJeff Roberson /* 2307ae7a6b38SJeff Roberson * Adjust the priority class of a thread. 2308ae7a6b38SJeff Roberson */ 230915dc847eSJeff Roberson void 23108460a577SJohn Birrell sched_class(struct thread *td, int class) 231115dc847eSJeff Roberson { 231215dc847eSJeff Roberson 23137b20fb19SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 23148460a577SJohn Birrell if (td->td_pri_class == class) 231515dc847eSJeff Roberson return; 23168460a577SJohn Birrell td->td_pri_class = class; 231735e6168fSJeff Roberson } 231835e6168fSJeff Roberson 231935e6168fSJeff Roberson /* 232035e6168fSJeff Roberson * Return some of the child's priority and interactivity to the parent. 232135e6168fSJeff Roberson */ 232235e6168fSJeff Roberson void 2323fc6c30f6SJulian Elischer sched_exit(struct proc *p, struct thread *child) 232435e6168fSJeff Roberson { 2325e7d50326SJeff Roberson struct thread *td; 2326141ad61cSJeff Roberson 23278f51ad55SJeff Roberson KTR_STATE1(KTR_SCHED, "thread", sched_tdname(child), "proc exit", 2328cd39bb09SXin LI "prio:%d", child->td_priority); 2329374ae2a3SJeff Roberson PROC_LOCK_ASSERT(p, MA_OWNED); 2330e7d50326SJeff Roberson td = FIRST_THREAD_IN_PROC(p); 2331e7d50326SJeff Roberson sched_exit_thread(td, child); 2332ad1e7d28SJulian Elischer } 2333ad1e7d28SJulian Elischer 2334ae7a6b38SJeff Roberson /* 2335ae7a6b38SJeff Roberson * Penalize another thread for the time spent on this one. This helps to 2336ae7a6b38SJeff Roberson * worsen the priority and interactivity of processes which schedule batch 2337ae7a6b38SJeff Roberson * jobs such as make. This has little effect on the make process itself but 2338ae7a6b38SJeff Roberson * causes new processes spawned by it to receive worse scores immediately. 2339ae7a6b38SJeff Roberson */ 2340ad1e7d28SJulian Elischer void 2341fc6c30f6SJulian Elischer sched_exit_thread(struct thread *td, struct thread *child) 2342ad1e7d28SJulian Elischer { 2343fc6c30f6SJulian Elischer 23448f51ad55SJeff Roberson KTR_STATE1(KTR_SCHED, "thread", sched_tdname(child), "thread exit", 2345cd39bb09SXin LI "prio:%d", child->td_priority); 2346e7d50326SJeff Roberson /* 2347e7d50326SJeff Roberson * Give the child's runtime to the parent without returning the 2348e7d50326SJeff Roberson * sleep time as a penalty to the parent. This causes shells that 2349e7d50326SJeff Roberson * launch expensive things to mark their children as expensive. 2350e7d50326SJeff Roberson */ 23517b20fb19SJeff Roberson thread_lock(td); 235293ccd6bfSKonstantin Belousov td_get_sched(td)->ts_runtime += td_get_sched(child)->ts_runtime; 2353fc6c30f6SJulian Elischer sched_interact_update(td); 2354e7d50326SJeff Roberson sched_priority(td); 23557b20fb19SJeff Roberson thread_unlock(td); 2356ad1e7d28SJulian Elischer } 2357ad1e7d28SJulian Elischer 2358ff256d9cSJeff Roberson void 2359ff256d9cSJeff Roberson sched_preempt(struct thread *td) 2360ff256d9cSJeff Roberson { 2361ff256d9cSJeff Roberson struct tdq *tdq; 2362686bcb5cSJeff Roberson int flags; 2363ff256d9cSJeff Roberson 2364b3e9e682SRyan Stone SDT_PROBE2(sched, , , surrender, td, td->td_proc); 2365b3e9e682SRyan Stone 2366ff256d9cSJeff Roberson thread_lock(td); 2367ff256d9cSJeff Roberson tdq = TDQ_SELF(); 2368ff256d9cSJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED); 2369ff256d9cSJeff Roberson if (td->td_priority > tdq->tdq_lowpri) { 2370686bcb5cSJeff Roberson if (td->td_critnest == 1) { 23718df78c41SJeff Roberson flags = SW_INVOL | SW_PREEMPT; 2372686bcb5cSJeff Roberson flags |= TD_IS_IDLETHREAD(td) ? SWT_REMOTEWAKEIDLE : 2373686bcb5cSJeff Roberson SWT_REMOTEPREEMPT; 2374686bcb5cSJeff Roberson mi_switch(flags); 2375686bcb5cSJeff Roberson /* Switch dropped thread lock. */ 2376686bcb5cSJeff Roberson return; 2377686bcb5cSJeff Roberson } 2378ff256d9cSJeff Roberson td->td_owepreempt = 1; 23797789ab32SMark Johnston } else { 23807789ab32SMark Johnston tdq->tdq_owepreempt = 0; 2381ff256d9cSJeff Roberson } 2382ff256d9cSJeff Roberson thread_unlock(td); 2383ff256d9cSJeff Roberson } 2384ff256d9cSJeff Roberson 2385ae7a6b38SJeff Roberson /* 2386ae7a6b38SJeff Roberson * Fix priorities on return to user-space. Priorities may be elevated due 2387ae7a6b38SJeff Roberson * to static priorities in msleep() or similar. 2388ae7a6b38SJeff Roberson */ 2389ad1e7d28SJulian Elischer void 239028240885SMateusz Guzik sched_userret_slowpath(struct thread *td) 2391ad1e7d28SJulian Elischer { 239228240885SMateusz Guzik 23937b20fb19SJeff Roberson thread_lock(td); 2394ad1e7d28SJulian Elischer td->td_priority = td->td_user_pri; 2395ad1e7d28SJulian Elischer td->td_base_pri = td->td_user_pri; 239662fa74d9SJeff Roberson tdq_setlowpri(TDQ_SELF(), td); 23977b20fb19SJeff Roberson thread_unlock(td); 2398ad1e7d28SJulian Elischer } 239935e6168fSJeff Roberson 2400ae7a6b38SJeff Roberson /* 2401ae7a6b38SJeff Roberson * Handle a stathz tick. This is really only relevant for timeshare 2402ae7a6b38SJeff Roberson * threads. 2403ae7a6b38SJeff Roberson */ 240435e6168fSJeff Roberson void 2405c3cccf95SJeff Roberson sched_clock(struct thread *td, int cnt) 240635e6168fSJeff Roberson { 2407ad1e7d28SJulian Elischer struct tdq *tdq; 2408ad1e7d28SJulian Elischer struct td_sched *ts; 240935e6168fSJeff Roberson 2410ae7a6b38SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 24113f872f85SJeff Roberson tdq = TDQ_SELF(); 24127fcf154aSJeff Roberson #ifdef SMP 24137fcf154aSJeff Roberson /* 24147fcf154aSJeff Roberson * We run the long term load balancer infrequently on the first cpu. 24157fcf154aSJeff Roberson */ 2416c3cccf95SJeff Roberson if (balance_tdq == tdq && smp_started != 0 && rebalance != 0 && 2417c3cccf95SJeff Roberson balance_ticks != 0) { 2418c3cccf95SJeff Roberson balance_ticks -= cnt; 2419c3cccf95SJeff Roberson if (balance_ticks <= 0) 24207fcf154aSJeff Roberson sched_balance(); 24217fcf154aSJeff Roberson } 24227fcf154aSJeff Roberson #endif 24233f872f85SJeff Roberson /* 24241690c6c1SJeff Roberson * Save the old switch count so we have a record of the last ticks 24251690c6c1SJeff Roberson * activity. Initialize the new switch count based on our load. 24261690c6c1SJeff Roberson * If there is some activity seed it to reflect that. 24271690c6c1SJeff Roberson */ 24281690c6c1SJeff Roberson tdq->tdq_oldswitchcnt = tdq->tdq_switchcnt; 24296c47aaaeSJeff Roberson tdq->tdq_switchcnt = tdq->tdq_load; 24301690c6c1SJeff Roberson /* 24313f872f85SJeff Roberson * Advance the insert index once for each tick to ensure that all 24323f872f85SJeff Roberson * threads get a chance to run. 24333f872f85SJeff Roberson */ 24343f872f85SJeff Roberson if (tdq->tdq_idx == tdq->tdq_ridx) { 24353f872f85SJeff Roberson tdq->tdq_idx = (tdq->tdq_idx + 1) % RQ_NQS; 24363f872f85SJeff Roberson if (TAILQ_EMPTY(&tdq->tdq_timeshare.rq_queues[tdq->tdq_ridx])) 24373f872f85SJeff Roberson tdq->tdq_ridx = tdq->tdq_idx; 24383f872f85SJeff Roberson } 243993ccd6bfSKonstantin Belousov ts = td_get_sched(td); 24407295465eSAlexander Motin sched_pctcpu_update(ts, 1); 2441c3cccf95SJeff Roberson if ((td->td_pri_class & PRI_FIFO_BIT) || TD_IS_IDLETHREAD(td)) 2442a8949de2SJeff Roberson return; 2443c3cccf95SJeff Roberson 2444c9a8cba4SJohn Baldwin if (PRI_BASE(td->td_pri_class) == PRI_TIMESHARE) { 2445a8949de2SJeff Roberson /* 2446fd0b8c78SJeff Roberson * We used a tick; charge it to the thread so 2447fd0b8c78SJeff Roberson * that we can compute our interactivity. 244815dc847eSJeff Roberson */ 2449c3cccf95SJeff Roberson td_get_sched(td)->ts_runtime += tickincr * cnt; 24508460a577SJohn Birrell sched_interact_update(td); 245173daf66fSJeff Roberson sched_priority(td); 2452fd0b8c78SJeff Roberson } 2453579895dfSAlexander Motin 245435e6168fSJeff Roberson /* 2455579895dfSAlexander Motin * Force a context switch if the current thread has used up a full 2456579895dfSAlexander Motin * time slice (default is 100ms). 245735e6168fSJeff Roberson */ 2458c3cccf95SJeff Roberson ts->ts_slice += cnt; 2459c3cccf95SJeff Roberson if (ts->ts_slice >= tdq_slice(tdq)) { 24605e5c3873SJeff Roberson ts->ts_slice = 0; 24613d7f4117SAlexander Motin td->td_flags |= TDF_NEEDRESCHED | TDF_SLICEEND; 246235e6168fSJeff Roberson } 2463579895dfSAlexander Motin } 246435e6168fSJeff Roberson 2465ccd0ec40SKonstantin Belousov u_int 2466ccd0ec40SKonstantin Belousov sched_estcpu(struct thread *td __unused) 2467ae7a6b38SJeff Roberson { 2468ae7a6b38SJeff Roberson 2469ccd0ec40SKonstantin Belousov return (0); 2470ae7a6b38SJeff Roberson } 2471ae7a6b38SJeff Roberson 2472ae7a6b38SJeff Roberson /* 2473ae7a6b38SJeff Roberson * Return whether the current CPU has runnable tasks. Used for in-kernel 2474ae7a6b38SJeff Roberson * cooperative idle threads. 2475ae7a6b38SJeff Roberson */ 247635e6168fSJeff Roberson int 247735e6168fSJeff Roberson sched_runnable(void) 247835e6168fSJeff Roberson { 2479ad1e7d28SJulian Elischer struct tdq *tdq; 2480b90816f1SJeff Roberson int load; 248135e6168fSJeff Roberson 2482b90816f1SJeff Roberson load = 1; 2483b90816f1SJeff Roberson 2484ad1e7d28SJulian Elischer tdq = TDQ_SELF(); 24853f741ca1SJeff Roberson if ((curthread->td_flags & TDF_IDLETD) != 0) { 2486d2ad694cSJeff Roberson if (tdq->tdq_load > 0) 24873f741ca1SJeff Roberson goto out; 24883f741ca1SJeff Roberson } else 2489d2ad694cSJeff Roberson if (tdq->tdq_load - 1 > 0) 2490b90816f1SJeff Roberson goto out; 2491b90816f1SJeff Roberson load = 0; 2492b90816f1SJeff Roberson out: 2493b90816f1SJeff Roberson return (load); 249435e6168fSJeff Roberson } 249535e6168fSJeff Roberson 2496ae7a6b38SJeff Roberson /* 2497ae7a6b38SJeff Roberson * Choose the highest priority thread to run. The thread is removed from 2498ae7a6b38SJeff Roberson * the run-queue while running however the load remains. For SMP we set 2499ae7a6b38SJeff Roberson * the tdq in the global idle bitmask if it idles here. 2500ae7a6b38SJeff Roberson */ 25017a5e5e2aSJeff Roberson struct thread * 2502c9f25d8fSJeff Roberson sched_choose(void) 2503c9f25d8fSJeff Roberson { 25049727e637SJeff Roberson struct thread *td; 2505ae7a6b38SJeff Roberson struct tdq *tdq; 2506ae7a6b38SJeff Roberson 2507ae7a6b38SJeff Roberson tdq = TDQ_SELF(); 2508ae7a6b38SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED); 25099727e637SJeff Roberson td = tdq_choose(tdq); 25109727e637SJeff Roberson if (td) { 25119727e637SJeff Roberson tdq_runq_rem(tdq, td); 25120502fe2eSJeff Roberson tdq->tdq_lowpri = td->td_priority; 25139727e637SJeff Roberson return (td); 251435e6168fSJeff Roberson } 25150502fe2eSJeff Roberson tdq->tdq_lowpri = PRI_MAX_IDLE; 251662fa74d9SJeff Roberson return (PCPU_GET(idlethread)); 25177a5e5e2aSJeff Roberson } 25187a5e5e2aSJeff Roberson 2519ae7a6b38SJeff Roberson /* 2520ae7a6b38SJeff Roberson * Set owepreempt if necessary. Preemption never happens directly in ULE, 2521ae7a6b38SJeff Roberson * we always request it once we exit a critical section. 2522ae7a6b38SJeff Roberson */ 2523ae7a6b38SJeff Roberson static inline void 2524ae7a6b38SJeff Roberson sched_setpreempt(struct thread *td) 25257a5e5e2aSJeff Roberson { 25267a5e5e2aSJeff Roberson struct thread *ctd; 25277a5e5e2aSJeff Roberson int cpri; 25287a5e5e2aSJeff Roberson int pri; 25297a5e5e2aSJeff Roberson 2530ff256d9cSJeff Roberson THREAD_LOCK_ASSERT(curthread, MA_OWNED); 2531ff256d9cSJeff Roberson 25327a5e5e2aSJeff Roberson ctd = curthread; 25337a5e5e2aSJeff Roberson pri = td->td_priority; 25347a5e5e2aSJeff Roberson cpri = ctd->td_priority; 2535ff256d9cSJeff Roberson if (pri < cpri) 2536ff256d9cSJeff Roberson ctd->td_flags |= TDF_NEEDRESCHED; 2537879e0604SMateusz Guzik if (KERNEL_PANICKED() || pri >= cpri || cold || TD_IS_INHIBITED(ctd)) 2538ae7a6b38SJeff Roberson return; 2539ff256d9cSJeff Roberson if (!sched_shouldpreempt(pri, cpri, 0)) 2540ae7a6b38SJeff Roberson return; 25417a5e5e2aSJeff Roberson ctd->td_owepreempt = 1; 254235e6168fSJeff Roberson } 254335e6168fSJeff Roberson 2544ae7a6b38SJeff Roberson /* 254573daf66fSJeff Roberson * Add a thread to a thread queue. Select the appropriate runq and add the 254673daf66fSJeff Roberson * thread to it. This is the internal function called when the tdq is 254773daf66fSJeff Roberson * predetermined. 2548ae7a6b38SJeff Roberson */ 254935e6168fSJeff Roberson void 2550ae7a6b38SJeff Roberson tdq_add(struct tdq *tdq, struct thread *td, int flags) 255135e6168fSJeff Roberson { 2552c9f25d8fSJeff Roberson 2553ae7a6b38SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED); 255461a74c5cSJeff Roberson THREAD_LOCK_BLOCKED_ASSERT(td, MA_OWNED); 25557a5e5e2aSJeff Roberson KASSERT((td->td_inhibitors == 0), 25567a5e5e2aSJeff Roberson ("sched_add: trying to run inhibited thread")); 25577a5e5e2aSJeff Roberson KASSERT((TD_CAN_RUN(td) || TD_IS_RUNNING(td)), 25587a5e5e2aSJeff Roberson ("sched_add: bad thread state")); 2559b61ce5b0SJeff Roberson KASSERT(td->td_flags & TDF_INMEM, 2560b61ce5b0SJeff Roberson ("sched_add: thread swapped out")); 2561ae7a6b38SJeff Roberson 2562ae7a6b38SJeff Roberson if (td->td_priority < tdq->tdq_lowpri) 2563ae7a6b38SJeff Roberson tdq->tdq_lowpri = td->td_priority; 25649727e637SJeff Roberson tdq_runq_add(tdq, td, flags); 25659727e637SJeff Roberson tdq_load_add(tdq, td); 2566ae7a6b38SJeff Roberson } 2567ae7a6b38SJeff Roberson 2568ae7a6b38SJeff Roberson /* 2569ae7a6b38SJeff Roberson * Select the target thread queue and add a thread to it. Request 2570ae7a6b38SJeff Roberson * preemption or IPI a remote processor if required. 257161a74c5cSJeff Roberson * 257261a74c5cSJeff Roberson * Requires the thread lock on entry, drops on exit. 2573ae7a6b38SJeff Roberson */ 2574ae7a6b38SJeff Roberson void 2575ae7a6b38SJeff Roberson sched_add(struct thread *td, int flags) 2576ae7a6b38SJeff Roberson { 2577ae7a6b38SJeff Roberson struct tdq *tdq; 25787b8bfa0dSJeff Roberson #ifdef SMP 2579ae7a6b38SJeff Roberson int cpu; 2580ae7a6b38SJeff Roberson #endif 25818f51ad55SJeff Roberson 25828f51ad55SJeff Roberson KTR_STATE2(KTR_SCHED, "thread", sched_tdname(td), "runq add", 25838f51ad55SJeff Roberson "prio:%d", td->td_priority, KTR_ATTR_LINKED, 25848f51ad55SJeff Roberson sched_tdname(curthread)); 25858f51ad55SJeff Roberson KTR_POINT1(KTR_SCHED, "thread", sched_tdname(curthread), "wokeup", 25868f51ad55SJeff Roberson KTR_ATTR_LINKED, sched_tdname(td)); 2587b3e9e682SRyan Stone SDT_PROBE4(sched, , , enqueue, td, td->td_proc, NULL, 2588b3e9e682SRyan Stone flags & SRQ_PREEMPTED); 2589ae7a6b38SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 2590ae7a6b38SJeff Roberson /* 2591ae7a6b38SJeff Roberson * Recalculate the priority before we select the target cpu or 2592ae7a6b38SJeff Roberson * run-queue. 2593ae7a6b38SJeff Roberson */ 2594ae7a6b38SJeff Roberson if (PRI_BASE(td->td_pri_class) == PRI_TIMESHARE) 2595ae7a6b38SJeff Roberson sched_priority(td); 2596ae7a6b38SJeff Roberson #ifdef SMP 2597ae7a6b38SJeff Roberson /* 2598ae7a6b38SJeff Roberson * Pick the destination cpu and if it isn't ours transfer to the 2599ae7a6b38SJeff Roberson * target cpu. 2600ae7a6b38SJeff Roberson */ 26019727e637SJeff Roberson cpu = sched_pickcpu(td, flags); 26029727e637SJeff Roberson tdq = sched_setcpu(td, cpu, flags); 2603ae7a6b38SJeff Roberson tdq_add(tdq, td, flags); 260461a74c5cSJeff Roberson if (cpu != PCPU_GET(cpuid)) 260527ee18adSRyan Stone tdq_notify(tdq, td); 260661a74c5cSJeff Roberson else if (!(flags & SRQ_YIELDING)) 260761a74c5cSJeff Roberson sched_setpreempt(td); 2608ae7a6b38SJeff Roberson #else 2609ae7a6b38SJeff Roberson tdq = TDQ_SELF(); 2610ae7a6b38SJeff Roberson /* 2611ae7a6b38SJeff Roberson * Now that the thread is moving to the run-queue, set the lock 2612ae7a6b38SJeff Roberson * to the scheduler's lock. 2613ae7a6b38SJeff Roberson */ 2614e4894505SMark Johnston if (td->td_lock != TDQ_LOCKPTR(tdq)) { 2615e4894505SMark Johnston TDQ_LOCK(tdq); 261661a74c5cSJeff Roberson if ((flags & SRQ_HOLD) != 0) 261761a74c5cSJeff Roberson td->td_lock = TDQ_LOCKPTR(tdq); 261861a74c5cSJeff Roberson else 2619ae7a6b38SJeff Roberson thread_lock_set(td, TDQ_LOCKPTR(tdq)); 2620e4894505SMark Johnston } 2621ae7a6b38SJeff Roberson tdq_add(tdq, td, flags); 2622ae7a6b38SJeff Roberson if (!(flags & SRQ_YIELDING)) 2623ae7a6b38SJeff Roberson sched_setpreempt(td); 262461a74c5cSJeff Roberson #endif 262561a74c5cSJeff Roberson if (!(flags & SRQ_HOLDTD)) 262661a74c5cSJeff Roberson thread_unlock(td); 262735e6168fSJeff Roberson } 262835e6168fSJeff Roberson 2629ae7a6b38SJeff Roberson /* 2630ae7a6b38SJeff Roberson * Remove a thread from a run-queue without running it. This is used 2631ae7a6b38SJeff Roberson * when we're stealing a thread from a remote queue. Otherwise all threads 2632ae7a6b38SJeff Roberson * exit by calling sched_exit_thread() and sched_throw() themselves. 2633ae7a6b38SJeff Roberson */ 263435e6168fSJeff Roberson void 26357cf90fb3SJeff Roberson sched_rem(struct thread *td) 263635e6168fSJeff Roberson { 2637ad1e7d28SJulian Elischer struct tdq *tdq; 26387cf90fb3SJeff Roberson 26398f51ad55SJeff Roberson KTR_STATE1(KTR_SCHED, "thread", sched_tdname(td), "runq rem", 26408f51ad55SJeff Roberson "prio:%d", td->td_priority); 2641b3e9e682SRyan Stone SDT_PROBE3(sched, , , dequeue, td, td->td_proc, NULL); 264293ccd6bfSKonstantin Belousov tdq = TDQ_CPU(td_get_sched(td)->ts_cpu); 2643ae7a6b38SJeff Roberson TDQ_LOCK_ASSERT(tdq, MA_OWNED); 2644ae7a6b38SJeff Roberson MPASS(td->td_lock == TDQ_LOCKPTR(tdq)); 26457a5e5e2aSJeff Roberson KASSERT(TD_ON_RUNQ(td), 2646ad1e7d28SJulian Elischer ("sched_rem: thread not on run queue")); 26479727e637SJeff Roberson tdq_runq_rem(tdq, td); 26489727e637SJeff Roberson tdq_load_rem(tdq, td); 26497a5e5e2aSJeff Roberson TD_SET_CAN_RUN(td); 265062fa74d9SJeff Roberson if (td->td_priority == tdq->tdq_lowpri) 265162fa74d9SJeff Roberson tdq_setlowpri(tdq, NULL); 265235e6168fSJeff Roberson } 265335e6168fSJeff Roberson 2654ae7a6b38SJeff Roberson /* 2655ae7a6b38SJeff Roberson * Fetch cpu utilization information. Updates on demand. 2656ae7a6b38SJeff Roberson */ 265735e6168fSJeff Roberson fixpt_t 26587cf90fb3SJeff Roberson sched_pctcpu(struct thread *td) 265935e6168fSJeff Roberson { 266035e6168fSJeff Roberson fixpt_t pctcpu; 2661ad1e7d28SJulian Elischer struct td_sched *ts; 266235e6168fSJeff Roberson 266335e6168fSJeff Roberson pctcpu = 0; 266493ccd6bfSKonstantin Belousov ts = td_get_sched(td); 266535e6168fSJeff Roberson 26663da35a0aSJohn Baldwin THREAD_LOCK_ASSERT(td, MA_OWNED); 26677295465eSAlexander Motin sched_pctcpu_update(ts, TD_IS_RUNNING(td)); 2668ad1e7d28SJulian Elischer if (ts->ts_ticks) { 266935e6168fSJeff Roberson int rtick; 267035e6168fSJeff Roberson 267135e6168fSJeff Roberson /* How many rtick per second ? */ 2672e7d50326SJeff Roberson rtick = min(SCHED_TICK_HZ(ts) / SCHED_TICK_SECS, hz); 2673e7d50326SJeff Roberson pctcpu = (FSCALE * ((FSCALE * rtick)/hz)) >> FSHIFT; 267435e6168fSJeff Roberson } 267535e6168fSJeff Roberson 267635e6168fSJeff Roberson return (pctcpu); 267735e6168fSJeff Roberson } 267835e6168fSJeff Roberson 267962fa74d9SJeff Roberson /* 268062fa74d9SJeff Roberson * Enforce affinity settings for a thread. Called after adjustments to 268162fa74d9SJeff Roberson * cpumask. 268262fa74d9SJeff Roberson */ 2683885d51a3SJeff Roberson void 2684885d51a3SJeff Roberson sched_affinity(struct thread *td) 2685885d51a3SJeff Roberson { 268662fa74d9SJeff Roberson #ifdef SMP 268762fa74d9SJeff Roberson struct td_sched *ts; 268862fa74d9SJeff Roberson 268962fa74d9SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 269093ccd6bfSKonstantin Belousov ts = td_get_sched(td); 269162fa74d9SJeff Roberson if (THREAD_CAN_SCHED(td, ts->ts_cpu)) 269262fa74d9SJeff Roberson return; 269353a6c8b3SJeff Roberson if (TD_ON_RUNQ(td)) { 269453a6c8b3SJeff Roberson sched_rem(td); 2695d8d5f036SJeff Roberson sched_add(td, SRQ_BORING | SRQ_HOLDTD); 269653a6c8b3SJeff Roberson return; 269753a6c8b3SJeff Roberson } 269862fa74d9SJeff Roberson if (!TD_IS_RUNNING(td)) 269962fa74d9SJeff Roberson return; 270062fa74d9SJeff Roberson /* 27010f7a0ebdSMatthew D Fleming * Force a switch before returning to userspace. If the 27020f7a0ebdSMatthew D Fleming * target thread is not running locally send an ipi to force 27030f7a0ebdSMatthew D Fleming * the issue. 270462fa74d9SJeff Roberson */ 2705a8103ae8SJohn Baldwin td->td_flags |= TDF_NEEDRESCHED; 27060f7a0ebdSMatthew D Fleming if (td != curthread) 27070f7a0ebdSMatthew D Fleming ipi_cpu(ts->ts_cpu, IPI_PREEMPT); 270862fa74d9SJeff Roberson #endif 2709885d51a3SJeff Roberson } 2710885d51a3SJeff Roberson 2711ae7a6b38SJeff Roberson /* 2712ae7a6b38SJeff Roberson * Bind a thread to a target cpu. 2713ae7a6b38SJeff Roberson */ 27149bacd788SJeff Roberson void 27159bacd788SJeff Roberson sched_bind(struct thread *td, int cpu) 27169bacd788SJeff Roberson { 2717ad1e7d28SJulian Elischer struct td_sched *ts; 27189bacd788SJeff Roberson 2719c47f202bSJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED|MA_NOTRECURSED); 27201d7830edSJohn Baldwin KASSERT(td == curthread, ("sched_bind: can only bind curthread")); 272193ccd6bfSKonstantin Belousov ts = td_get_sched(td); 27226b2f763fSJeff Roberson if (ts->ts_flags & TSF_BOUND) 2723c95d2db2SJeff Roberson sched_unbind(td); 27240f7a0ebdSMatthew D Fleming KASSERT(THREAD_CAN_MIGRATE(td), ("%p must be migratable", td)); 2725ad1e7d28SJulian Elischer ts->ts_flags |= TSF_BOUND; 27266b2f763fSJeff Roberson sched_pin(); 272780f86c9fSJeff Roberson if (PCPU_GET(cpuid) == cpu) 27289bacd788SJeff Roberson return; 27296b2f763fSJeff Roberson ts->ts_cpu = cpu; 27309bacd788SJeff Roberson /* When we return from mi_switch we'll be on the correct cpu. */ 2731686bcb5cSJeff Roberson mi_switch(SW_VOL); 2732686bcb5cSJeff Roberson thread_lock(td); 27339bacd788SJeff Roberson } 27349bacd788SJeff Roberson 2735ae7a6b38SJeff Roberson /* 2736ae7a6b38SJeff Roberson * Release a bound thread. 2737ae7a6b38SJeff Roberson */ 27389bacd788SJeff Roberson void 27399bacd788SJeff Roberson sched_unbind(struct thread *td) 27409bacd788SJeff Roberson { 2741e7d50326SJeff Roberson struct td_sched *ts; 2742e7d50326SJeff Roberson 27437b20fb19SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 27441d7830edSJohn Baldwin KASSERT(td == curthread, ("sched_unbind: can only bind curthread")); 274593ccd6bfSKonstantin Belousov ts = td_get_sched(td); 27466b2f763fSJeff Roberson if ((ts->ts_flags & TSF_BOUND) == 0) 27476b2f763fSJeff Roberson return; 2748e7d50326SJeff Roberson ts->ts_flags &= ~TSF_BOUND; 2749e7d50326SJeff Roberson sched_unpin(); 27509bacd788SJeff Roberson } 27519bacd788SJeff Roberson 275235e6168fSJeff Roberson int 2753ebccf1e3SJoseph Koshy sched_is_bound(struct thread *td) 2754ebccf1e3SJoseph Koshy { 27557b20fb19SJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 275693ccd6bfSKonstantin Belousov return (td_get_sched(td)->ts_flags & TSF_BOUND); 2757ebccf1e3SJoseph Koshy } 2758ebccf1e3SJoseph Koshy 2759ae7a6b38SJeff Roberson /* 2760ae7a6b38SJeff Roberson * Basic yield call. 2761ae7a6b38SJeff Roberson */ 276236ec198bSDavid Xu void 276336ec198bSDavid Xu sched_relinquish(struct thread *td) 276436ec198bSDavid Xu { 27657b20fb19SJeff Roberson thread_lock(td); 2766686bcb5cSJeff Roberson mi_switch(SW_VOL | SWT_RELINQUISH); 276736ec198bSDavid Xu } 276836ec198bSDavid Xu 2769ae7a6b38SJeff Roberson /* 2770ae7a6b38SJeff Roberson * Return the total system load. 2771ae7a6b38SJeff Roberson */ 2772ebccf1e3SJoseph Koshy int 277333916c36SJeff Roberson sched_load(void) 277433916c36SJeff Roberson { 277533916c36SJeff Roberson #ifdef SMP 277633916c36SJeff Roberson int total; 277733916c36SJeff Roberson int i; 277833916c36SJeff Roberson 277933916c36SJeff Roberson total = 0; 27803aa6d94eSJohn Baldwin CPU_FOREACH(i) 278162fa74d9SJeff Roberson total += TDQ_CPU(i)->tdq_sysload; 278233916c36SJeff Roberson return (total); 278333916c36SJeff Roberson #else 2784d2ad694cSJeff Roberson return (TDQ_SELF()->tdq_sysload); 278533916c36SJeff Roberson #endif 278633916c36SJeff Roberson } 278733916c36SJeff Roberson 278833916c36SJeff Roberson int 278935e6168fSJeff Roberson sched_sizeof_proc(void) 279035e6168fSJeff Roberson { 279135e6168fSJeff Roberson return (sizeof(struct proc)); 279235e6168fSJeff Roberson } 279335e6168fSJeff Roberson 279435e6168fSJeff Roberson int 279535e6168fSJeff Roberson sched_sizeof_thread(void) 279635e6168fSJeff Roberson { 279735e6168fSJeff Roberson return (sizeof(struct thread) + sizeof(struct td_sched)); 279835e6168fSJeff Roberson } 2799b41f1452SDavid Xu 280009c8a4ccSJeff Roberson #ifdef SMP 280109c8a4ccSJeff Roberson #define TDQ_IDLESPIN(tdq) \ 280209c8a4ccSJeff Roberson ((tdq)->tdq_cg != NULL && ((tdq)->tdq_cg->cg_flags & CG_FLAG_THREAD) == 0) 280309c8a4ccSJeff Roberson #else 280409c8a4ccSJeff Roberson #define TDQ_IDLESPIN(tdq) 1 280509c8a4ccSJeff Roberson #endif 280609c8a4ccSJeff Roberson 28077a5e5e2aSJeff Roberson /* 28087a5e5e2aSJeff Roberson * The actual idle process. 28097a5e5e2aSJeff Roberson */ 28107a5e5e2aSJeff Roberson void 28117a5e5e2aSJeff Roberson sched_idletd(void *dummy) 28127a5e5e2aSJeff Roberson { 28137a5e5e2aSJeff Roberson struct thread *td; 2814ae7a6b38SJeff Roberson struct tdq *tdq; 28152c27cb3aSAlexander Motin int oldswitchcnt, switchcnt; 28161690c6c1SJeff Roberson int i; 28177a5e5e2aSJeff Roberson 28187b55ab05SJeff Roberson mtx_assert(&Giant, MA_NOTOWNED); 28197a5e5e2aSJeff Roberson td = curthread; 2820ae7a6b38SJeff Roberson tdq = TDQ_SELF(); 2821ba96d2d8SJohn Baldwin THREAD_NO_SLEEPING(); 28222c27cb3aSAlexander Motin oldswitchcnt = -1; 2823ae7a6b38SJeff Roberson for (;;) { 28242c27cb3aSAlexander Motin if (tdq->tdq_load) { 28252c27cb3aSAlexander Motin thread_lock(td); 2826686bcb5cSJeff Roberson mi_switch(SW_VOL | SWT_IDLE); 28272c27cb3aSAlexander Motin } 28282c27cb3aSAlexander Motin switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt; 2829ae7a6b38SJeff Roberson #ifdef SMP 283097e9382dSDon Lewis if (always_steal || switchcnt != oldswitchcnt) { 28312c27cb3aSAlexander Motin oldswitchcnt = switchcnt; 28321690c6c1SJeff Roberson if (tdq_idled(tdq) == 0) 28331690c6c1SJeff Roberson continue; 28342c27cb3aSAlexander Motin } 28351690c6c1SJeff Roberson switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt; 28362fd4047fSAlexander Motin #else 28372fd4047fSAlexander Motin oldswitchcnt = switchcnt; 28382fd4047fSAlexander Motin #endif 28391690c6c1SJeff Roberson /* 28401690c6c1SJeff Roberson * If we're switching very frequently, spin while checking 28411690c6c1SJeff Roberson * for load rather than entering a low power state that 28427b55ab05SJeff Roberson * may require an IPI. However, don't do any busy 28437b55ab05SJeff Roberson * loops while on SMT machines as this simply steals 28447b55ab05SJeff Roberson * cycles from cores doing useful work. 28451690c6c1SJeff Roberson */ 284609c8a4ccSJeff Roberson if (TDQ_IDLESPIN(tdq) && switchcnt > sched_idlespinthresh) { 28471690c6c1SJeff Roberson for (i = 0; i < sched_idlespins; i++) { 28481690c6c1SJeff Roberson if (tdq->tdq_load) 28491690c6c1SJeff Roberson break; 28501690c6c1SJeff Roberson cpu_spinwait(); 28511690c6c1SJeff Roberson } 28521690c6c1SJeff Roberson } 28532c27cb3aSAlexander Motin 28542c27cb3aSAlexander Motin /* If there was context switch during spin, restart it. */ 28556c47aaaeSJeff Roberson switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt; 28562c27cb3aSAlexander Motin if (tdq->tdq_load != 0 || switchcnt != oldswitchcnt) 28572c27cb3aSAlexander Motin continue; 28582c27cb3aSAlexander Motin 28592c27cb3aSAlexander Motin /* Run main MD idle handler. */ 28609f9ad565SAlexander Motin tdq->tdq_cpu_idle = 1; 286179654969SAlexander Motin /* 286279654969SAlexander Motin * Make sure that tdq_cpu_idle update is globally visible 286379654969SAlexander Motin * before cpu_idle() read tdq_load. The order is important 286479654969SAlexander Motin * to avoid race with tdq_notify. 286579654969SAlexander Motin */ 2866e8677f38SKonstantin Belousov atomic_thread_fence_seq_cst(); 286797e9382dSDon Lewis /* 286897e9382dSDon Lewis * Checking for again after the fence picks up assigned 286997e9382dSDon Lewis * threads often enough to make it worthwhile to do so in 287097e9382dSDon Lewis * order to avoid calling cpu_idle(). 287197e9382dSDon Lewis */ 287297e9382dSDon Lewis if (tdq->tdq_load != 0) { 287397e9382dSDon Lewis tdq->tdq_cpu_idle = 0; 287497e9382dSDon Lewis continue; 287597e9382dSDon Lewis } 28762c27cb3aSAlexander Motin cpu_idle(switchcnt * 4 > sched_idlespinthresh); 28779f9ad565SAlexander Motin tdq->tdq_cpu_idle = 0; 28782c27cb3aSAlexander Motin 28792c27cb3aSAlexander Motin /* 28802c27cb3aSAlexander Motin * Account thread-less hardware interrupts and 28812c27cb3aSAlexander Motin * other wakeup reasons equal to context switches. 28822c27cb3aSAlexander Motin */ 28832c27cb3aSAlexander Motin switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt; 28842c27cb3aSAlexander Motin if (switchcnt != oldswitchcnt) 28852c27cb3aSAlexander Motin continue; 28862c27cb3aSAlexander Motin tdq->tdq_switchcnt++; 28872c27cb3aSAlexander Motin oldswitchcnt++; 2888ae7a6b38SJeff Roberson } 2889b41f1452SDavid Xu } 2890e7d50326SJeff Roberson 28917b20fb19SJeff Roberson /* 28927b20fb19SJeff Roberson * A CPU is entering for the first time or a thread is exiting. 28937b20fb19SJeff Roberson */ 28947b20fb19SJeff Roberson void 28957b20fb19SJeff Roberson sched_throw(struct thread *td) 28967b20fb19SJeff Roberson { 289759c68134SJeff Roberson struct thread *newtd; 2898ae7a6b38SJeff Roberson struct tdq *tdq; 2899ae7a6b38SJeff Roberson 29001eb13fceSJeff Roberson if (__predict_false(td == NULL)) { 2901018ff686SJeff Roberson #ifdef SMP 2902018ff686SJeff Roberson PCPU_SET(sched, DPCPU_PTR(tdq)); 2903018ff686SJeff Roberson #endif 2904ae7a6b38SJeff Roberson /* Correct spinlock nesting and acquire the correct lock. */ 2905018ff686SJeff Roberson tdq = TDQ_SELF(); 2906ae7a6b38SJeff Roberson TDQ_LOCK(tdq); 29077b20fb19SJeff Roberson spinlock_exit(); 29087e3a96eaSJohn Baldwin PCPU_SET(switchtime, cpu_ticks()); 29097e3a96eaSJohn Baldwin PCPU_SET(switchticks, ticks); 2910e1504695SJeff Roberson PCPU_GET(idlethread)->td_lock = TDQ_LOCKPTR(tdq); 29117b20fb19SJeff Roberson } else { 2912018ff686SJeff Roberson tdq = TDQ_SELF(); 2913686bcb5cSJeff Roberson THREAD_LOCK_ASSERT(td, MA_OWNED); 2914686bcb5cSJeff Roberson THREAD_LOCKPTR_ASSERT(td, TDQ_LOCKPTR(tdq)); 29159727e637SJeff Roberson tdq_load_rem(tdq, td); 291692de34dfSJohn Baldwin td->td_lastcpu = td->td_oncpu; 291792de34dfSJohn Baldwin td->td_oncpu = NOCPU; 29181eb13fceSJeff Roberson thread_lock_block(td); 29197b20fb19SJeff Roberson } 292059c68134SJeff Roberson newtd = choosethread(); 2921686bcb5cSJeff Roberson spinlock_enter(); 2922686bcb5cSJeff Roberson TDQ_UNLOCK(tdq); 2923686bcb5cSJeff Roberson KASSERT(curthread->td_md.md_spinlock_count == 1, 2924686bcb5cSJeff Roberson ("invalid count %d", curthread->td_md.md_spinlock_count)); 29251eb13fceSJeff Roberson /* doesn't return */ 29261eb13fceSJeff Roberson if (__predict_false(td == NULL)) 292759c68134SJeff Roberson cpu_throw(td, newtd); /* doesn't return */ 29281eb13fceSJeff Roberson else 29291eb13fceSJeff Roberson cpu_switch(td, newtd, TDQ_LOCKPTR(tdq)); 29307b20fb19SJeff Roberson } 29317b20fb19SJeff Roberson 2932ae7a6b38SJeff Roberson /* 2933ae7a6b38SJeff Roberson * This is called from fork_exit(). Just acquire the correct locks and 2934ae7a6b38SJeff Roberson * let fork do the rest of the work. 2935ae7a6b38SJeff Roberson */ 29367b20fb19SJeff Roberson void 2937fe54587fSJeff Roberson sched_fork_exit(struct thread *td) 29387b20fb19SJeff Roberson { 2939ae7a6b38SJeff Roberson struct tdq *tdq; 2940ae7a6b38SJeff Roberson int cpuid; 29417b20fb19SJeff Roberson 29427b20fb19SJeff Roberson /* 29437b20fb19SJeff Roberson * Finish setting up thread glue so that it begins execution in a 2944ae7a6b38SJeff Roberson * non-nested critical section with the scheduler lock held. 29457b20fb19SJeff Roberson */ 2946686bcb5cSJeff Roberson KASSERT(curthread->td_md.md_spinlock_count == 1, 2947686bcb5cSJeff Roberson ("invalid count %d", curthread->td_md.md_spinlock_count)); 2948ae7a6b38SJeff Roberson cpuid = PCPU_GET(cpuid); 2949018ff686SJeff Roberson tdq = TDQ_SELF(); 2950686bcb5cSJeff Roberson TDQ_LOCK(tdq); 2951686bcb5cSJeff Roberson spinlock_exit(); 2952ae7a6b38SJeff Roberson MPASS(td->td_lock == TDQ_LOCKPTR(tdq)); 2953ae7a6b38SJeff Roberson td->td_oncpu = cpuid; 295428ef18b8SAndriy Gapon KTR_STATE1(KTR_SCHED, "thread", sched_tdname(td), "running", 295528ef18b8SAndriy Gapon "prio:%d", td->td_priority); 295628ef18b8SAndriy Gapon SDT_PROBE0(sched, , , on__cpu); 29577b20fb19SJeff Roberson } 29587b20fb19SJeff Roberson 29598f51ad55SJeff Roberson /* 29608f51ad55SJeff Roberson * Create on first use to catch odd startup conditons. 29618f51ad55SJeff Roberson */ 29628f51ad55SJeff Roberson char * 29638f51ad55SJeff Roberson sched_tdname(struct thread *td) 29648f51ad55SJeff Roberson { 29658f51ad55SJeff Roberson #ifdef KTR 29668f51ad55SJeff Roberson struct td_sched *ts; 29678f51ad55SJeff Roberson 296893ccd6bfSKonstantin Belousov ts = td_get_sched(td); 29698f51ad55SJeff Roberson if (ts->ts_name[0] == '\0') 29708f51ad55SJeff Roberson snprintf(ts->ts_name, sizeof(ts->ts_name), 29718f51ad55SJeff Roberson "%s tid %d", td->td_name, td->td_tid); 29728f51ad55SJeff Roberson return (ts->ts_name); 29738f51ad55SJeff Roberson #else 29748f51ad55SJeff Roberson return (td->td_name); 29758f51ad55SJeff Roberson #endif 29768f51ad55SJeff Roberson } 29778f51ad55SJeff Roberson 297844ad5475SJohn Baldwin #ifdef KTR 297944ad5475SJohn Baldwin void 298044ad5475SJohn Baldwin sched_clear_tdname(struct thread *td) 298144ad5475SJohn Baldwin { 298244ad5475SJohn Baldwin struct td_sched *ts; 298344ad5475SJohn Baldwin 298493ccd6bfSKonstantin Belousov ts = td_get_sched(td); 298544ad5475SJohn Baldwin ts->ts_name[0] = '\0'; 298644ad5475SJohn Baldwin } 298744ad5475SJohn Baldwin #endif 298844ad5475SJohn Baldwin 298907095abfSIvan Voras #ifdef SMP 299007095abfSIvan Voras 299107095abfSIvan Voras /* 299207095abfSIvan Voras * Build the CPU topology dump string. Is recursively called to collect 299307095abfSIvan Voras * the topology tree. 299407095abfSIvan Voras */ 299507095abfSIvan Voras static int 299607095abfSIvan Voras sysctl_kern_sched_topology_spec_internal(struct sbuf *sb, struct cpu_group *cg, 299707095abfSIvan Voras int indent) 299807095abfSIvan Voras { 299971a19bdcSAttilio Rao char cpusetbuf[CPUSETBUFSIZ]; 300007095abfSIvan Voras int i, first; 300107095abfSIvan Voras 300207095abfSIvan Voras sbuf_printf(sb, "%*s<group level=\"%d\" cache-level=\"%d\">\n", indent, 300319b8a6dbSAndriy Gapon "", 1 + indent / 2, cg->cg_level); 300471a19bdcSAttilio Rao sbuf_printf(sb, "%*s <cpu count=\"%d\" mask=\"%s\">", indent, "", 300571a19bdcSAttilio Rao cg->cg_count, cpusetobj_strprint(cpusetbuf, &cg->cg_mask)); 300607095abfSIvan Voras first = TRUE; 3007aefe0a8cSAlexander Motin for (i = cg->cg_first; i <= cg->cg_last; i++) { 300871a19bdcSAttilio Rao if (CPU_ISSET(i, &cg->cg_mask)) { 300907095abfSIvan Voras if (!first) 301007095abfSIvan Voras sbuf_printf(sb, ", "); 301107095abfSIvan Voras else 301207095abfSIvan Voras first = FALSE; 301307095abfSIvan Voras sbuf_printf(sb, "%d", i); 301407095abfSIvan Voras } 301507095abfSIvan Voras } 301607095abfSIvan Voras sbuf_printf(sb, "</cpu>\n"); 301707095abfSIvan Voras 301807095abfSIvan Voras if (cg->cg_flags != 0) { 3019611daf7eSIvan Voras sbuf_printf(sb, "%*s <flags>", indent, ""); 302007095abfSIvan Voras if ((cg->cg_flags & CG_FLAG_HTT) != 0) 30215368befbSIvan Voras sbuf_printf(sb, "<flag name=\"HTT\">HTT group</flag>"); 3022a401f2d0SIvan Voras if ((cg->cg_flags & CG_FLAG_THREAD) != 0) 3023a401f2d0SIvan Voras sbuf_printf(sb, "<flag name=\"THREAD\">THREAD group</flag>"); 30247b55ab05SJeff Roberson if ((cg->cg_flags & CG_FLAG_SMT) != 0) 3025a401f2d0SIvan Voras sbuf_printf(sb, "<flag name=\"SMT\">SMT group</flag>"); 302607095abfSIvan Voras sbuf_printf(sb, "</flags>\n"); 3027611daf7eSIvan Voras } 302807095abfSIvan Voras 302907095abfSIvan Voras if (cg->cg_children > 0) { 303007095abfSIvan Voras sbuf_printf(sb, "%*s <children>\n", indent, ""); 303107095abfSIvan Voras for (i = 0; i < cg->cg_children; i++) 303207095abfSIvan Voras sysctl_kern_sched_topology_spec_internal(sb, 303307095abfSIvan Voras &cg->cg_child[i], indent+2); 303407095abfSIvan Voras sbuf_printf(sb, "%*s </children>\n", indent, ""); 303507095abfSIvan Voras } 303607095abfSIvan Voras sbuf_printf(sb, "%*s</group>\n", indent, ""); 303707095abfSIvan Voras return (0); 303807095abfSIvan Voras } 303907095abfSIvan Voras 304007095abfSIvan Voras /* 304107095abfSIvan Voras * Sysctl handler for retrieving topology dump. It's a wrapper for 304207095abfSIvan Voras * the recursive sysctl_kern_smp_topology_spec_internal(). 304307095abfSIvan Voras */ 304407095abfSIvan Voras static int 304507095abfSIvan Voras sysctl_kern_sched_topology_spec(SYSCTL_HANDLER_ARGS) 304607095abfSIvan Voras { 304707095abfSIvan Voras struct sbuf *topo; 304807095abfSIvan Voras int err; 304907095abfSIvan Voras 305007095abfSIvan Voras KASSERT(cpu_top != NULL, ("cpu_top isn't initialized")); 305107095abfSIvan Voras 3052b97fa22cSIan Lepore topo = sbuf_new_for_sysctl(NULL, NULL, 512, req); 305307095abfSIvan Voras if (topo == NULL) 305407095abfSIvan Voras return (ENOMEM); 305507095abfSIvan Voras 305607095abfSIvan Voras sbuf_printf(topo, "<groups>\n"); 305707095abfSIvan Voras err = sysctl_kern_sched_topology_spec_internal(topo, cpu_top, 1); 305807095abfSIvan Voras sbuf_printf(topo, "</groups>\n"); 305907095abfSIvan Voras 306007095abfSIvan Voras if (err == 0) { 3061b97fa22cSIan Lepore err = sbuf_finish(topo); 306207095abfSIvan Voras } 306307095abfSIvan Voras sbuf_delete(topo); 306407095abfSIvan Voras return (err); 306507095abfSIvan Voras } 3066b67cc292SDavid Xu 306707095abfSIvan Voras #endif 306807095abfSIvan Voras 3069579895dfSAlexander Motin static int 3070579895dfSAlexander Motin sysctl_kern_quantum(SYSCTL_HANDLER_ARGS) 3071579895dfSAlexander Motin { 3072579895dfSAlexander Motin int error, new_val, period; 3073579895dfSAlexander Motin 3074579895dfSAlexander Motin period = 1000000 / realstathz; 3075579895dfSAlexander Motin new_val = period * sched_slice; 3076579895dfSAlexander Motin error = sysctl_handle_int(oidp, &new_val, 0, req); 3077579895dfSAlexander Motin if (error != 0 || req->newptr == NULL) 3078579895dfSAlexander Motin return (error); 3079579895dfSAlexander Motin if (new_val <= 0) 3080579895dfSAlexander Motin return (EINVAL); 308137f4e025SAlexander Motin sched_slice = imax(1, (new_val + period / 2) / period); 30825e5c3873SJeff Roberson sched_slice_min = sched_slice / SCHED_SLICE_MIN_DIVISOR; 308337f4e025SAlexander Motin hogticks = imax(1, (2 * hz * sched_slice + realstathz / 2) / 308437f4e025SAlexander Motin realstathz); 3085579895dfSAlexander Motin return (0); 3086579895dfSAlexander Motin } 3087579895dfSAlexander Motin 30887029da5cSPawel Biernacki SYSCTL_NODE(_kern, OID_AUTO, sched, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 30897029da5cSPawel Biernacki "Scheduler"); 3090ae7a6b38SJeff Roberson SYSCTL_STRING(_kern_sched, OID_AUTO, name, CTLFLAG_RD, "ULE", 0, 3091e7d50326SJeff Roberson "Scheduler name"); 30927029da5cSPawel Biernacki SYSCTL_PROC(_kern_sched, OID_AUTO, quantum, 30937029da5cSPawel Biernacki CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, NULL, 0, 30947029da5cSPawel Biernacki sysctl_kern_quantum, "I", 309537f4e025SAlexander Motin "Quantum for timeshare threads in microseconds"); 3096ae7a6b38SJeff Roberson SYSCTL_INT(_kern_sched, OID_AUTO, slice, CTLFLAG_RW, &sched_slice, 0, 309737f4e025SAlexander Motin "Quantum for timeshare threads in stathz ticks"); 3098ae7a6b38SJeff Roberson SYSCTL_INT(_kern_sched, OID_AUTO, interact, CTLFLAG_RW, &sched_interact, 0, 3099ae7a6b38SJeff Roberson "Interactivity score threshold"); 310037f4e025SAlexander Motin SYSCTL_INT(_kern_sched, OID_AUTO, preempt_thresh, CTLFLAG_RW, 310137f4e025SAlexander Motin &preempt_thresh, 0, 310237f4e025SAlexander Motin "Maximal (lowest) priority for preemption"); 310337f4e025SAlexander Motin SYSCTL_INT(_kern_sched, OID_AUTO, static_boost, CTLFLAG_RW, &static_boost, 0, 310437f4e025SAlexander Motin "Assign static kernel priorities to sleeping threads"); 310537f4e025SAlexander Motin SYSCTL_INT(_kern_sched, OID_AUTO, idlespins, CTLFLAG_RW, &sched_idlespins, 0, 310637f4e025SAlexander Motin "Number of times idle thread will spin waiting for new work"); 310737f4e025SAlexander Motin SYSCTL_INT(_kern_sched, OID_AUTO, idlespinthresh, CTLFLAG_RW, 310837f4e025SAlexander Motin &sched_idlespinthresh, 0, 310937f4e025SAlexander Motin "Threshold before we will permit idle thread spinning"); 31107b8bfa0dSJeff Roberson #ifdef SMP 3111ae7a6b38SJeff Roberson SYSCTL_INT(_kern_sched, OID_AUTO, affinity, CTLFLAG_RW, &affinity, 0, 3112ae7a6b38SJeff Roberson "Number of hz ticks to keep thread affinity for"); 3113ae7a6b38SJeff Roberson SYSCTL_INT(_kern_sched, OID_AUTO, balance, CTLFLAG_RW, &rebalance, 0, 3114ae7a6b38SJeff Roberson "Enables the long-term load balancer"); 31157fcf154aSJeff Roberson SYSCTL_INT(_kern_sched, OID_AUTO, balance_interval, CTLFLAG_RW, 31167fcf154aSJeff Roberson &balance_interval, 0, 3117579895dfSAlexander Motin "Average period in stathz ticks to run the long-term balancer"); 3118ae7a6b38SJeff Roberson SYSCTL_INT(_kern_sched, OID_AUTO, steal_idle, CTLFLAG_RW, &steal_idle, 0, 3119ae7a6b38SJeff Roberson "Attempts to steal work from other cores before idling"); 312028994a58SJeff Roberson SYSCTL_INT(_kern_sched, OID_AUTO, steal_thresh, CTLFLAG_RW, &steal_thresh, 0, 312137f4e025SAlexander Motin "Minimum load on remote CPU before we'll steal"); 312297e9382dSDon Lewis SYSCTL_INT(_kern_sched, OID_AUTO, trysteal_limit, CTLFLAG_RW, &trysteal_limit, 312397e9382dSDon Lewis 0, "Topological distance limit for stealing threads in sched_switch()"); 312497e9382dSDon Lewis SYSCTL_INT(_kern_sched, OID_AUTO, always_steal, CTLFLAG_RW, &always_steal, 0, 312597e9382dSDon Lewis "Always run the stealer from the idle thread"); 312607095abfSIvan Voras SYSCTL_PROC(_kern_sched, OID_AUTO, topology_spec, CTLTYPE_STRING | 3127c69a1a50SMateusz Guzik CTLFLAG_MPSAFE | CTLFLAG_RD, NULL, 0, sysctl_kern_sched_topology_spec, "A", 312807095abfSIvan Voras "XML dump of detected CPU topology"); 31297b8bfa0dSJeff Roberson #endif 3130e7d50326SJeff Roberson 313154b0e65fSJeff Roberson /* ps compat. All cpu percentages from ULE are weighted. */ 3132a5423ea3SJeff Roberson static int ccpu = 0; 3133b05ca429SPawel Biernacki SYSCTL_INT(_kern, OID_AUTO, ccpu, CTLFLAG_RD, &ccpu, 0, 3134b05ca429SPawel Biernacki "Decay factor used for updating %CPU in 4BSD scheduler"); 3135