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 # if defined(__mips__) || defined(__arm__) 67 # define HZ 100 68 # else 69 # define HZ 1000 70 # endif 71 # ifndef HZ_VM 72 # define HZ_VM 100 73 # endif 74 #else 75 # ifndef HZ_VM 76 # define HZ_VM HZ 77 # endif 78 #endif 79 #define NPROC (20 + 16 * maxusers) 80 #ifndef NBUF 81 #define NBUF 0 82 #endif 83 #ifndef MAXFILES 84 #define MAXFILES (40 + 32 * maxusers) 85 #endif 86 87 static int sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS); 88 89 int hz; /* system clock's frequency */ 90 int tick; /* usec per tick (1000000 / hz) */ 91 struct bintime tick_bt; /* bintime per tick (1s / hz) */ 92 sbintime_t tick_sbt; 93 int maxusers; /* base tunable */ 94 int maxproc; /* maximum # of processes */ 95 int maxprocperuid; /* max # of procs per user */ 96 int maxfiles; /* sys. wide open files limit */ 97 int maxfilesperproc; /* per-proc open files limit */ 98 int msgbufsize; /* size of kernel message buffer */ 99 int nbuf; /* number of bcache bufs */ 100 int bio_transient_maxcnt; 101 int ngroups_max; /* max # groups per process */ 102 int nswbuf; 103 pid_t pid_max = PID_MAX; 104 u_long maxswzone; /* max swmeta KVA storage */ 105 u_long maxbcache; /* max buffer cache KVA storage */ 106 u_long maxpipekva; /* Limit on pipe KVA */ 107 u_long maxphys; /* max raw I/O transfer size */ 108 int vm_guest = VM_GUEST_NO; /* Running as virtual machine guest? */ 109 u_long maxtsiz; /* max text size */ 110 u_long dfldsiz; /* initial data size limit */ 111 u_long maxdsiz; /* max data size */ 112 u_long dflssiz; /* initial stack size limit */ 113 u_long maxssiz; /* max stack size */ 114 u_long sgrowsiz; /* amount to grow stack */ 115 116 SYSCTL_INT(_kern, OID_AUTO, hz, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &hz, 0, 117 "Number of clock ticks per second"); 118 SYSCTL_INT(_kern, OID_AUTO, nbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nbuf, 0, 119 "Number of buffers in the buffer cache"); 120 SYSCTL_INT(_kern, OID_AUTO, nswbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nswbuf, 0, 121 "Number of swap buffers"); 122 SYSCTL_INT(_kern, OID_AUTO, msgbufsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &msgbufsize, 0, 123 "Size of the kernel message buffer"); 124 SYSCTL_LONG(_kern, OID_AUTO, maxswzone, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxswzone, 0, 125 "Maximum memory for swap metadata"); 126 SYSCTL_LONG(_kern, OID_AUTO, maxbcache, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxbcache, 0, 127 "Maximum value of vfs.maxbufspace"); 128 SYSCTL_INT(_kern, OID_AUTO, bio_transient_maxcnt, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 129 &bio_transient_maxcnt, 0, 130 "Maximum number of transient BIOs mappings"); 131 SYSCTL_ULONG(_kern, OID_AUTO, maxtsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxtsiz, 0, 132 "Maximum text size"); 133 SYSCTL_ULONG(_kern, OID_AUTO, dfldsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dfldsiz, 0, 134 "Initial data size limit"); 135 SYSCTL_ULONG(_kern, OID_AUTO, maxdsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxdsiz, 0, 136 "Maximum data size"); 137 SYSCTL_ULONG(_kern, OID_AUTO, dflssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dflssiz, 0, 138 "Initial stack size limit"); 139 SYSCTL_ULONG(_kern, OID_AUTO, maxssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxssiz, 0, 140 "Maximum stack size"); 141 SYSCTL_ULONG(_kern, OID_AUTO, sgrowsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &sgrowsiz, 0, 142 "Amount to grow stack on a stack fault"); 143 SYSCTL_PROC(_kern, OID_AUTO, vm_guest, 144 CTLFLAG_RD | CTLTYPE_STRING | CTLFLAG_MPSAFE, NULL, 0, 145 sysctl_kern_vm_guest, "A", 146 "Virtual machine guest detected?"); 147 148 /* 149 * The elements of this array are ordered based upon the values of the 150 * corresponding enum VM_GUEST members. 151 */ 152 static const char *const vm_guest_sysctl_names[] = { 153 [VM_GUEST_NO] = "none", 154 [VM_GUEST_VM] = "generic", 155 [VM_GUEST_XEN] = "xen", 156 [VM_GUEST_HV] = "hv", 157 [VM_GUEST_VMWARE] = "vmware", 158 [VM_GUEST_KVM] = "kvm", 159 [VM_GUEST_BHYVE] = "bhyve", 160 [VM_GUEST_VBOX] = "vbox", 161 [VM_GUEST_PARALLELS] = "parallels", 162 [VM_LAST] = NULL 163 }; 164 CTASSERT(nitems(vm_guest_sysctl_names) - 1 == VM_LAST); 165 166 /* 167 * Boot time overrides that are not scaled against main memory 168 */ 169 void 170 init_param1(void) 171 { 172 173 #if !defined(__mips__) && !defined(__arm64__) 174 TUNABLE_INT_FETCH("kern.kstack_pages", &kstack_pages); 175 #endif 176 hz = -1; 177 TUNABLE_INT_FETCH("kern.hz", &hz); 178 if (hz == -1) 179 hz = vm_guest > VM_GUEST_NO ? HZ_VM : HZ; 180 tick = 1000000 / hz; 181 tick_sbt = SBT_1S / hz; 182 tick_bt = sbttobt(tick_sbt); 183 184 /* 185 * Arrange for ticks to wrap 10 minutes after boot to help catch 186 * sign problems sooner. 187 */ 188 ticks = INT_MAX - (hz * 10 * 60); 189 190 vn_lock_pair_pause_max = hz / 100; 191 if (vn_lock_pair_pause_max == 0) 192 vn_lock_pair_pause_max = 1; 193 194 #ifdef VM_SWZONE_SIZE_MAX 195 maxswzone = VM_SWZONE_SIZE_MAX; 196 #endif 197 TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone); 198 #ifdef VM_BCACHE_SIZE_MAX 199 maxbcache = VM_BCACHE_SIZE_MAX; 200 #endif 201 TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache); 202 msgbufsize = MSGBUF_SIZE; 203 TUNABLE_INT_FETCH("kern.msgbufsize", &msgbufsize); 204 205 maxtsiz = MAXTSIZ; 206 TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz); 207 dfldsiz = DFLDSIZ; 208 TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz); 209 maxdsiz = MAXDSIZ; 210 TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz); 211 dflssiz = DFLSSIZ; 212 TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz); 213 maxssiz = MAXSSIZ; 214 TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz); 215 sgrowsiz = SGROWSIZ; 216 TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz); 217 218 /* 219 * Let the administrator set {NGROUPS_MAX}, but disallow values 220 * less than NGROUPS_MAX which would violate POSIX.1-2008 or 221 * greater than INT_MAX-1 which would result in overflow. 222 */ 223 ngroups_max = NGROUPS_MAX; 224 TUNABLE_INT_FETCH("kern.ngroups", &ngroups_max); 225 if (ngroups_max < NGROUPS_MAX) 226 ngroups_max = NGROUPS_MAX; 227 228 /* 229 * Only allow to lower the maximal pid. 230 * Prevent setting up a non-bootable system if pid_max is too low. 231 */ 232 TUNABLE_INT_FETCH("kern.pid_max", &pid_max); 233 if (pid_max > PID_MAX) 234 pid_max = PID_MAX; 235 else if (pid_max < 300) 236 pid_max = 300; 237 238 TUNABLE_INT_FETCH("vfs.unmapped_buf_allowed", &unmapped_buf_allowed); 239 } 240 241 /* 242 * Boot time overrides that are scaled against main memory 243 */ 244 void 245 init_param2(long physpages) 246 { 247 248 /* Base parameters */ 249 maxusers = MAXUSERS; 250 TUNABLE_INT_FETCH("kern.maxusers", &maxusers); 251 if (maxusers == 0) { 252 maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE); 253 if (maxusers < 32) 254 maxusers = 32; 255 #ifdef VM_MAX_AUTOTUNE_MAXUSERS 256 if (maxusers > VM_MAX_AUTOTUNE_MAXUSERS) 257 maxusers = VM_MAX_AUTOTUNE_MAXUSERS; 258 #endif 259 /* 260 * Scales down the function in which maxusers grows once 261 * we hit 384. 262 */ 263 if (maxusers > 384) 264 maxusers = 384 + ((maxusers - 384) / 8); 265 } 266 267 /* 268 * The following can be overridden after boot via sysctl. Note: 269 * unless overriden, these macros are ultimately based on maxusers. 270 * Limit maxproc so that kmap entries cannot be exhausted by 271 * processes. 272 */ 273 maxproc = NPROC; 274 TUNABLE_INT_FETCH("kern.maxproc", &maxproc); 275 if (maxproc > (physpages / 12)) 276 maxproc = physpages / 12; 277 if (maxproc > pid_max) 278 maxproc = pid_max; 279 maxprocperuid = (maxproc * 9) / 10; 280 281 /* 282 * The default limit for maxfiles is 1/12 of the number of 283 * physical page but not less than 16 times maxusers. 284 * At most it can be 1/6 the number of physical pages. 285 */ 286 maxfiles = imax(MAXFILES, physpages / 8); 287 TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles); 288 if (maxfiles > (physpages / 4)) 289 maxfiles = physpages / 4; 290 maxfilesperproc = (maxfiles / 10) * 9; 291 TUNABLE_INT_FETCH("kern.maxfilesperproc", &maxfilesperproc); 292 293 /* 294 * Cannot be changed after boot. 295 */ 296 nbuf = NBUF; 297 TUNABLE_INT_FETCH("kern.nbuf", &nbuf); 298 TUNABLE_INT_FETCH("kern.bio_transient_maxcnt", &bio_transient_maxcnt); 299 maxphys = MAXPHYS; 300 TUNABLE_ULONG_FETCH("kern.maxphys", &maxphys); 301 if (maxphys == 0) { 302 maxphys = MAXPHYS; 303 } else if (__bitcountl(maxphys) != 1) { /* power of two */ 304 if (flsl(maxphys) == NBBY * sizeof(maxphys)) 305 maxphys = MAXPHYS; 306 else 307 maxphys = 1UL << flsl(maxphys); 308 } 309 if (maxphys < PAGE_SIZE) 310 maxphys = MAXPHYS; 311 312 /* 313 * Physical buffers are pre-allocated buffers (struct buf) that 314 * are used as temporary holders for I/O, such as paging I/O. 315 */ 316 TUNABLE_INT_FETCH("kern.nswbuf", &nswbuf); 317 318 /* 319 * The default for maxpipekva is min(1/64 of the kernel address space, 320 * max(1/64 of main memory, 512KB)). See sys_pipe.c for more details. 321 */ 322 maxpipekva = ptoa(physpages / 64); 323 TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva); 324 if (maxpipekva < 512 * 1024) 325 maxpipekva = 512 * 1024; 326 if (maxpipekva > (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 64) 327 maxpipekva = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 328 64; 329 } 330 331 /* 332 * Sysctl stringifying handler for kern.vm_guest. 333 */ 334 static int 335 sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS) 336 { 337 return (SYSCTL_OUT_STR(req, vm_guest_sysctl_names[vm_guest])); 338 } 339