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_maxphys.h" 45 #include "opt_maxusers.h" 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/buf.h> 50 #include <sys/kernel.h> 51 #include <sys/limits.h> 52 #include <sys/msgbuf.h> 53 #include <sys/sysctl.h> 54 #include <sys/proc.h> 55 #include <sys/vnode.h> 56 57 #include <vm/vm.h> 58 #include <vm/vm_param.h> 59 #include <vm/pmap.h> 60 61 /* 62 * System parameter formulae. 63 */ 64 65 #ifndef HZ 66 # define HZ 1000 67 # ifndef HZ_VM 68 # define HZ_VM 100 69 # endif 70 #else 71 # ifndef HZ_VM 72 # define HZ_VM HZ 73 # endif 74 #endif 75 #define NPROC (20 + 16 * maxusers) 76 #ifndef NBUF 77 #define NBUF 0 78 #endif 79 #ifndef MAXFILES 80 #define MAXFILES (40 + 32 * maxusers) 81 #endif 82 83 static int sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS); 84 85 int hz; /* system clock's frequency */ 86 int tick; /* usec per tick (1000000 / hz) */ 87 time_t tick_seconds_max; /* max hz * seconds an integer can hold */ 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; /* number of bcache bufs */ 97 int bio_transient_maxcnt; 98 int ngroups_max; /* max # groups per process */ 99 int nswbuf; 100 pid_t pid_max = PID_MAX; 101 u_long maxswzone; /* max swmeta KVA storage */ 102 u_long maxbcache; /* max buffer cache KVA storage */ 103 u_long maxpipekva; /* Limit on pipe KVA */ 104 u_long maxphys; /* max raw I/O transfer size */ 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, hz_max, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, HZ_MAXIMUM, 116 "Maximum hz value supported"); 117 SYSCTL_INT(_kern, OID_AUTO, hz_min, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, HZ_MINIMUM, 118 "Minimum hz value supported"); 119 SYSCTL_INT(_kern, OID_AUTO, nbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nbuf, 0, 120 "Number of buffers in the buffer cache"); 121 SYSCTL_INT(_kern, OID_AUTO, nswbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nswbuf, 0, 122 "Number of swap buffers"); 123 SYSCTL_INT(_kern, OID_AUTO, msgbufsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &msgbufsize, 0, 124 "Size of the kernel message buffer"); 125 SYSCTL_LONG(_kern, OID_AUTO, maxswzone, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxswzone, 0, 126 "Maximum memory for swap metadata"); 127 SYSCTL_LONG(_kern, OID_AUTO, maxbcache, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxbcache, 0, 128 "Maximum value of vfs.maxbufspace"); 129 SYSCTL_INT(_kern, OID_AUTO, bio_transient_maxcnt, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 130 &bio_transient_maxcnt, 0, 131 "Maximum number of transient BIOs mappings"); 132 SYSCTL_ULONG(_kern, OID_AUTO, maxtsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxtsiz, 0, 133 "Maximum text size"); 134 SYSCTL_ULONG(_kern, OID_AUTO, dfldsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dfldsiz, 0, 135 "Initial data size limit"); 136 SYSCTL_ULONG(_kern, OID_AUTO, maxdsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxdsiz, 0, 137 "Maximum data size"); 138 SYSCTL_ULONG(_kern, OID_AUTO, dflssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dflssiz, 0, 139 "Initial stack size limit"); 140 SYSCTL_ULONG(_kern, OID_AUTO, maxssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxssiz, 0, 141 "Maximum stack size"); 142 SYSCTL_ULONG(_kern, OID_AUTO, sgrowsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &sgrowsiz, 0, 143 "Amount to grow stack on a stack fault"); 144 SYSCTL_PROC(_kern, OID_AUTO, vm_guest, 145 CTLFLAG_RD | CTLTYPE_STRING | CTLFLAG_MPSAFE, NULL, 0, 146 sysctl_kern_vm_guest, "A", 147 "Virtual machine guest detected?"); 148 149 /* 150 * The elements of this array are ordered based upon the values of the 151 * corresponding enum VM_GUEST members. 152 */ 153 static const char *const vm_guest_sysctl_names[] = { 154 [VM_GUEST_NO] = "none", 155 [VM_GUEST_VM] = "generic", 156 [VM_GUEST_XEN] = "xen", 157 [VM_GUEST_HV] = "hv", 158 [VM_GUEST_VMWARE] = "vmware", 159 [VM_GUEST_KVM] = "kvm", 160 [VM_GUEST_BHYVE] = "bhyve", 161 [VM_GUEST_VBOX] = "vbox", 162 [VM_GUEST_PARALLELS] = "parallels", 163 [VM_LAST] = NULL 164 }; 165 CTASSERT(nitems(vm_guest_sysctl_names) - 1 == VM_LAST); 166 167 /* 168 * Boot time overrides that are not scaled against main memory 169 */ 170 void 171 init_param1(void) 172 { 173 174 #if !defined(__arm64__) 175 TUNABLE_INT_FETCH("kern.kstack_pages", &kstack_pages); 176 #endif 177 hz = -1; 178 TUNABLE_INT_FETCH("kern.hz", &hz); 179 if (hz == -1) 180 hz = vm_guest > VM_GUEST_NO ? HZ_VM : HZ; 181 182 /* range check the "hz" value */ 183 if (__predict_false(hz < HZ_MINIMUM)) 184 hz = HZ_MINIMUM; 185 else if (__predict_false(hz > HZ_MAXIMUM)) 186 hz = HZ_MAXIMUM; 187 188 tick = 1000000 / hz; 189 tick_sbt = SBT_1S / hz; 190 tick_bt = sbttobt(tick_sbt); 191 tick_seconds_max = INT_MAX / hz; 192 193 /* 194 * Arrange for ticks to wrap 10 minutes after boot to help catch 195 * sign problems sooner. 196 */ 197 ticks = INT_MAX - (hz * 10 * 60); 198 199 vn_lock_pair_pause_max = hz / 100; 200 if (vn_lock_pair_pause_max == 0) 201 vn_lock_pair_pause_max = 1; 202 203 #ifdef VM_SWZONE_SIZE_MAX 204 maxswzone = VM_SWZONE_SIZE_MAX; 205 #endif 206 TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone); 207 #ifdef VM_BCACHE_SIZE_MAX 208 maxbcache = VM_BCACHE_SIZE_MAX; 209 #endif 210 TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache); 211 msgbufsize = MSGBUF_SIZE; 212 TUNABLE_INT_FETCH("kern.msgbufsize", &msgbufsize); 213 214 maxtsiz = MAXTSIZ; 215 TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz); 216 dfldsiz = DFLDSIZ; 217 TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz); 218 maxdsiz = MAXDSIZ; 219 TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz); 220 dflssiz = DFLSSIZ; 221 TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz); 222 maxssiz = MAXSSIZ; 223 TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz); 224 sgrowsiz = SGROWSIZ; 225 TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz); 226 227 /* 228 * Let the administrator set {NGROUPS_MAX}, but disallow values 229 * less than NGROUPS_MAX which would violate POSIX.1-2008 or 230 * greater than INT_MAX-1 which would result in overflow. 231 */ 232 ngroups_max = NGROUPS_MAX; 233 TUNABLE_INT_FETCH("kern.ngroups", &ngroups_max); 234 if (ngroups_max < NGROUPS_MAX) 235 ngroups_max = NGROUPS_MAX; 236 237 /* 238 * Only allow to lower the maximal pid. 239 * Prevent setting up a non-bootable system if pid_max is too low. 240 */ 241 TUNABLE_INT_FETCH("kern.pid_max", &pid_max); 242 if (pid_max > PID_MAX) 243 pid_max = PID_MAX; 244 else if (pid_max < 300) 245 pid_max = 300; 246 247 TUNABLE_INT_FETCH("vfs.unmapped_buf_allowed", &unmapped_buf_allowed); 248 } 249 250 /* 251 * Boot time overrides that are scaled against main memory 252 */ 253 void 254 init_param2(long physpages) 255 { 256 257 /* Base parameters */ 258 maxusers = MAXUSERS; 259 TUNABLE_INT_FETCH("kern.maxusers", &maxusers); 260 if (maxusers == 0) { 261 maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE); 262 if (maxusers < 32) 263 maxusers = 32; 264 #ifdef VM_MAX_AUTOTUNE_MAXUSERS 265 if (maxusers > VM_MAX_AUTOTUNE_MAXUSERS) 266 maxusers = VM_MAX_AUTOTUNE_MAXUSERS; 267 #endif 268 /* 269 * Scales down the function in which maxusers grows once 270 * we hit 384. 271 */ 272 if (maxusers > 384) 273 maxusers = 384 + ((maxusers - 384) / 8); 274 } 275 276 /* 277 * The following can be overridden after boot via sysctl. Note: 278 * unless overridden, these macros are ultimately based on maxusers. 279 * Limit maxproc so that kmap entries cannot be exhausted by 280 * processes. 281 */ 282 maxproc = NPROC; 283 TUNABLE_INT_FETCH("kern.maxproc", &maxproc); 284 if (maxproc > (physpages / 12)) 285 maxproc = physpages / 12; 286 if (maxproc > pid_max) 287 maxproc = pid_max; 288 maxprocperuid = (maxproc * 9) / 10; 289 290 /* 291 * The default limit for maxfiles is 1/12 of the number of 292 * physical page but not less than 16 times maxusers. 293 * At most it can be 1/6 the number of physical pages. 294 */ 295 maxfiles = imax(MAXFILES, physpages / 8); 296 TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles); 297 if (maxfiles > (physpages / 4)) 298 maxfiles = physpages / 4; 299 maxfilesperproc = (maxfiles / 10) * 9; 300 TUNABLE_INT_FETCH("kern.maxfilesperproc", &maxfilesperproc); 301 302 /* 303 * Cannot be changed after boot. 304 */ 305 nbuf = NBUF; 306 TUNABLE_INT_FETCH("kern.nbuf", &nbuf); 307 TUNABLE_INT_FETCH("kern.bio_transient_maxcnt", &bio_transient_maxcnt); 308 maxphys = MAXPHYS; 309 TUNABLE_ULONG_FETCH("kern.maxphys", &maxphys); 310 if (maxphys == 0) { 311 maxphys = MAXPHYS; 312 } else if (__bitcountl(maxphys) != 1) { /* power of two */ 313 if (flsl(maxphys) == NBBY * sizeof(maxphys)) 314 maxphys = MAXPHYS; 315 else 316 maxphys = 1UL << flsl(maxphys); 317 } 318 if (maxphys < PAGE_SIZE) 319 maxphys = MAXPHYS; 320 321 /* 322 * Physical buffers are pre-allocated buffers (struct buf) that 323 * are used as temporary holders for I/O, such as paging I/O. 324 */ 325 TUNABLE_INT_FETCH("kern.nswbuf", &nswbuf); 326 327 /* 328 * The default for maxpipekva is min(1/64 of the kernel address space, 329 * max(1/64 of main memory, 512KB)). See sys_pipe.c for more details. 330 */ 331 maxpipekva = ptoa(physpages / 64); 332 TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva); 333 if (maxpipekva < 512 * 1024) 334 maxpipekva = 512 * 1024; 335 if (maxpipekva > (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 64) 336 maxpipekva = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 337 64; 338 } 339 340 /* 341 * Sysctl stringifying handler for kern.vm_guest. 342 */ 343 static int 344 sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS) 345 { 346 return (SYSCTL_OUT_STR(req, vm_guest_sysctl_names[vm_guest])); 347 } 348