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 #include "opt_param.h" 41 #include "opt_msgbuf.h" 42 #include "opt_maxphys.h" 43 #include "opt_maxusers.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/buf.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 #include <sys/vnode.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 # define HZ 1000 65 # ifndef HZ_VM 66 # define HZ_VM 100 67 # endif 68 #else 69 # ifndef HZ_VM 70 # define HZ_VM HZ 71 # endif 72 #endif 73 #define NPROC (20 + 16 * maxusers) 74 #ifndef NBUF 75 #define NBUF 0 76 #endif 77 #ifndef MAXFILES 78 #define MAXFILES (40 + 32 * maxusers) 79 #endif 80 81 static int sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS); 82 83 int hz; /* system clock's frequency */ 84 int tick; /* usec per tick (1000000 / hz) */ 85 time_t tick_seconds_max; /* max hz * seconds an integer can hold */ 86 struct bintime tick_bt; /* bintime per tick (1s / hz) */ 87 sbintime_t tick_sbt; 88 int maxusers; /* base tunable */ 89 int maxproc; /* maximum # of processes */ 90 int maxprocperuid; /* max # of procs per user */ 91 int maxfiles; /* sys. wide open files limit */ 92 int maxfilesperproc; /* per-proc open files limit */ 93 int msgbufsize; /* size of kernel message buffer */ 94 int nbuf; /* number of bcache bufs */ 95 int bio_transient_maxcnt; 96 int ngroups_max; /* max # groups per process */ 97 int nswbuf; 98 pid_t pid_max = PID_MAX; 99 u_long maxswzone; /* max swmeta KVA storage */ 100 u_long maxbcache; /* max buffer cache KVA storage */ 101 u_long maxpipekva; /* Limit on pipe KVA */ 102 u_long maxphys; /* max raw I/O transfer size */ 103 int vm_guest = VM_GUEST_NO; /* Running as virtual machine guest? */ 104 u_long maxtsiz; /* max text size */ 105 u_long dfldsiz; /* initial data size limit */ 106 u_long maxdsiz; /* max data size */ 107 u_long dflssiz; /* initial stack size limit */ 108 u_long maxssiz; /* max stack size */ 109 u_long sgrowsiz; /* amount to grow stack */ 110 111 SYSCTL_INT(_kern, OID_AUTO, hz, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &hz, 0, 112 "Number of clock ticks per second"); 113 SYSCTL_INT(_kern, OID_AUTO, hz_max, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, HZ_MAXIMUM, 114 "Maximum hz value supported"); 115 SYSCTL_INT(_kern, OID_AUTO, hz_min, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, HZ_MINIMUM, 116 "Minimum hz value supported"); 117 SYSCTL_INT(_kern, OID_AUTO, nbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nbuf, 0, 118 "Number of buffers in the buffer cache"); 119 SYSCTL_INT(_kern, OID_AUTO, nswbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nswbuf, 0, 120 "Number of swap buffers"); 121 SYSCTL_INT(_kern, OID_AUTO, msgbufsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &msgbufsize, 0, 122 "Size of the kernel message buffer"); 123 SYSCTL_LONG(_kern, OID_AUTO, maxswzone, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxswzone, 0, 124 "Maximum memory for swap metadata"); 125 SYSCTL_LONG(_kern, OID_AUTO, maxbcache, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxbcache, 0, 126 "Maximum value of vfs.maxbufspace"); 127 SYSCTL_INT(_kern, OID_AUTO, bio_transient_maxcnt, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 128 &bio_transient_maxcnt, 0, 129 "Maximum number of transient BIOs mappings"); 130 SYSCTL_ULONG(_kern, OID_AUTO, maxtsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxtsiz, 0, 131 "Maximum text size"); 132 SYSCTL_ULONG(_kern, OID_AUTO, dfldsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dfldsiz, 0, 133 "Initial data size limit"); 134 SYSCTL_ULONG(_kern, OID_AUTO, maxdsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxdsiz, 0, 135 "Maximum data size"); 136 SYSCTL_ULONG(_kern, OID_AUTO, dflssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dflssiz, 0, 137 "Initial stack size limit"); 138 SYSCTL_ULONG(_kern, OID_AUTO, maxssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxssiz, 0, 139 "Maximum stack size"); 140 SYSCTL_ULONG(_kern, OID_AUTO, sgrowsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &sgrowsiz, 0, 141 "Amount to grow stack on a stack fault"); 142 SYSCTL_PROC(_kern, OID_AUTO, vm_guest, 143 CTLFLAG_RD | CTLTYPE_STRING | CTLFLAG_MPSAFE, NULL, 0, 144 sysctl_kern_vm_guest, "A", 145 "Virtual machine guest detected?"); 146 147 /* 148 * The elements of this array are ordered based upon the values of the 149 * corresponding enum VM_GUEST members. 150 */ 151 static const char *const vm_guest_sysctl_names[] = { 152 [VM_GUEST_NO] = "none", 153 [VM_GUEST_VM] = "generic", 154 [VM_GUEST_XEN] = "xen", 155 [VM_GUEST_HV] = "hv", 156 [VM_GUEST_VMWARE] = "vmware", 157 [VM_GUEST_KVM] = "kvm", 158 [VM_GUEST_BHYVE] = "bhyve", 159 [VM_GUEST_VBOX] = "vbox", 160 [VM_GUEST_PARALLELS] = "parallels", 161 [VM_LAST] = NULL 162 }; 163 CTASSERT(nitems(vm_guest_sysctl_names) - 1 == VM_LAST); 164 165 /* 166 * Boot time overrides that are not scaled against main memory 167 */ 168 void 169 init_param1(void) 170 { 171 172 TSENTER(); 173 174 /* 175 * arm64 and riscv currently hard-code the thread0 kstack size 176 * to KSTACK_PAGES, ignoring the tunable. 177 */ 178 TUNABLE_INT_FETCH("kern.kstack_pages", &kstack_pages); 179 180 hz = -1; 181 TUNABLE_INT_FETCH("kern.hz", &hz); 182 if (hz == -1) 183 hz = vm_guest > VM_GUEST_NO ? HZ_VM : HZ; 184 185 /* range check the "hz" value */ 186 if (__predict_false(hz < HZ_MINIMUM)) 187 hz = HZ_MINIMUM; 188 else if (__predict_false(hz > HZ_MAXIMUM)) 189 hz = HZ_MAXIMUM; 190 191 tick = 1000000 / hz; 192 tick_sbt = SBT_1S / hz; 193 tick_bt = sbttobt(tick_sbt); 194 tick_seconds_max = INT_MAX / hz; 195 196 /* 197 * Arrange for ticks to wrap 10 minutes after boot to help catch 198 * sign problems sooner. 199 */ 200 ticks = INT_MAX - (hz * 10 * 60); 201 202 vn_lock_pair_pause_max = hz / 100; 203 if (vn_lock_pair_pause_max == 0) 204 vn_lock_pair_pause_max = 1; 205 206 #ifdef VM_SWZONE_SIZE_MAX 207 maxswzone = VM_SWZONE_SIZE_MAX; 208 #endif 209 TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone); 210 #ifdef VM_BCACHE_SIZE_MAX 211 maxbcache = VM_BCACHE_SIZE_MAX; 212 #endif 213 TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache); 214 msgbufsize = MSGBUF_SIZE; 215 TUNABLE_INT_FETCH("kern.msgbufsize", &msgbufsize); 216 217 maxtsiz = MAXTSIZ; 218 TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz); 219 dfldsiz = DFLDSIZ; 220 TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz); 221 maxdsiz = MAXDSIZ; 222 TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz); 223 dflssiz = DFLSSIZ; 224 TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz); 225 maxssiz = MAXSSIZ; 226 TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz); 227 sgrowsiz = SGROWSIZ; 228 TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz); 229 230 /* 231 * Let the administrator set {NGROUPS_MAX}, but disallow values 232 * less than NGROUPS_MAX which would violate POSIX.1-2008 or 233 * greater than INT_MAX-1 which would result in overflow. 234 */ 235 ngroups_max = NGROUPS_MAX; 236 TUNABLE_INT_FETCH("kern.ngroups", &ngroups_max); 237 if (ngroups_max < NGROUPS_MAX) 238 ngroups_max = NGROUPS_MAX; 239 240 /* 241 * Only allow to lower the maximal pid. 242 * Prevent setting up a non-bootable system if pid_max is too low. 243 */ 244 TUNABLE_INT_FETCH("kern.pid_max", &pid_max); 245 if (pid_max > PID_MAX) 246 pid_max = PID_MAX; 247 else if (pid_max < 300) 248 pid_max = 300; 249 250 TUNABLE_INT_FETCH("vfs.unmapped_buf_allowed", &unmapped_buf_allowed); 251 TSEXIT(); 252 } 253 254 /* 255 * Boot time overrides that are scaled against main memory 256 */ 257 void 258 init_param2(long physpages) 259 { 260 261 TSENTER(); 262 /* Base parameters */ 263 maxusers = MAXUSERS; 264 TUNABLE_INT_FETCH("kern.maxusers", &maxusers); 265 if (maxusers == 0) { 266 maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE); 267 if (maxusers < 32) 268 maxusers = 32; 269 #ifdef VM_MAX_AUTOTUNE_MAXUSERS 270 if (maxusers > VM_MAX_AUTOTUNE_MAXUSERS) 271 maxusers = VM_MAX_AUTOTUNE_MAXUSERS; 272 #endif 273 /* 274 * Scales down the function in which maxusers grows once 275 * we hit 384. 276 */ 277 if (maxusers > 384) 278 maxusers = 384 + ((maxusers - 384) / 8); 279 } 280 281 /* 282 * The following can be overridden after boot via sysctl. Note: 283 * unless overridden, these macros are ultimately based on maxusers. 284 * Limit maxproc so that kmap entries cannot be exhausted by 285 * processes. 286 */ 287 maxproc = NPROC; 288 TUNABLE_INT_FETCH("kern.maxproc", &maxproc); 289 if (maxproc > (physpages / 12)) 290 maxproc = physpages / 12; 291 if (maxproc > pid_max) 292 maxproc = pid_max; 293 maxprocperuid = (maxproc * 9) / 10; 294 295 /* 296 * The default limit for maxfiles is 1/12 of the number of 297 * physical page but not less than 16 times maxusers. 298 * At most it can be 1/6 the number of physical pages. 299 */ 300 maxfiles = imax(MAXFILES, physpages / 8); 301 TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles); 302 if (maxfiles > (physpages / 4)) 303 maxfiles = physpages / 4; 304 maxfilesperproc = (maxfiles / 10) * 9; 305 TUNABLE_INT_FETCH("kern.maxfilesperproc", &maxfilesperproc); 306 307 /* 308 * Cannot be changed after boot. 309 */ 310 nbuf = NBUF; 311 TUNABLE_INT_FETCH("kern.nbuf", &nbuf); 312 TUNABLE_INT_FETCH("kern.bio_transient_maxcnt", &bio_transient_maxcnt); 313 maxphys = MAXPHYS; 314 TUNABLE_ULONG_FETCH("kern.maxphys", &maxphys); 315 if (maxphys == 0) { 316 maxphys = MAXPHYS; 317 } else if (__bitcountl(maxphys) != 1) { /* power of two */ 318 if (flsl(maxphys) == NBBY * sizeof(maxphys)) 319 maxphys = MAXPHYS; 320 else 321 maxphys = 1UL << flsl(maxphys); 322 } 323 if (maxphys < PAGE_SIZE) 324 maxphys = MAXPHYS; 325 326 /* 327 * Physical buffers are pre-allocated buffers (struct buf) that 328 * are used as temporary holders for I/O, such as paging I/O. 329 */ 330 TUNABLE_INT_FETCH("kern.nswbuf", &nswbuf); 331 332 /* 333 * The default for maxpipekva is min(1/64 of the kernel address space, 334 * max(1/64 of main memory, 512KB)). See sys_pipe.c for more details. 335 */ 336 maxpipekva = ptoa(physpages / 64); 337 TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva); 338 if (maxpipekva < 512 * 1024) 339 maxpipekva = 512 * 1024; 340 if (maxpipekva > (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 64) 341 maxpipekva = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 342 64; 343 TSEXIT(); 344 } 345 346 /* 347 * Sysctl stringifying handler for kern.vm_guest. 348 */ 349 static int 350 sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS) 351 { 352 return (SYSCTL_OUT_STR(req, vm_guest_sysctl_names[vm_guest])); 353 } 354