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, 141 CTLFLAG_RD | CTLTYPE_STRING | CTLFLAG_MPSAFE, NULL, 0, 142 sysctl_kern_vm_guest, "A", 143 "Virtual machine guest detected?"); 144 145 /* 146 * The elements of this array are ordered based upon the values of the 147 * corresponding enum VM_GUEST members. 148 */ 149 static const char *const vm_guest_sysctl_names[] = { 150 [VM_GUEST_NO] = "none", 151 [VM_GUEST_VM] = "generic", 152 [VM_GUEST_XEN] = "xen", 153 [VM_GUEST_HV] = "hv", 154 [VM_GUEST_VMWARE] = "vmware", 155 [VM_GUEST_KVM] = "kvm", 156 [VM_GUEST_BHYVE] = "bhyve", 157 [VM_GUEST_VBOX] = "vbox", 158 [VM_GUEST_PARALLELS] = "parallels", 159 [VM_LAST] = NULL 160 }; 161 CTASSERT(nitems(vm_guest_sysctl_names) - 1 == VM_LAST); 162 163 /* 164 * Boot time overrides that are not scaled against main memory 165 */ 166 void 167 init_param1(void) 168 { 169 170 #if !defined(__mips__) && !defined(__arm64__) 171 TUNABLE_INT_FETCH("kern.kstack_pages", &kstack_pages); 172 #endif 173 hz = -1; 174 TUNABLE_INT_FETCH("kern.hz", &hz); 175 if (hz == -1) 176 hz = vm_guest > VM_GUEST_NO ? HZ_VM : HZ; 177 tick = 1000000 / hz; 178 tick_sbt = SBT_1S / hz; 179 tick_bt = sbttobt(tick_sbt); 180 181 /* 182 * Arrange for ticks to wrap 10 minutes after boot to help catch 183 * sign problems sooner. 184 */ 185 ticks = INT_MAX - (hz * 10 * 60); 186 187 #ifdef VM_SWZONE_SIZE_MAX 188 maxswzone = VM_SWZONE_SIZE_MAX; 189 #endif 190 TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone); 191 #ifdef VM_BCACHE_SIZE_MAX 192 maxbcache = VM_BCACHE_SIZE_MAX; 193 #endif 194 TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache); 195 msgbufsize = MSGBUF_SIZE; 196 TUNABLE_INT_FETCH("kern.msgbufsize", &msgbufsize); 197 198 maxtsiz = MAXTSIZ; 199 TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz); 200 dfldsiz = DFLDSIZ; 201 TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz); 202 maxdsiz = MAXDSIZ; 203 TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz); 204 dflssiz = DFLSSIZ; 205 TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz); 206 maxssiz = MAXSSIZ; 207 TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz); 208 sgrowsiz = SGROWSIZ; 209 TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz); 210 211 /* 212 * Let the administrator set {NGROUPS_MAX}, but disallow values 213 * less than NGROUPS_MAX which would violate POSIX.1-2008 or 214 * greater than INT_MAX-1 which would result in overflow. 215 */ 216 ngroups_max = NGROUPS_MAX; 217 TUNABLE_INT_FETCH("kern.ngroups", &ngroups_max); 218 if (ngroups_max < NGROUPS_MAX) 219 ngroups_max = NGROUPS_MAX; 220 221 /* 222 * Only allow to lower the maximal pid. 223 * Prevent setting up a non-bootable system if pid_max is too low. 224 */ 225 TUNABLE_INT_FETCH("kern.pid_max", &pid_max); 226 if (pid_max > PID_MAX) 227 pid_max = PID_MAX; 228 else if (pid_max < 300) 229 pid_max = 300; 230 231 TUNABLE_INT_FETCH("vfs.unmapped_buf_allowed", &unmapped_buf_allowed); 232 } 233 234 /* 235 * Boot time overrides that are scaled against main memory 236 */ 237 void 238 init_param2(long physpages) 239 { 240 241 /* Base parameters */ 242 maxusers = MAXUSERS; 243 TUNABLE_INT_FETCH("kern.maxusers", &maxusers); 244 if (maxusers == 0) { 245 maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE); 246 if (maxusers < 32) 247 maxusers = 32; 248 #ifdef VM_MAX_AUTOTUNE_MAXUSERS 249 if (maxusers > VM_MAX_AUTOTUNE_MAXUSERS) 250 maxusers = VM_MAX_AUTOTUNE_MAXUSERS; 251 #endif 252 /* 253 * Scales down the function in which maxusers grows once 254 * we hit 384. 255 */ 256 if (maxusers > 384) 257 maxusers = 384 + ((maxusers - 384) / 8); 258 } 259 260 /* 261 * The following can be overridden after boot via sysctl. Note: 262 * unless overriden, these macros are ultimately based on maxusers. 263 * Limit maxproc so that kmap entries cannot be exhausted by 264 * processes. 265 */ 266 maxproc = NPROC; 267 TUNABLE_INT_FETCH("kern.maxproc", &maxproc); 268 if (maxproc > (physpages / 12)) 269 maxproc = physpages / 12; 270 if (maxproc > pid_max) 271 maxproc = pid_max; 272 maxprocperuid = (maxproc * 9) / 10; 273 274 /* 275 * The default limit for maxfiles is 1/12 of the number of 276 * physical page but not less than 16 times maxusers. 277 * At most it can be 1/6 the number of physical pages. 278 */ 279 maxfiles = imax(MAXFILES, physpages / 8); 280 TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles); 281 if (maxfiles > (physpages / 4)) 282 maxfiles = physpages / 4; 283 maxfilesperproc = (maxfiles / 10) * 9; 284 TUNABLE_INT_FETCH("kern.maxfilesperproc", &maxfilesperproc); 285 286 /* 287 * Cannot be changed after boot. 288 */ 289 nbuf = NBUF; 290 TUNABLE_INT_FETCH("kern.nbuf", &nbuf); 291 TUNABLE_INT_FETCH("kern.bio_transient_maxcnt", &bio_transient_maxcnt); 292 293 /* 294 * Physical buffers are pre-allocated buffers (struct buf) that 295 * are used as temporary holders for I/O, such as paging I/O. 296 */ 297 TUNABLE_INT_FETCH("kern.nswbuf", &nswbuf); 298 299 /* 300 * The default for maxpipekva is min(1/64 of the kernel address space, 301 * max(1/64 of main memory, 512KB)). See sys_pipe.c for more details. 302 */ 303 maxpipekva = (physpages / 64) * PAGE_SIZE; 304 TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva); 305 if (maxpipekva < 512 * 1024) 306 maxpipekva = 512 * 1024; 307 if (maxpipekva > (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 64) 308 maxpipekva = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 309 64; 310 } 311 312 /* 313 * Sysctl stringifying handler for kern.vm_guest. 314 */ 315 static int 316 sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS) 317 { 318 return (SYSCTL_OUT_STR(req, vm_guest_sysctl_names[vm_guest])); 319 } 320