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 55 #include <vm/vm.h> 56 #include <vm/vm_param.h> 57 #include <vm/pmap.h> 58 59 /* 60 * System parameter formulae. 61 */ 62 63 #ifndef HZ 64 # if defined(__mips__) || defined(__arm__) 65 # define HZ 100 66 # else 67 # define HZ 1000 68 # endif 69 # ifndef HZ_VM 70 # define HZ_VM 100 71 # endif 72 #else 73 # ifndef HZ_VM 74 # define HZ_VM HZ 75 # endif 76 #endif 77 #define NPROC (20 + 16 * maxusers) 78 #ifndef NBUF 79 #define NBUF 0 80 #endif 81 #ifndef MAXFILES 82 #define MAXFILES (40 + 32 * maxusers) 83 #endif 84 85 static int sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS); 86 87 int hz; /* system clock's frequency */ 88 int tick; /* usec per tick (1000000 / hz) */ 89 struct bintime tick_bt; /* bintime per tick (1s / hz) */ 90 sbintime_t tick_sbt; 91 int maxusers; /* base tunable */ 92 int maxproc; /* maximum # of processes */ 93 int maxprocperuid; /* max # of procs per user */ 94 int maxfiles; /* sys. wide open files limit */ 95 int maxfilesperproc; /* per-proc open files limit */ 96 int msgbufsize; /* size of kernel message buffer */ 97 int nbuf; 98 int bio_transient_maxcnt; 99 int ngroups_max; /* max # groups per process */ 100 int nswbuf; 101 pid_t pid_max = PID_MAX; 102 long maxswzone; /* max swmeta KVA storage */ 103 long maxbcache; /* max buffer cache KVA storage */ 104 long maxpipekva; /* Limit on pipe KVA */ 105 int vm_guest = VM_GUEST_NO; /* Running as virtual machine guest? */ 106 u_long maxtsiz; /* max text size */ 107 u_long dfldsiz; /* initial data size limit */ 108 u_long maxdsiz; /* max data size */ 109 u_long dflssiz; /* initial stack size limit */ 110 u_long maxssiz; /* max stack size */ 111 u_long sgrowsiz; /* amount to grow stack */ 112 113 SYSCTL_INT(_kern, OID_AUTO, hz, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &hz, 0, 114 "Number of clock ticks per second"); 115 SYSCTL_INT(_kern, OID_AUTO, nbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nbuf, 0, 116 "Number of buffers in the buffer cache"); 117 SYSCTL_INT(_kern, OID_AUTO, nswbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nswbuf, 0, 118 "Number of swap buffers"); 119 SYSCTL_INT(_kern, OID_AUTO, msgbufsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &msgbufsize, 0, 120 "Size of the kernel message buffer"); 121 SYSCTL_LONG(_kern, OID_AUTO, maxswzone, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxswzone, 0, 122 "Maximum memory for swap metadata"); 123 SYSCTL_LONG(_kern, OID_AUTO, maxbcache, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxbcache, 0, 124 "Maximum value of vfs.maxbufspace"); 125 SYSCTL_INT(_kern, OID_AUTO, bio_transient_maxcnt, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 126 &bio_transient_maxcnt, 0, 127 "Maximum number of transient BIOs mappings"); 128 SYSCTL_ULONG(_kern, OID_AUTO, maxtsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxtsiz, 0, 129 "Maximum text size"); 130 SYSCTL_ULONG(_kern, OID_AUTO, dfldsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dfldsiz, 0, 131 "Initial data size limit"); 132 SYSCTL_ULONG(_kern, OID_AUTO, maxdsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxdsiz, 0, 133 "Maximum data size"); 134 SYSCTL_ULONG(_kern, OID_AUTO, dflssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dflssiz, 0, 135 "Initial stack size limit"); 136 SYSCTL_ULONG(_kern, OID_AUTO, maxssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxssiz, 0, 137 "Maximum stack size"); 138 SYSCTL_ULONG(_kern, OID_AUTO, sgrowsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &sgrowsiz, 0, 139 "Amount to grow stack on a stack fault"); 140 SYSCTL_PROC(_kern, OID_AUTO, vm_guest, CTLFLAG_RD | CTLTYPE_STRING, 141 NULL, 0, sysctl_kern_vm_guest, "A", 142 "Virtual machine guest detected?"); 143 144 /* 145 * The elements of this array are ordered based upon the values of the 146 * corresponding enum VM_GUEST members. 147 */ 148 static const char *const vm_guest_sysctl_names[] = { 149 "none", 150 "generic", 151 "xen", 152 "hv", 153 "vmware", 154 "kvm", 155 "bhyve", 156 NULL 157 }; 158 CTASSERT(nitems(vm_guest_sysctl_names) - 1 == VM_LAST); 159 160 /* 161 * Boot time overrides that are not scaled against main memory 162 */ 163 void 164 init_param1(void) 165 { 166 167 #if !defined(__mips__) && !defined(__arm64__) && !defined(__sparc64__) 168 TUNABLE_INT_FETCH("kern.kstack_pages", &kstack_pages); 169 #endif 170 hz = -1; 171 TUNABLE_INT_FETCH("kern.hz", &hz); 172 if (hz == -1) 173 hz = vm_guest > VM_GUEST_NO ? HZ_VM : HZ; 174 tick = 1000000 / hz; 175 tick_sbt = SBT_1S / hz; 176 tick_bt = sbttobt(tick_sbt); 177 178 /* 179 * Arrange for ticks to wrap 10 minutes after boot to help catch 180 * sign problems sooner. 181 */ 182 ticks = INT_MAX - (hz * 10 * 60); 183 184 #ifdef VM_SWZONE_SIZE_MAX 185 maxswzone = VM_SWZONE_SIZE_MAX; 186 #endif 187 TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone); 188 #ifdef VM_BCACHE_SIZE_MAX 189 maxbcache = VM_BCACHE_SIZE_MAX; 190 #endif 191 TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache); 192 msgbufsize = MSGBUF_SIZE; 193 TUNABLE_INT_FETCH("kern.msgbufsize", &msgbufsize); 194 195 maxtsiz = MAXTSIZ; 196 TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz); 197 dfldsiz = DFLDSIZ; 198 TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz); 199 maxdsiz = MAXDSIZ; 200 TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz); 201 dflssiz = DFLSSIZ; 202 TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz); 203 maxssiz = MAXSSIZ; 204 TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz); 205 sgrowsiz = SGROWSIZ; 206 TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz); 207 208 /* 209 * Let the administrator set {NGROUPS_MAX}, but disallow values 210 * less than NGROUPS_MAX which would violate POSIX.1-2008 or 211 * greater than INT_MAX-1 which would result in overflow. 212 */ 213 ngroups_max = NGROUPS_MAX; 214 TUNABLE_INT_FETCH("kern.ngroups", &ngroups_max); 215 if (ngroups_max < NGROUPS_MAX) 216 ngroups_max = NGROUPS_MAX; 217 218 /* 219 * Only allow to lower the maximal pid. 220 * Prevent setting up a non-bootable system if pid_max is too low. 221 */ 222 TUNABLE_INT_FETCH("kern.pid_max", &pid_max); 223 if (pid_max > PID_MAX) 224 pid_max = PID_MAX; 225 else if (pid_max < 300) 226 pid_max = 300; 227 228 TUNABLE_INT_FETCH("vfs.unmapped_buf_allowed", &unmapped_buf_allowed); 229 } 230 231 /* 232 * Boot time overrides that are scaled against main memory 233 */ 234 void 235 init_param2(long physpages) 236 { 237 238 /* Base parameters */ 239 maxusers = MAXUSERS; 240 TUNABLE_INT_FETCH("kern.maxusers", &maxusers); 241 if (maxusers == 0) { 242 maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE); 243 if (maxusers < 32) 244 maxusers = 32; 245 #ifdef VM_MAX_AUTOTUNE_MAXUSERS 246 if (maxusers > VM_MAX_AUTOTUNE_MAXUSERS) 247 maxusers = VM_MAX_AUTOTUNE_MAXUSERS; 248 #endif 249 /* 250 * Scales down the function in which maxusers grows once 251 * we hit 384. 252 */ 253 if (maxusers > 384) 254 maxusers = 384 + ((maxusers - 384) / 8); 255 } 256 257 /* 258 * The following can be overridden after boot via sysctl. Note: 259 * unless overriden, these macros are ultimately based on maxusers. 260 * Limit maxproc so that kmap entries cannot be exhausted by 261 * processes. 262 */ 263 maxproc = NPROC; 264 TUNABLE_INT_FETCH("kern.maxproc", &maxproc); 265 if (maxproc > (physpages / 12)) 266 maxproc = physpages / 12; 267 if (maxproc > pid_max) 268 maxproc = pid_max; 269 maxprocperuid = (maxproc * 9) / 10; 270 271 /* 272 * The default limit for maxfiles is 1/12 of the number of 273 * physical page but not less than 16 times maxusers. 274 * At most it can be 1/6 the number of physical pages. 275 */ 276 maxfiles = imax(MAXFILES, physpages / 8); 277 TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles); 278 if (maxfiles > (physpages / 4)) 279 maxfiles = physpages / 4; 280 maxfilesperproc = (maxfiles / 10) * 9; 281 TUNABLE_INT_FETCH("kern.maxfilesperproc", &maxfilesperproc); 282 283 /* 284 * Cannot be changed after boot. 285 */ 286 nbuf = NBUF; 287 TUNABLE_INT_FETCH("kern.nbuf", &nbuf); 288 TUNABLE_INT_FETCH("kern.bio_transient_maxcnt", &bio_transient_maxcnt); 289 290 /* 291 * Physical buffers are pre-allocated buffers (struct buf) that 292 * are used as temporary holders for I/O, such as paging I/O. 293 */ 294 TUNABLE_INT_FETCH("kern.nswbuf", &nswbuf); 295 296 /* 297 * The default for maxpipekva is min(1/64 of the kernel address space, 298 * max(1/64 of main memory, 512KB)). See sys_pipe.c for more details. 299 */ 300 maxpipekva = (physpages / 64) * PAGE_SIZE; 301 TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva); 302 if (maxpipekva < 512 * 1024) 303 maxpipekva = 512 * 1024; 304 if (maxpipekva > (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 64) 305 maxpipekva = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 306 64; 307 } 308 309 /* 310 * Sysctl stringifying handler for kern.vm_guest. 311 */ 312 static int 313 sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS) 314 { 315 return (SYSCTL_OUT_STR(req, vm_guest_sysctl_names[vm_guest])); 316 } 317