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/systm.h> 45 #include <sys/buf.h> 46 #include <sys/kernel.h> 47 #include <sys/limits.h> 48 #include <sys/msgbuf.h> 49 #include <sys/sysctl.h> 50 #include <sys/proc.h> 51 #include <sys/vnode.h> 52 53 #include <vm/vm.h> 54 #include <vm/vm_param.h> 55 #include <vm/pmap.h> 56 57 /* 58 * System parameter formulae. 59 */ 60 61 #ifndef HZ 62 # define HZ 1000 63 # ifndef HZ_VM 64 # define HZ_VM 100 65 # endif 66 #else 67 # ifndef HZ_VM 68 # define HZ_VM HZ 69 # endif 70 #endif 71 #define NPROC (20 + 16 * maxusers) 72 #ifndef NBUF 73 #define NBUF 0 74 #endif 75 #ifndef MAXFILES 76 #define MAXFILES (40 + 32 * maxusers) 77 #endif 78 79 static int sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS); 80 81 int hz; /* system clock's frequency */ 82 int tick; /* usec per tick (1000000 / hz) */ 83 time_t tick_seconds_max; /* max hz * seconds an integer can hold */ 84 struct bintime tick_bt; /* bintime per tick (1s / hz) */ 85 sbintime_t tick_sbt; 86 int maxusers; /* base tunable */ 87 int maxproc; /* maximum # of processes */ 88 int maxprocperuid; /* max # of procs per user */ 89 int maxfiles; /* sys. wide open files limit */ 90 int maxfilesperproc; /* per-proc open files limit */ 91 int msgbufsize; /* size of kernel message buffer */ 92 int nbuf; /* number of bcache bufs */ 93 int bio_transient_maxcnt; 94 int ngroups_max; /* max # groups per process */ 95 int nswbuf; 96 pid_t pid_max = PID_MAX; 97 u_long maxswzone; /* max swmeta KVA storage */ 98 u_long maxbcache; /* max buffer cache KVA storage */ 99 u_long maxpipekva; /* Limit on pipe KVA */ 100 u_long maxphys; /* max raw I/O transfer size */ 101 int vm_guest = VM_GUEST_NO; /* Running as virtual machine guest? */ 102 u_long maxtsiz; /* max text size */ 103 u_long dfldsiz; /* initial data size limit */ 104 u_long maxdsiz; /* max data size */ 105 u_long dflssiz; /* initial stack size limit */ 106 u_long maxssiz; /* max stack size */ 107 u_long sgrowsiz; /* amount to grow stack */ 108 109 SYSCTL_INT(_kern, OID_AUTO, hz, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &hz, 0, 110 "Number of clock ticks per second"); 111 SYSCTL_INT(_kern, OID_AUTO, hz_max, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, HZ_MAXIMUM, 112 "Maximum hz value supported"); 113 SYSCTL_INT(_kern, OID_AUTO, hz_min, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, HZ_MINIMUM, 114 "Minimum hz value supported"); 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 }; 160 _Static_assert(nitems(vm_guest_sysctl_names) == VM_LAST, 161 "new vm guest type not added to vm_guest_sysctl_names"); 162 163 /* 164 * Boot time overrides that are not scaled against main memory 165 */ 166 void 167 init_param1(void) 168 { 169 170 TSENTER(); 171 172 /* 173 * arm64 and riscv currently hard-code the thread0 kstack size 174 * to KSTACK_PAGES, ignoring the tunable. 175 */ 176 TUNABLE_INT_FETCH("kern.kstack_pages", &kstack_pages); 177 178 hz = -1; 179 TUNABLE_INT_FETCH("kern.hz", &hz); 180 if (hz == -1) 181 hz = vm_guest > VM_GUEST_NO ? HZ_VM : HZ; 182 183 /* range check the "hz" value */ 184 if (__predict_false(hz < HZ_MINIMUM)) 185 hz = HZ_MINIMUM; 186 else if (__predict_false(hz > HZ_MAXIMUM)) 187 hz = HZ_MAXIMUM; 188 189 tick = 1000000 / hz; 190 tick_sbt = SBT_1S / hz; 191 tick_bt = sbttobt(tick_sbt); 192 tick_seconds_max = INT_MAX / hz; 193 194 /* 195 * Arrange for ticks to wrap 10 minutes after boot to help catch 196 * sign problems sooner. 197 */ 198 ticks = INT_MAX - (hz * 10 * 60); 199 200 vn_lock_pair_pause_max = hz / 100; 201 if (vn_lock_pair_pause_max == 0) 202 vn_lock_pair_pause_max = 1; 203 204 #ifdef VM_SWZONE_SIZE_MAX 205 maxswzone = VM_SWZONE_SIZE_MAX; 206 #endif 207 TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone); 208 #ifdef VM_BCACHE_SIZE_MAX 209 maxbcache = VM_BCACHE_SIZE_MAX; 210 #endif 211 TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache); 212 msgbufsize = MSGBUF_SIZE; 213 TUNABLE_INT_FETCH("kern.msgbufsize", &msgbufsize); 214 215 maxtsiz = MAXTSIZ; 216 TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz); 217 dfldsiz = DFLDSIZ; 218 TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz); 219 maxdsiz = MAXDSIZ; 220 TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz); 221 dflssiz = DFLSSIZ; 222 TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz); 223 maxssiz = MAXSSIZ; 224 TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz); 225 sgrowsiz = SGROWSIZ; 226 TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz); 227 228 /* 229 * Let the administrator set {NGROUPS_MAX}, but disallow values 230 * less than NGROUPS_MAX which would violate POSIX.1-2008 or 231 * greater than INT_MAX-1 which would result in overflow. 232 */ 233 ngroups_max = NGROUPS_MAX; 234 TUNABLE_INT_FETCH("kern.ngroups", &ngroups_max); 235 if (ngroups_max < NGROUPS_MAX) 236 ngroups_max = NGROUPS_MAX; 237 238 /* 239 * Only allow to lower the maximal pid. 240 * Prevent setting up a non-bootable system if pid_max is too low. 241 */ 242 TUNABLE_INT_FETCH("kern.pid_max", &pid_max); 243 if (pid_max > PID_MAX) 244 pid_max = PID_MAX; 245 else if (pid_max < 300) 246 pid_max = 300; 247 248 TUNABLE_INT_FETCH("vfs.unmapped_buf_allowed", &unmapped_buf_allowed); 249 TSEXIT(); 250 } 251 252 /* 253 * Boot time overrides that are scaled against main memory 254 */ 255 void 256 init_param2(long physpages) 257 { 258 259 TSENTER(); 260 /* Base parameters */ 261 maxusers = MAXUSERS; 262 TUNABLE_INT_FETCH("kern.maxusers", &maxusers); 263 if (maxusers == 0) { 264 maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE); 265 if (maxusers < 32) 266 maxusers = 32; 267 #ifdef VM_MAX_AUTOTUNE_MAXUSERS 268 if (maxusers > VM_MAX_AUTOTUNE_MAXUSERS) 269 maxusers = VM_MAX_AUTOTUNE_MAXUSERS; 270 #endif 271 /* 272 * Scales down the function in which maxusers grows once 273 * we hit 384. 274 */ 275 if (maxusers > 384) 276 maxusers = 384 + ((maxusers - 384) / 8); 277 } 278 279 /* 280 * The following can be overridden after boot via sysctl. Note: 281 * unless overridden, these macros are ultimately based on maxusers. 282 * Limit maxproc so that kmap entries cannot be exhausted by 283 * processes. 284 */ 285 maxproc = NPROC; 286 TUNABLE_INT_FETCH("kern.maxproc", &maxproc); 287 if (maxproc > (physpages / 12)) 288 maxproc = physpages / 12; 289 if (maxproc > pid_max) 290 maxproc = pid_max; 291 maxprocperuid = (maxproc * 9) / 10; 292 293 /* 294 * The default limit for maxfiles is 1/12 of the number of 295 * physical page but not less than 16 times maxusers. 296 * At most it can be 1/6 the number of physical pages. 297 */ 298 maxfiles = imax(MAXFILES, physpages / 8); 299 TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles); 300 if (maxfiles > (physpages / 4)) 301 maxfiles = physpages / 4; 302 maxfilesperproc = (maxfiles / 10) * 9; 303 TUNABLE_INT_FETCH("kern.maxfilesperproc", &maxfilesperproc); 304 305 /* 306 * Cannot be changed after boot. 307 */ 308 nbuf = NBUF; 309 TUNABLE_INT_FETCH("kern.nbuf", &nbuf); 310 TUNABLE_INT_FETCH("kern.bio_transient_maxcnt", &bio_transient_maxcnt); 311 maxphys = MAXPHYS; 312 TUNABLE_ULONG_FETCH("kern.maxphys", &maxphys); 313 if (maxphys == 0) { 314 maxphys = MAXPHYS; 315 } else if (__bitcountl(maxphys) != 1) { /* power of two */ 316 if (flsl(maxphys) == NBBY * sizeof(maxphys)) 317 maxphys = MAXPHYS; 318 else 319 maxphys = 1UL << flsl(maxphys); 320 } 321 if (maxphys < PAGE_SIZE) 322 maxphys = MAXPHYS; 323 324 /* 325 * Physical buffers are pre-allocated buffers (struct buf) that 326 * are used as temporary holders for I/O, such as paging I/O. 327 */ 328 TUNABLE_INT_FETCH("kern.nswbuf", &nswbuf); 329 330 /* 331 * The default for maxpipekva is min(1/64 of the kernel address space, 332 * max(1/64 of main memory, 512KB)). See sys_pipe.c for more details. 333 */ 334 maxpipekva = ptoa(physpages / 64); 335 TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva); 336 if (maxpipekva < 512 * 1024) 337 maxpipekva = 512 * 1024; 338 if (maxpipekva > (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 64) 339 maxpipekva = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 340 64; 341 TSEXIT(); 342 } 343 344 /* 345 * Sysctl stringifying handler for kern.vm_guest. 346 */ 347 static int 348 sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS) 349 { 350 return (SYSCTL_OUT_STR(req, vm_guest_sysctl_names[vm_guest])); 351 } 352