/*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1980, 1986, 1989, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include "opt_param.h" #include "opt_msgbuf.h" #include "opt_maxphys.h" #include "opt_maxusers.h" #include #include #include #include #include #include #include #include #include #include #include #include #include /* * System parameter formulae. */ #ifndef HZ # define HZ 1000 # ifndef HZ_VM # define HZ_VM 100 # endif #else # ifndef HZ_VM # define HZ_VM HZ # endif #endif #define NPROC (20 + 16 * maxusers) #ifndef NBUF #define NBUF 0 #endif #ifndef MAXFILES #define MAXFILES (40 + 32 * maxusers) #endif static int sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS); int hz; /* system clock's frequency */ int tick; /* usec per tick (1000000 / hz) */ time_t tick_seconds_max; /* max hz * seconds an integer can hold */ struct bintime tick_bt; /* bintime per tick (1s / hz) */ sbintime_t tick_sbt; int maxusers; /* base tunable */ int maxproc; /* maximum # of processes */ int maxprocperuid; /* max # of procs per user */ int maxfiles; /* sys. wide open files limit */ int maxfilesperproc; /* per-proc open files limit */ int msgbufsize; /* size of kernel message buffer */ int nbuf; /* number of bcache bufs */ int bio_transient_maxcnt; int ngroups_max; /* max # groups per process */ int nswbuf; pid_t pid_max = PID_MAX; u_long maxswzone; /* max swmeta KVA storage */ u_long maxbcache; /* max buffer cache KVA storage */ u_long maxpipekva; /* Limit on pipe KVA */ u_long maxphys; /* max raw I/O transfer size */ int vm_guest = VM_GUEST_NO; /* Running as virtual machine guest? */ u_long maxtsiz; /* max text size */ u_long dfldsiz; /* initial data size limit */ u_long maxdsiz; /* max data size */ u_long dflssiz; /* initial stack size limit */ u_long maxssiz; /* max stack size */ u_long sgrowsiz; /* amount to grow stack */ SYSCTL_INT(_kern, OID_AUTO, hz, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &hz, 0, "Number of clock ticks per second"); SYSCTL_INT(_kern, OID_AUTO, hz_max, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, HZ_MAXIMUM, "Maximum hz value supported"); SYSCTL_INT(_kern, OID_AUTO, hz_min, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, HZ_MINIMUM, "Minimum hz value supported"); SYSCTL_INT(_kern, OID_AUTO, nbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nbuf, 0, "Number of buffers in the buffer cache"); SYSCTL_INT(_kern, OID_AUTO, nswbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nswbuf, 0, "Number of swap buffers"); SYSCTL_INT(_kern, OID_AUTO, msgbufsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &msgbufsize, 0, "Size of the kernel message buffer"); SYSCTL_LONG(_kern, OID_AUTO, maxswzone, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxswzone, 0, "Maximum memory for swap metadata"); SYSCTL_LONG(_kern, OID_AUTO, maxbcache, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxbcache, 0, "Maximum value of vfs.maxbufspace"); SYSCTL_INT(_kern, OID_AUTO, bio_transient_maxcnt, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &bio_transient_maxcnt, 0, "Maximum number of transient BIOs mappings"); SYSCTL_ULONG(_kern, OID_AUTO, maxtsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxtsiz, 0, "Maximum text size"); SYSCTL_ULONG(_kern, OID_AUTO, dfldsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dfldsiz, 0, "Initial data size limit"); SYSCTL_ULONG(_kern, OID_AUTO, maxdsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxdsiz, 0, "Maximum data size"); SYSCTL_ULONG(_kern, OID_AUTO, dflssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dflssiz, 0, "Initial stack size limit"); SYSCTL_ULONG(_kern, OID_AUTO, maxssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxssiz, 0, "Maximum stack size"); SYSCTL_ULONG(_kern, OID_AUTO, sgrowsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &sgrowsiz, 0, "Amount to grow stack on a stack fault"); SYSCTL_PROC(_kern, OID_AUTO, vm_guest, CTLFLAG_RD | CTLTYPE_STRING | CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_vm_guest, "A", "Virtual machine guest detected?"); /* * The elements of this array are ordered based upon the values of the * corresponding enum VM_GUEST members. */ static const char *const vm_guest_sysctl_names[] = { [VM_GUEST_NO] = "none", [VM_GUEST_VM] = "generic", [VM_GUEST_XEN] = "xen", [VM_GUEST_HV] = "hv", [VM_GUEST_VMWARE] = "vmware", [VM_GUEST_KVM] = "kvm", [VM_GUEST_BHYVE] = "bhyve", [VM_GUEST_VBOX] = "vbox", [VM_GUEST_PARALLELS] = "parallels", [VM_GUEST_NVMM] = "nvmm", }; _Static_assert(nitems(vm_guest_sysctl_names) == VM_GUEST_LAST, "new vm guest type not added to vm_guest_sysctl_names"); /* * Boot time overrides that are not scaled against main memory */ void init_param1(void) { TSENTER(); /* * arm64 and riscv currently hard-code the thread0 kstack size * to KSTACK_PAGES, ignoring the tunable. */ TUNABLE_INT_FETCH("kern.kstack_pages", &kstack_pages); hz = -1; TUNABLE_INT_FETCH("kern.hz", &hz); if (hz == -1) hz = vm_guest > VM_GUEST_NO ? HZ_VM : HZ; /* range check the "hz" value */ if (__predict_false(hz < HZ_MINIMUM)) hz = HZ_MINIMUM; else if (__predict_false(hz > HZ_MAXIMUM)) hz = HZ_MAXIMUM; tick = 1000000 / hz; tick_sbt = SBT_1S / hz; tick_bt = sbttobt(tick_sbt); tick_seconds_max = INT_MAX / hz; /* * Arrange for ticks to wrap 10 minutes after boot to help catch * sign problems sooner. */ ticks = INT_MAX - (hz * 10 * 60); vn_lock_pair_pause_max = hz / 100; if (vn_lock_pair_pause_max == 0) vn_lock_pair_pause_max = 1; #ifdef VM_SWZONE_SIZE_MAX maxswzone = VM_SWZONE_SIZE_MAX; #endif TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone); #ifdef VM_BCACHE_SIZE_MAX maxbcache = VM_BCACHE_SIZE_MAX; #endif TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache); msgbufsize = MSGBUF_SIZE; TUNABLE_INT_FETCH("kern.msgbufsize", &msgbufsize); maxtsiz = MAXTSIZ; TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz); dfldsiz = DFLDSIZ; TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz); maxdsiz = MAXDSIZ; TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz); dflssiz = DFLSSIZ; TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz); maxssiz = MAXSSIZ; TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz); sgrowsiz = SGROWSIZ; TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz); /* * Let the administrator set {NGROUPS_MAX}. * * Values less than NGROUPS_MAX would violate POSIX/SuS (see the * specification for , paragraph "Runtime Increasable * Values"). * * On the other hand, INT_MAX would result in an overflow for the common * 'ngroups_max + 1' computation (to obtain the size of the internal * groups array, its first element being reserved for the effective * GID). Also, the number of allocated bytes for the group array must * not overflow on 32-bit machines. For all these reasons, we limit the * number of supplementary groups to some very high number that we * expect will never be reached in all practical uses and ensures we * avoid the problems just exposed, even if 'gid_t' was to be enlarged * by a magnitude. */ ngroups_max = NGROUPS_MAX; TUNABLE_INT_FETCH("kern.ngroups", &ngroups_max); if (ngroups_max < NGROUPS_MAX) ngroups_max = NGROUPS_MAX; else { const int ngroups_max_max = (1 << 24) - 1; if (ngroups_max > ngroups_max_max) ngroups_max = ngroups_max_max; } /* * Only allow to lower the maximal pid. * Prevent setting up a non-bootable system if pid_max is too low. */ TUNABLE_INT_FETCH("kern.pid_max", &pid_max); if (pid_max > PID_MAX) pid_max = PID_MAX; else if (pid_max < 300) pid_max = 300; TUNABLE_INT_FETCH("vfs.unmapped_buf_allowed", &unmapped_buf_allowed); TSEXIT(); } /* * Boot time overrides that are scaled against main memory */ void init_param2(long physpages) { TSENTER(); /* Base parameters */ maxusers = MAXUSERS; TUNABLE_INT_FETCH("kern.maxusers", &maxusers); if (maxusers == 0) { maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE); if (maxusers < 32) maxusers = 32; #ifdef VM_MAX_AUTOTUNE_MAXUSERS if (maxusers > VM_MAX_AUTOTUNE_MAXUSERS) maxusers = VM_MAX_AUTOTUNE_MAXUSERS; #endif /* * Scales down the function in which maxusers grows once * we hit 384. */ if (maxusers > 384) maxusers = 384 + ((maxusers - 384) / 8); } /* * The following can be overridden after boot via sysctl. Note: * unless overridden, these macros are ultimately based on maxusers. * Limit maxproc so that kmap entries cannot be exhausted by * processes. */ maxproc = NPROC; TUNABLE_INT_FETCH("kern.maxproc", &maxproc); if (maxproc > (physpages / 12)) maxproc = physpages / 12; if (maxproc > pid_max) maxproc = pid_max; maxprocperuid = (maxproc * 9) / 10; /* * The default limit for maxfiles is 1/12 of the number of * physical page but not less than 16 times maxusers. * At most it can be 1/6 the number of physical pages. */ maxfiles = imax(MAXFILES, physpages / 8); TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles); if (maxfiles > (physpages / 4)) maxfiles = physpages / 4; maxfilesperproc = (maxfiles / 10) * 9; TUNABLE_INT_FETCH("kern.maxfilesperproc", &maxfilesperproc); /* * Cannot be changed after boot. */ nbuf = NBUF; TUNABLE_INT_FETCH("kern.nbuf", &nbuf); TUNABLE_INT_FETCH("kern.bio_transient_maxcnt", &bio_transient_maxcnt); maxphys = MAXPHYS; TUNABLE_ULONG_FETCH("kern.maxphys", &maxphys); if (maxphys == 0) { maxphys = MAXPHYS; } else if (__bitcountl(maxphys) != 1) { /* power of two */ if (flsl(maxphys) == NBBY * sizeof(maxphys)) maxphys = MAXPHYS; else maxphys = 1UL << flsl(maxphys); } if (maxphys < PAGE_SIZE) maxphys = MAXPHYS; /* * Physical buffers are pre-allocated buffers (struct buf) that * are used as temporary holders for I/O, such as paging I/O. */ TUNABLE_INT_FETCH("kern.nswbuf", &nswbuf); /* * The default for maxpipekva is min(1/64 of the kernel address space, * max(1/64 of main memory, 512KB)). See sys_pipe.c for more details. */ maxpipekva = ptoa(physpages / 64); TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva); if (maxpipekva < 512 * 1024) maxpipekva = 512 * 1024; if (maxpipekva > (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 64) maxpipekva = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 64; TSEXIT(); } /* * Sysctl stringifying handler for kern.vm_guest. */ static int sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS) { return (SYSCTL_OUT_STR(req, vm_guest_sysctl_names[vm_guest])); }