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 37 #include <sys/cdefs.h> 38 #include "opt_param.h" 39 #include "opt_msgbuf.h" 40 #include "opt_maxphys.h" 41 #include "opt_maxusers.h" 42 43 #include <sys/param.h> 44 #include <sys/_maxphys.h> 45 #include <sys/systm.h> 46 #include <sys/buf.h> 47 #include <sys/kernel.h> 48 #include <sys/limits.h> 49 #include <sys/msgbuf.h> 50 #include <sys/sysctl.h> 51 #include <sys/proc.h> 52 #include <sys/vnode.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 # define HZ 1000 64 # ifndef HZ_VM 65 # define HZ_VM 100 66 # endif 67 #else 68 # ifndef HZ_VM 69 # define HZ_VM HZ 70 # endif 71 #endif 72 #define NPROC (20 + 16 * maxusers) 73 #ifndef NBUF 74 #define NBUF 0 75 #endif 76 #ifndef MAXFILES 77 #define MAXFILES (40 + 32 * maxusers) 78 #endif 79 80 static int sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS); 81 82 int hz; /* system clock's frequency */ 83 int tick; /* usec per tick (1000000 / hz) */ 84 time_t tick_seconds_max; /* max hz * seconds an integer can hold */ 85 struct bintime tick_bt; /* bintime per tick (1s / hz) */ 86 sbintime_t tick_sbt; 87 int maxusers; /* base tunable */ 88 int maxproc; /* maximum # of processes */ 89 int maxprocperuid; /* max # of procs per user */ 90 int maxfiles; /* sys. wide open files limit */ 91 int maxfilesperproc; /* per-proc open files limit */ 92 int msgbufsize; /* size of kernel message buffer */ 93 int nbuf; /* number of bcache bufs */ 94 int bio_transient_maxcnt; 95 int ngroups_max; /* max # groups per process */ 96 int nswbuf; 97 pid_t pid_max = PID_MAX; 98 u_long maxswzone; /* max swmeta KVA storage */ 99 u_long maxbcache; /* max buffer cache KVA storage */ 100 u_long maxpipekva; /* Limit on pipe KVA */ 101 u_long maxphys; /* max raw I/O transfer size */ 102 int vm_guest = VM_GUEST_NO; /* Running as virtual machine guest? */ 103 u_long maxtsiz; /* max text size */ 104 u_long dfldsiz; /* initial data size limit */ 105 u_long maxdsiz; /* max data size */ 106 u_long dflssiz; /* initial stack size limit */ 107 u_long maxssiz; /* max stack size */ 108 u_long sgrowsiz; /* amount to grow stack */ 109 110 SYSCTL_INT(_kern, OID_AUTO, hz, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &hz, 0, 111 "Number of clock ticks per second"); 112 SYSCTL_INT(_kern, OID_AUTO, hz_max, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, HZ_MAXIMUM, 113 "Maximum hz value supported"); 114 SYSCTL_INT(_kern, OID_AUTO, hz_min, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, HZ_MINIMUM, 115 "Minimum hz value supported"); 116 SYSCTL_INT(_kern, OID_AUTO, nbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nbuf, 0, 117 "Number of buffers in the buffer cache"); 118 SYSCTL_INT(_kern, OID_AUTO, nswbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nswbuf, 0, 119 "Number of swap buffers"); 120 SYSCTL_INT(_kern, OID_AUTO, msgbufsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &msgbufsize, 0, 121 "Size of the kernel message buffer"); 122 SYSCTL_LONG(_kern, OID_AUTO, maxswzone, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxswzone, 0, 123 "Maximum memory for swap metadata"); 124 SYSCTL_LONG(_kern, OID_AUTO, maxbcache, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxbcache, 0, 125 "Maximum value of vfs.maxbufspace"); 126 SYSCTL_INT(_kern, OID_AUTO, bio_transient_maxcnt, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 127 &bio_transient_maxcnt, 0, 128 "Maximum number of transient BIOs mappings"); 129 SYSCTL_ULONG(_kern, OID_AUTO, maxtsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxtsiz, 0, 130 "Maximum text size"); 131 SYSCTL_ULONG(_kern, OID_AUTO, dfldsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dfldsiz, 0, 132 "Initial data size limit"); 133 SYSCTL_ULONG(_kern, OID_AUTO, maxdsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxdsiz, 0, 134 "Maximum data size"); 135 SYSCTL_ULONG(_kern, OID_AUTO, dflssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dflssiz, 0, 136 "Initial stack size limit"); 137 SYSCTL_ULONG(_kern, OID_AUTO, maxssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxssiz, 0, 138 "Maximum stack size"); 139 SYSCTL_ULONG(_kern, OID_AUTO, sgrowsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &sgrowsiz, 0, 140 "Amount to grow stack on a stack fault"); 141 SYSCTL_PROC(_kern, OID_AUTO, vm_guest, 142 CTLFLAG_RD | CTLTYPE_STRING | CTLFLAG_MPSAFE, NULL, 0, 143 sysctl_kern_vm_guest, "A", 144 "Virtual machine guest detected?"); 145 146 /* 147 * The elements of this array are ordered based upon the values of the 148 * corresponding enum VM_GUEST members. 149 */ 150 static const char *const vm_guest_sysctl_names[] = { 151 [VM_GUEST_NO] = "none", 152 [VM_GUEST_VM] = "generic", 153 [VM_GUEST_XEN] = "xen", 154 [VM_GUEST_HV] = "hv", 155 [VM_GUEST_VMWARE] = "vmware", 156 [VM_GUEST_KVM] = "kvm", 157 [VM_GUEST_BHYVE] = "bhyve", 158 [VM_GUEST_VBOX] = "vbox", 159 [VM_GUEST_PARALLELS] = "parallels", 160 }; 161 _Static_assert(nitems(vm_guest_sysctl_names) == VM_GUEST_LAST, 162 "new vm guest type not added to vm_guest_sysctl_names"); 163 164 /* 165 * Boot time overrides that are not scaled against main memory 166 */ 167 void 168 init_param1(void) 169 { 170 171 TSENTER(); 172 173 /* 174 * arm64 and riscv currently hard-code the thread0 kstack size 175 * to KSTACK_PAGES, ignoring the tunable. 176 */ 177 TUNABLE_INT_FETCH("kern.kstack_pages", &kstack_pages); 178 179 hz = -1; 180 TUNABLE_INT_FETCH("kern.hz", &hz); 181 if (hz == -1) 182 hz = vm_guest > VM_GUEST_NO ? HZ_VM : HZ; 183 184 /* range check the "hz" value */ 185 if (__predict_false(hz < HZ_MINIMUM)) 186 hz = HZ_MINIMUM; 187 else if (__predict_false(hz > HZ_MAXIMUM)) 188 hz = HZ_MAXIMUM; 189 190 tick = 1000000 / hz; 191 tick_sbt = SBT_1S / hz; 192 tick_bt = sbttobt(tick_sbt); 193 tick_seconds_max = INT_MAX / hz; 194 195 /* 196 * Arrange for ticks to wrap 10 minutes after boot to help catch 197 * sign problems sooner. 198 */ 199 ticks = INT_MAX - (hz * 10 * 60); 200 201 vn_lock_pair_pause_max = hz / 100; 202 if (vn_lock_pair_pause_max == 0) 203 vn_lock_pair_pause_max = 1; 204 205 #ifdef VM_SWZONE_SIZE_MAX 206 maxswzone = VM_SWZONE_SIZE_MAX; 207 #endif 208 TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone); 209 #ifdef VM_BCACHE_SIZE_MAX 210 maxbcache = VM_BCACHE_SIZE_MAX; 211 #endif 212 TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache); 213 msgbufsize = MSGBUF_SIZE; 214 TUNABLE_INT_FETCH("kern.msgbufsize", &msgbufsize); 215 216 maxtsiz = MAXTSIZ; 217 TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz); 218 dfldsiz = DFLDSIZ; 219 TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz); 220 maxdsiz = MAXDSIZ; 221 TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz); 222 dflssiz = DFLSSIZ; 223 TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz); 224 maxssiz = MAXSSIZ; 225 TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz); 226 sgrowsiz = SGROWSIZ; 227 TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz); 228 229 /* 230 * Let the administrator set {NGROUPS_MAX}, but disallow values 231 * less than NGROUPS_MAX which would violate POSIX.1-2008 or 232 * greater than INT_MAX-1 which would result in overflow. 233 */ 234 ngroups_max = NGROUPS_MAX; 235 TUNABLE_INT_FETCH("kern.ngroups", &ngroups_max); 236 if (ngroups_max < NGROUPS_MAX) 237 ngroups_max = NGROUPS_MAX; 238 239 /* 240 * Only allow to lower the maximal pid. 241 * Prevent setting up a non-bootable system if pid_max is too low. 242 */ 243 TUNABLE_INT_FETCH("kern.pid_max", &pid_max); 244 if (pid_max > PID_MAX) 245 pid_max = PID_MAX; 246 else if (pid_max < 300) 247 pid_max = 300; 248 249 TUNABLE_INT_FETCH("vfs.unmapped_buf_allowed", &unmapped_buf_allowed); 250 TSEXIT(); 251 } 252 253 /* 254 * Boot time overrides that are scaled against main memory 255 */ 256 void 257 init_param2(long physpages) 258 { 259 260 TSENTER(); 261 /* Base parameters */ 262 maxusers = MAXUSERS; 263 TUNABLE_INT_FETCH("kern.maxusers", &maxusers); 264 if (maxusers == 0) { 265 maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE); 266 if (maxusers < 32) 267 maxusers = 32; 268 #ifdef VM_MAX_AUTOTUNE_MAXUSERS 269 if (maxusers > VM_MAX_AUTOTUNE_MAXUSERS) 270 maxusers = VM_MAX_AUTOTUNE_MAXUSERS; 271 #endif 272 /* 273 * Scales down the function in which maxusers grows once 274 * we hit 384. 275 */ 276 if (maxusers > 384) 277 maxusers = 384 + ((maxusers - 384) / 8); 278 } 279 280 /* 281 * The following can be overridden after boot via sysctl. Note: 282 * unless overridden, these macros are ultimately based on maxusers. 283 * Limit maxproc so that kmap entries cannot be exhausted by 284 * processes. 285 */ 286 maxproc = NPROC; 287 TUNABLE_INT_FETCH("kern.maxproc", &maxproc); 288 if (maxproc > (physpages / 12)) 289 maxproc = physpages / 12; 290 if (maxproc > pid_max) 291 maxproc = pid_max; 292 maxprocperuid = (maxproc * 9) / 10; 293 294 /* 295 * The default limit for maxfiles is 1/12 of the number of 296 * physical page but not less than 16 times maxusers. 297 * At most it can be 1/6 the number of physical pages. 298 */ 299 maxfiles = imax(MAXFILES, physpages / 8); 300 TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles); 301 if (maxfiles > (physpages / 4)) 302 maxfiles = physpages / 4; 303 maxfilesperproc = (maxfiles / 10) * 9; 304 TUNABLE_INT_FETCH("kern.maxfilesperproc", &maxfilesperproc); 305 306 /* 307 * Cannot be changed after boot. 308 */ 309 nbuf = NBUF; 310 TUNABLE_INT_FETCH("kern.nbuf", &nbuf); 311 TUNABLE_INT_FETCH("kern.bio_transient_maxcnt", &bio_transient_maxcnt); 312 maxphys = MAXPHYS; 313 TUNABLE_ULONG_FETCH("kern.maxphys", &maxphys); 314 if (maxphys == 0) { 315 maxphys = MAXPHYS; 316 } else if (__bitcountl(maxphys) != 1) { /* power of two */ 317 if (flsl(maxphys) == NBBY * sizeof(maxphys)) 318 maxphys = MAXPHYS; 319 else 320 maxphys = 1UL << flsl(maxphys); 321 } 322 if (maxphys < PAGE_SIZE) 323 maxphys = MAXPHYS; 324 325 /* 326 * Physical buffers are pre-allocated buffers (struct buf) that 327 * are used as temporary holders for I/O, such as paging I/O. 328 */ 329 TUNABLE_INT_FETCH("kern.nswbuf", &nswbuf); 330 331 /* 332 * The default for maxpipekva is min(1/64 of the kernel address space, 333 * max(1/64 of main memory, 512KB)). See sys_pipe.c for more details. 334 */ 335 maxpipekva = ptoa(physpages / 64); 336 TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva); 337 if (maxpipekva < 512 * 1024) 338 maxpipekva = 512 * 1024; 339 if (maxpipekva > (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 64) 340 maxpipekva = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 341 64; 342 TSEXIT(); 343 } 344 345 /* 346 * Sysctl stringifying handler for kern.vm_guest. 347 */ 348 static int 349 sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS) 350 { 351 return (SYSCTL_OUT_STR(req, vm_guest_sysctl_names[vm_guest])); 352 } 353