1 /*- 2 * Copyright (c) 1980, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)param.c 8.3 (Berkeley) 8/20/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "opt_param.h" 41 #include "opt_msgbuf.h" 42 #include "opt_maxusers.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.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 52 #include <vm/vm.h> 53 #include <vm/vm_param.h> 54 #include <vm/pmap.h> 55 56 /* 57 * System parameter formulae. 58 */ 59 60 #ifndef HZ 61 # if defined(__mips__) || defined(__arm__) 62 # define HZ 100 63 # else 64 # define HZ 1000 65 # endif 66 # ifndef HZ_VM 67 # define HZ_VM 100 68 # endif 69 #else 70 # ifndef HZ_VM 71 # define HZ_VM HZ 72 # endif 73 #endif 74 #define NPROC (20 + 16 * maxusers) 75 #ifndef NBUF 76 #define NBUF 0 77 #endif 78 #ifndef MAXFILES 79 #define MAXFILES (40 + 32 * maxusers) 80 #endif 81 82 static int sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS); 83 84 int hz; /* system clock's frequency */ 85 int tick; /* usec per tick (1000000 / hz) */ 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; 95 int bio_transient_maxcnt; 96 int ngroups_max; /* max # groups per process */ 97 int nswbuf; 98 pid_t pid_max = PID_MAX; 99 long maxswzone; /* max swmeta KVA storage */ 100 long maxbcache; /* max buffer cache KVA storage */ 101 long maxpipekva; /* Limit on pipe KVA */ 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, nbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nbuf, 0, 113 "Number of buffers in the buffer cache"); 114 SYSCTL_INT(_kern, OID_AUTO, nswbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nswbuf, 0, 115 "Number of swap buffers"); 116 SYSCTL_INT(_kern, OID_AUTO, msgbufsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &msgbufsize, 0, 117 "Size of the kernel message buffer"); 118 SYSCTL_LONG(_kern, OID_AUTO, maxswzone, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxswzone, 0, 119 "Maximum memory for swap metadata"); 120 SYSCTL_LONG(_kern, OID_AUTO, maxbcache, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxbcache, 0, 121 "Maximum value of vfs.maxbufspace"); 122 SYSCTL_INT(_kern, OID_AUTO, bio_transient_maxcnt, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 123 &bio_transient_maxcnt, 0, 124 "Maximum number of transient BIOs mappings"); 125 SYSCTL_ULONG(_kern, OID_AUTO, maxtsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxtsiz, 0, 126 "Maximum text size"); 127 SYSCTL_ULONG(_kern, OID_AUTO, dfldsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dfldsiz, 0, 128 "Initial data size limit"); 129 SYSCTL_ULONG(_kern, OID_AUTO, maxdsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxdsiz, 0, 130 "Maximum data size"); 131 SYSCTL_ULONG(_kern, OID_AUTO, dflssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dflssiz, 0, 132 "Initial stack size limit"); 133 SYSCTL_ULONG(_kern, OID_AUTO, maxssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxssiz, 0, 134 "Maximum stack size"); 135 SYSCTL_ULONG(_kern, OID_AUTO, sgrowsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &sgrowsiz, 0, 136 "Amount to grow stack on a stack fault"); 137 SYSCTL_PROC(_kern, OID_AUTO, vm_guest, CTLFLAG_RD | CTLTYPE_STRING, 138 NULL, 0, sysctl_kern_vm_guest, "A", 139 "Virtual machine guest detected?"); 140 141 /* 142 * The elements of this array are ordered based upon the values of the 143 * corresponding enum VM_GUEST members. 144 */ 145 static const char *const vm_guest_sysctl_names[] = { 146 "none", 147 "generic", 148 "xen", 149 "hv", 150 "vmware", 151 "kvm", 152 "bhyve", 153 NULL 154 }; 155 CTASSERT(nitems(vm_guest_sysctl_names) - 1 == VM_LAST); 156 157 /* 158 * Boot time overrides that are not scaled against main memory 159 */ 160 void 161 init_param1(void) 162 { 163 164 #if !defined(__mips__) && !defined(__arm64__) && !defined(__sparc64__) 165 TUNABLE_INT_FETCH("kern.kstack_pages", &kstack_pages); 166 #endif 167 hz = -1; 168 TUNABLE_INT_FETCH("kern.hz", &hz); 169 if (hz == -1) 170 hz = vm_guest > VM_GUEST_NO ? HZ_VM : HZ; 171 tick = 1000000 / hz; 172 tick_sbt = SBT_1S / hz; 173 tick_bt = sbttobt(tick_sbt); 174 175 /* 176 * Arrange for ticks to wrap 10 minutes after boot to help catch 177 * sign problems sooner. 178 */ 179 ticks = INT_MAX - (hz * 10 * 60); 180 181 #ifdef VM_SWZONE_SIZE_MAX 182 maxswzone = VM_SWZONE_SIZE_MAX; 183 #endif 184 TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone); 185 #ifdef VM_BCACHE_SIZE_MAX 186 maxbcache = VM_BCACHE_SIZE_MAX; 187 #endif 188 TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache); 189 msgbufsize = MSGBUF_SIZE; 190 TUNABLE_INT_FETCH("kern.msgbufsize", &msgbufsize); 191 192 maxtsiz = MAXTSIZ; 193 TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz); 194 dfldsiz = DFLDSIZ; 195 TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz); 196 maxdsiz = MAXDSIZ; 197 TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz); 198 dflssiz = DFLSSIZ; 199 TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz); 200 maxssiz = MAXSSIZ; 201 TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz); 202 sgrowsiz = SGROWSIZ; 203 TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz); 204 205 /* 206 * Let the administrator set {NGROUPS_MAX}, but disallow values 207 * less than NGROUPS_MAX which would violate POSIX.1-2008 or 208 * greater than INT_MAX-1 which would result in overflow. 209 */ 210 ngroups_max = NGROUPS_MAX; 211 TUNABLE_INT_FETCH("kern.ngroups", &ngroups_max); 212 if (ngroups_max < NGROUPS_MAX) 213 ngroups_max = NGROUPS_MAX; 214 215 /* 216 * Only allow to lower the maximal pid. 217 * Prevent setting up a non-bootable system if pid_max is too low. 218 */ 219 TUNABLE_INT_FETCH("kern.pid_max", &pid_max); 220 if (pid_max > PID_MAX) 221 pid_max = PID_MAX; 222 else if (pid_max < 300) 223 pid_max = 300; 224 225 TUNABLE_INT_FETCH("vfs.unmapped_buf_allowed", &unmapped_buf_allowed); 226 } 227 228 /* 229 * Boot time overrides that are scaled against main memory 230 */ 231 void 232 init_param2(long physpages) 233 { 234 235 /* Base parameters */ 236 maxusers = MAXUSERS; 237 TUNABLE_INT_FETCH("kern.maxusers", &maxusers); 238 if (maxusers == 0) { 239 maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE); 240 if (maxusers < 32) 241 maxusers = 32; 242 #ifdef VM_MAX_AUTOTUNE_MAXUSERS 243 if (maxusers > VM_MAX_AUTOTUNE_MAXUSERS) 244 maxusers = VM_MAX_AUTOTUNE_MAXUSERS; 245 #endif 246 /* 247 * Scales down the function in which maxusers grows once 248 * we hit 384. 249 */ 250 if (maxusers > 384) 251 maxusers = 384 + ((maxusers - 384) / 8); 252 } 253 254 /* 255 * The following can be overridden after boot via sysctl. Note: 256 * unless overriden, these macros are ultimately based on maxusers. 257 * Limit maxproc so that kmap entries cannot be exhausted by 258 * processes. 259 */ 260 maxproc = NPROC; 261 TUNABLE_INT_FETCH("kern.maxproc", &maxproc); 262 if (maxproc > (physpages / 12)) 263 maxproc = physpages / 12; 264 if (maxproc > pid_max) 265 maxproc = pid_max; 266 maxprocperuid = (maxproc * 9) / 10; 267 268 /* 269 * The default limit for maxfiles is 1/12 of the number of 270 * physical page but not less than 16 times maxusers. 271 * At most it can be 1/6 the number of physical pages. 272 */ 273 maxfiles = imax(MAXFILES, physpages / 8); 274 TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles); 275 if (maxfiles > (physpages / 4)) 276 maxfiles = physpages / 4; 277 maxfilesperproc = (maxfiles / 10) * 9; 278 TUNABLE_INT_FETCH("kern.maxfilesperproc", &maxfilesperproc); 279 280 /* 281 * Cannot be changed after boot. 282 */ 283 nbuf = NBUF; 284 TUNABLE_INT_FETCH("kern.nbuf", &nbuf); 285 TUNABLE_INT_FETCH("kern.bio_transient_maxcnt", &bio_transient_maxcnt); 286 287 /* 288 * The default for maxpipekva is min(1/64 of the kernel address space, 289 * max(1/64 of main memory, 512KB)). See sys_pipe.c for more details. 290 */ 291 maxpipekva = (physpages / 64) * PAGE_SIZE; 292 TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva); 293 if (maxpipekva < 512 * 1024) 294 maxpipekva = 512 * 1024; 295 if (maxpipekva > (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 64) 296 maxpipekva = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 297 64; 298 } 299 300 /* 301 * Sysctl stringifying handler for kern.vm_guest. 302 */ 303 static int 304 sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS) 305 { 306 return (SYSCTL_OUT_STR(req, vm_guest_sysctl_names[vm_guest])); 307 } 308