1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1980, 1986, 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)param.c 8.3 (Berkeley) 8/20/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_param.h" 43 #include "opt_msgbuf.h" 44 #include "opt_maxusers.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/buf.h> 49 #include <sys/kernel.h> 50 #include <sys/limits.h> 51 #include <sys/msgbuf.h> 52 #include <sys/sysctl.h> 53 #include <sys/proc.h> 54 #include <sys/vnode.h> 55 56 #include <vm/vm.h> 57 #include <vm/vm_param.h> 58 #include <vm/pmap.h> 59 60 /* 61 * System parameter formulae. 62 */ 63 64 #ifndef HZ 65 # if defined(__mips__) || defined(__arm__) 66 # define HZ 100 67 # else 68 # define HZ 1000 69 # endif 70 # ifndef HZ_VM 71 # define HZ_VM 100 72 # endif 73 #else 74 # ifndef HZ_VM 75 # define HZ_VM HZ 76 # endif 77 #endif 78 #define NPROC (20 + 16 * maxusers) 79 #ifndef NBUF 80 #define NBUF 0 81 #endif 82 #ifndef MAXFILES 83 #define MAXFILES (40 + 32 * maxusers) 84 #endif 85 86 static int sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS); 87 88 int hz; /* system clock's frequency */ 89 int tick; /* usec per tick (1000000 / hz) */ 90 struct bintime tick_bt; /* bintime per tick (1s / hz) */ 91 sbintime_t tick_sbt; 92 int maxusers; /* base tunable */ 93 int maxproc; /* maximum # of processes */ 94 int maxprocperuid; /* max # of procs per user */ 95 int maxfiles; /* sys. wide open files limit */ 96 int maxfilesperproc; /* per-proc open files limit */ 97 int msgbufsize; /* size of kernel message buffer */ 98 int nbuf; 99 int bio_transient_maxcnt; 100 int ngroups_max; /* max # groups per process */ 101 int nswbuf; 102 pid_t pid_max = PID_MAX; 103 long maxswzone; /* max swmeta KVA storage */ 104 long maxbcache; /* max buffer cache KVA storage */ 105 long maxpipekva; /* Limit on pipe KVA */ 106 int vm_guest = VM_GUEST_NO; /* Running as virtual machine guest? */ 107 u_long maxtsiz; /* max text size */ 108 u_long dfldsiz; /* initial data size limit */ 109 u_long maxdsiz; /* max data size */ 110 u_long dflssiz; /* initial stack size limit */ 111 u_long maxssiz; /* max stack size */ 112 u_long sgrowsiz; /* amount to grow stack */ 113 114 SYSCTL_INT(_kern, OID_AUTO, hz, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &hz, 0, 115 "Number of clock ticks per second"); 116 SYSCTL_INT(_kern, OID_AUTO, nbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nbuf, 0, 117 "Number of buffers in the buffer cache"); 118 SYSCTL_INT(_kern, OID_AUTO, nswbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nswbuf, 0, 119 "Number of swap buffers"); 120 SYSCTL_INT(_kern, OID_AUTO, msgbufsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &msgbufsize, 0, 121 "Size of the kernel message buffer"); 122 SYSCTL_LONG(_kern, OID_AUTO, maxswzone, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxswzone, 0, 123 "Maximum memory for swap metadata"); 124 SYSCTL_LONG(_kern, OID_AUTO, maxbcache, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxbcache, 0, 125 "Maximum value of vfs.maxbufspace"); 126 SYSCTL_INT(_kern, OID_AUTO, bio_transient_maxcnt, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 127 &bio_transient_maxcnt, 0, 128 "Maximum number of transient BIOs mappings"); 129 SYSCTL_ULONG(_kern, OID_AUTO, maxtsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxtsiz, 0, 130 "Maximum text size"); 131 SYSCTL_ULONG(_kern, OID_AUTO, dfldsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dfldsiz, 0, 132 "Initial data size limit"); 133 SYSCTL_ULONG(_kern, OID_AUTO, maxdsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxdsiz, 0, 134 "Maximum data size"); 135 SYSCTL_ULONG(_kern, OID_AUTO, dflssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dflssiz, 0, 136 "Initial stack size limit"); 137 SYSCTL_ULONG(_kern, OID_AUTO, maxssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxssiz, 0, 138 "Maximum stack size"); 139 SYSCTL_ULONG(_kern, OID_AUTO, sgrowsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &sgrowsiz, 0, 140 "Amount to grow stack on a stack fault"); 141 SYSCTL_PROC(_kern, OID_AUTO, vm_guest, 142 CTLFLAG_RD | CTLTYPE_STRING | CTLFLAG_MPSAFE, NULL, 0, 143 sysctl_kern_vm_guest, "A", 144 "Virtual machine guest detected?"); 145 146 /* 147 * The elements of this array are ordered based upon the values of the 148 * corresponding enum VM_GUEST members. 149 */ 150 static const char *const vm_guest_sysctl_names[] = { 151 [VM_GUEST_NO] = "none", 152 [VM_GUEST_VM] = "generic", 153 [VM_GUEST_XEN] = "xen", 154 [VM_GUEST_HV] = "hv", 155 [VM_GUEST_VMWARE] = "vmware", 156 [VM_GUEST_KVM] = "kvm", 157 [VM_GUEST_BHYVE] = "bhyve", 158 [VM_GUEST_VBOX] = "vbox", 159 [VM_GUEST_PARALLELS] = "parallels", 160 [VM_LAST] = NULL 161 }; 162 CTASSERT(nitems(vm_guest_sysctl_names) - 1 == VM_LAST); 163 164 /* 165 * Boot time overrides that are not scaled against main memory 166 */ 167 void 168 init_param1(void) 169 { 170 171 #if !defined(__mips__) && !defined(__arm64__) 172 TUNABLE_INT_FETCH("kern.kstack_pages", &kstack_pages); 173 #endif 174 hz = -1; 175 TUNABLE_INT_FETCH("kern.hz", &hz); 176 if (hz == -1) 177 hz = vm_guest > VM_GUEST_NO ? HZ_VM : HZ; 178 tick = 1000000 / hz; 179 tick_sbt = SBT_1S / hz; 180 tick_bt = sbttobt(tick_sbt); 181 182 /* 183 * Arrange for ticks to wrap 10 minutes after boot to help catch 184 * sign problems sooner. 185 */ 186 ticks = INT_MAX - (hz * 10 * 60); 187 188 vn_lock_pair_pause_max = hz / 100; 189 if (vn_lock_pair_pause_max == 0) 190 vn_lock_pair_pause_max = 1; 191 192 #ifdef VM_SWZONE_SIZE_MAX 193 maxswzone = VM_SWZONE_SIZE_MAX; 194 #endif 195 TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone); 196 #ifdef VM_BCACHE_SIZE_MAX 197 maxbcache = VM_BCACHE_SIZE_MAX; 198 #endif 199 TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache); 200 msgbufsize = MSGBUF_SIZE; 201 TUNABLE_INT_FETCH("kern.msgbufsize", &msgbufsize); 202 203 maxtsiz = MAXTSIZ; 204 TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz); 205 dfldsiz = DFLDSIZ; 206 TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz); 207 maxdsiz = MAXDSIZ; 208 TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz); 209 dflssiz = DFLSSIZ; 210 TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz); 211 maxssiz = MAXSSIZ; 212 TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz); 213 sgrowsiz = SGROWSIZ; 214 TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz); 215 216 /* 217 * Let the administrator set {NGROUPS_MAX}, but disallow values 218 * less than NGROUPS_MAX which would violate POSIX.1-2008 or 219 * greater than INT_MAX-1 which would result in overflow. 220 */ 221 ngroups_max = NGROUPS_MAX; 222 TUNABLE_INT_FETCH("kern.ngroups", &ngroups_max); 223 if (ngroups_max < NGROUPS_MAX) 224 ngroups_max = NGROUPS_MAX; 225 226 /* 227 * Only allow to lower the maximal pid. 228 * Prevent setting up a non-bootable system if pid_max is too low. 229 */ 230 TUNABLE_INT_FETCH("kern.pid_max", &pid_max); 231 if (pid_max > PID_MAX) 232 pid_max = PID_MAX; 233 else if (pid_max < 300) 234 pid_max = 300; 235 236 TUNABLE_INT_FETCH("vfs.unmapped_buf_allowed", &unmapped_buf_allowed); 237 } 238 239 /* 240 * Boot time overrides that are scaled against main memory 241 */ 242 void 243 init_param2(long physpages) 244 { 245 246 /* Base parameters */ 247 maxusers = MAXUSERS; 248 TUNABLE_INT_FETCH("kern.maxusers", &maxusers); 249 if (maxusers == 0) { 250 maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE); 251 if (maxusers < 32) 252 maxusers = 32; 253 #ifdef VM_MAX_AUTOTUNE_MAXUSERS 254 if (maxusers > VM_MAX_AUTOTUNE_MAXUSERS) 255 maxusers = VM_MAX_AUTOTUNE_MAXUSERS; 256 #endif 257 /* 258 * Scales down the function in which maxusers grows once 259 * we hit 384. 260 */ 261 if (maxusers > 384) 262 maxusers = 384 + ((maxusers - 384) / 8); 263 } 264 265 /* 266 * The following can be overridden after boot via sysctl. Note: 267 * unless overriden, these macros are ultimately based on maxusers. 268 * Limit maxproc so that kmap entries cannot be exhausted by 269 * processes. 270 */ 271 maxproc = NPROC; 272 TUNABLE_INT_FETCH("kern.maxproc", &maxproc); 273 if (maxproc > (physpages / 12)) 274 maxproc = physpages / 12; 275 if (maxproc > pid_max) 276 maxproc = pid_max; 277 maxprocperuid = (maxproc * 9) / 10; 278 279 /* 280 * The default limit for maxfiles is 1/12 of the number of 281 * physical page but not less than 16 times maxusers. 282 * At most it can be 1/6 the number of physical pages. 283 */ 284 maxfiles = imax(MAXFILES, physpages / 8); 285 TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles); 286 if (maxfiles > (physpages / 4)) 287 maxfiles = physpages / 4; 288 maxfilesperproc = (maxfiles / 10) * 9; 289 TUNABLE_INT_FETCH("kern.maxfilesperproc", &maxfilesperproc); 290 291 /* 292 * Cannot be changed after boot. 293 */ 294 nbuf = NBUF; 295 TUNABLE_INT_FETCH("kern.nbuf", &nbuf); 296 TUNABLE_INT_FETCH("kern.bio_transient_maxcnt", &bio_transient_maxcnt); 297 298 /* 299 * Physical buffers are pre-allocated buffers (struct buf) that 300 * are used as temporary holders for I/O, such as paging I/O. 301 */ 302 TUNABLE_INT_FETCH("kern.nswbuf", &nswbuf); 303 304 /* 305 * The default for maxpipekva is min(1/64 of the kernel address space, 306 * max(1/64 of main memory, 512KB)). See sys_pipe.c for more details. 307 */ 308 maxpipekva = (physpages / 64) * PAGE_SIZE; 309 TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva); 310 if (maxpipekva < 512 * 1024) 311 maxpipekva = 512 * 1024; 312 if (maxpipekva > (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 64) 313 maxpipekva = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 314 64; 315 } 316 317 /* 318 * Sysctl stringifying handler for kern.vm_guest. 319 */ 320 static int 321 sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS) 322 { 323 return (SYSCTL_OUT_STR(req, vm_guest_sysctl_names[vm_guest])); 324 } 325