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/kernel.h> 49 #include <sys/limits.h> 50 #include <sys/msgbuf.h> 51 #include <sys/sysctl.h> 52 #include <sys/proc.h> 53 54 #include <vm/vm.h> 55 #include <vm/vm_param.h> 56 #include <vm/pmap.h> 57 58 /* 59 * System parameter formulae. 60 */ 61 62 #ifndef HZ 63 # if defined(__mips__) || defined(__arm__) 64 # define HZ 100 65 # else 66 # define HZ 1000 67 # endif 68 # ifndef HZ_VM 69 # define HZ_VM 100 70 # endif 71 #else 72 # ifndef HZ_VM 73 # define HZ_VM HZ 74 # endif 75 #endif 76 #define NPROC (20 + 16 * maxusers) 77 #ifndef NBUF 78 #define NBUF 0 79 #endif 80 #ifndef MAXFILES 81 #define MAXFILES (40 + 32 * maxusers) 82 #endif 83 84 static int sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS); 85 86 int hz; /* system clock's frequency */ 87 int tick; /* usec per tick (1000000 / hz) */ 88 struct bintime tick_bt; /* bintime per tick (1s / hz) */ 89 sbintime_t tick_sbt; 90 int maxusers; /* base tunable */ 91 int maxproc; /* maximum # of processes */ 92 int maxprocperuid; /* max # of procs per user */ 93 int maxfiles; /* sys. wide open files limit */ 94 int maxfilesperproc; /* per-proc open files limit */ 95 int msgbufsize; /* size of kernel message buffer */ 96 int nbuf; 97 int bio_transient_maxcnt; 98 int ngroups_max; /* max # groups per process */ 99 int nswbuf; 100 pid_t pid_max = PID_MAX; 101 long maxswzone; /* max swmeta KVA storage */ 102 long maxbcache; /* max buffer cache KVA storage */ 103 long maxpipekva; /* Limit on pipe KVA */ 104 int vm_guest = VM_GUEST_NO; /* Running as virtual machine guest? */ 105 u_long maxtsiz; /* max text size */ 106 u_long dfldsiz; /* initial data size limit */ 107 u_long maxdsiz; /* max data size */ 108 u_long dflssiz; /* initial stack size limit */ 109 u_long maxssiz; /* max stack size */ 110 u_long sgrowsiz; /* amount to grow stack */ 111 112 SYSCTL_INT(_kern, OID_AUTO, hz, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &hz, 0, 113 "Number of clock ticks per second"); 114 SYSCTL_INT(_kern, OID_AUTO, nbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nbuf, 0, 115 "Number of buffers in the buffer cache"); 116 SYSCTL_INT(_kern, OID_AUTO, nswbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nswbuf, 0, 117 "Number of swap buffers"); 118 SYSCTL_INT(_kern, OID_AUTO, msgbufsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &msgbufsize, 0, 119 "Size of the kernel message buffer"); 120 SYSCTL_LONG(_kern, OID_AUTO, maxswzone, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxswzone, 0, 121 "Maximum memory for swap metadata"); 122 SYSCTL_LONG(_kern, OID_AUTO, maxbcache, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxbcache, 0, 123 "Maximum value of vfs.maxbufspace"); 124 SYSCTL_INT(_kern, OID_AUTO, bio_transient_maxcnt, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 125 &bio_transient_maxcnt, 0, 126 "Maximum number of transient BIOs mappings"); 127 SYSCTL_ULONG(_kern, OID_AUTO, maxtsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxtsiz, 0, 128 "Maximum text size"); 129 SYSCTL_ULONG(_kern, OID_AUTO, dfldsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dfldsiz, 0, 130 "Initial data size limit"); 131 SYSCTL_ULONG(_kern, OID_AUTO, maxdsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxdsiz, 0, 132 "Maximum data size"); 133 SYSCTL_ULONG(_kern, OID_AUTO, dflssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dflssiz, 0, 134 "Initial stack size limit"); 135 SYSCTL_ULONG(_kern, OID_AUTO, maxssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxssiz, 0, 136 "Maximum stack size"); 137 SYSCTL_ULONG(_kern, OID_AUTO, sgrowsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &sgrowsiz, 0, 138 "Amount to grow stack on a stack fault"); 139 SYSCTL_PROC(_kern, OID_AUTO, vm_guest, CTLFLAG_RD | CTLTYPE_STRING, 140 NULL, 0, sysctl_kern_vm_guest, "A", 141 "Virtual machine guest detected?"); 142 143 /* 144 * The elements of this array are ordered based upon the values of the 145 * corresponding enum VM_GUEST members. 146 */ 147 static const char *const vm_guest_sysctl_names[] = { 148 "none", 149 "generic", 150 "xen", 151 "hv", 152 "vmware", 153 "kvm", 154 "bhyve", 155 NULL 156 }; 157 CTASSERT(nitems(vm_guest_sysctl_names) - 1 == VM_LAST); 158 159 /* 160 * Boot time overrides that are not scaled against main memory 161 */ 162 void 163 init_param1(void) 164 { 165 166 #if !defined(__mips__) && !defined(__arm64__) && !defined(__sparc64__) 167 TUNABLE_INT_FETCH("kern.kstack_pages", &kstack_pages); 168 #endif 169 hz = -1; 170 TUNABLE_INT_FETCH("kern.hz", &hz); 171 if (hz == -1) 172 hz = vm_guest > VM_GUEST_NO ? HZ_VM : HZ; 173 tick = 1000000 / hz; 174 tick_sbt = SBT_1S / hz; 175 tick_bt = sbttobt(tick_sbt); 176 177 /* 178 * Arrange for ticks to wrap 10 minutes after boot to help catch 179 * sign problems sooner. 180 */ 181 ticks = INT_MAX - (hz * 10 * 60); 182 183 #ifdef VM_SWZONE_SIZE_MAX 184 maxswzone = VM_SWZONE_SIZE_MAX; 185 #endif 186 TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone); 187 #ifdef VM_BCACHE_SIZE_MAX 188 maxbcache = VM_BCACHE_SIZE_MAX; 189 #endif 190 TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache); 191 msgbufsize = MSGBUF_SIZE; 192 TUNABLE_INT_FETCH("kern.msgbufsize", &msgbufsize); 193 194 maxtsiz = MAXTSIZ; 195 TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz); 196 dfldsiz = DFLDSIZ; 197 TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz); 198 maxdsiz = MAXDSIZ; 199 TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz); 200 dflssiz = DFLSSIZ; 201 TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz); 202 maxssiz = MAXSSIZ; 203 TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz); 204 sgrowsiz = SGROWSIZ; 205 TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz); 206 207 /* 208 * Let the administrator set {NGROUPS_MAX}, but disallow values 209 * less than NGROUPS_MAX which would violate POSIX.1-2008 or 210 * greater than INT_MAX-1 which would result in overflow. 211 */ 212 ngroups_max = NGROUPS_MAX; 213 TUNABLE_INT_FETCH("kern.ngroups", &ngroups_max); 214 if (ngroups_max < NGROUPS_MAX) 215 ngroups_max = NGROUPS_MAX; 216 217 /* 218 * Only allow to lower the maximal pid. 219 * Prevent setting up a non-bootable system if pid_max is too low. 220 */ 221 TUNABLE_INT_FETCH("kern.pid_max", &pid_max); 222 if (pid_max > PID_MAX) 223 pid_max = PID_MAX; 224 else if (pid_max < 300) 225 pid_max = 300; 226 227 TUNABLE_INT_FETCH("vfs.unmapped_buf_allowed", &unmapped_buf_allowed); 228 } 229 230 /* 231 * Boot time overrides that are scaled against main memory 232 */ 233 void 234 init_param2(long physpages) 235 { 236 237 /* Base parameters */ 238 maxusers = MAXUSERS; 239 TUNABLE_INT_FETCH("kern.maxusers", &maxusers); 240 if (maxusers == 0) { 241 maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE); 242 if (maxusers < 32) 243 maxusers = 32; 244 #ifdef VM_MAX_AUTOTUNE_MAXUSERS 245 if (maxusers > VM_MAX_AUTOTUNE_MAXUSERS) 246 maxusers = VM_MAX_AUTOTUNE_MAXUSERS; 247 #endif 248 /* 249 * Scales down the function in which maxusers grows once 250 * we hit 384. 251 */ 252 if (maxusers > 384) 253 maxusers = 384 + ((maxusers - 384) / 8); 254 } 255 256 /* 257 * The following can be overridden after boot via sysctl. Note: 258 * unless overriden, these macros are ultimately based on maxusers. 259 * Limit maxproc so that kmap entries cannot be exhausted by 260 * processes. 261 */ 262 maxproc = NPROC; 263 TUNABLE_INT_FETCH("kern.maxproc", &maxproc); 264 if (maxproc > (physpages / 12)) 265 maxproc = physpages / 12; 266 if (maxproc > pid_max) 267 maxproc = pid_max; 268 maxprocperuid = (maxproc * 9) / 10; 269 270 /* 271 * The default limit for maxfiles is 1/12 of the number of 272 * physical page but not less than 16 times maxusers. 273 * At most it can be 1/6 the number of physical pages. 274 */ 275 maxfiles = imax(MAXFILES, physpages / 8); 276 TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles); 277 if (maxfiles > (physpages / 4)) 278 maxfiles = physpages / 4; 279 maxfilesperproc = (maxfiles / 10) * 9; 280 TUNABLE_INT_FETCH("kern.maxfilesperproc", &maxfilesperproc); 281 282 /* 283 * Cannot be changed after boot. 284 */ 285 nbuf = NBUF; 286 TUNABLE_INT_FETCH("kern.nbuf", &nbuf); 287 TUNABLE_INT_FETCH("kern.bio_transient_maxcnt", &bio_transient_maxcnt); 288 289 /* 290 * The default for maxpipekva is min(1/64 of the kernel address space, 291 * max(1/64 of main memory, 512KB)). See sys_pipe.c for more details. 292 */ 293 maxpipekva = (physpages / 64) * PAGE_SIZE; 294 TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva); 295 if (maxpipekva < 512 * 1024) 296 maxpipekva = 512 * 1024; 297 if (maxpipekva > (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 64) 298 maxpipekva = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 299 64; 300 } 301 302 /* 303 * Sysctl stringifying handler for kern.vm_guest. 304 */ 305 static int 306 sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS) 307 { 308 return (SYSCTL_OUT_STR(req, vm_guest_sysctl_names[vm_guest])); 309 } 310