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 * 4. 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 (maxproc * 2) 80 #endif 81 82 static int sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS); 83 84 int hz; 85 int tick; 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 ncallout; /* maximum # of timer events */ 93 int nbuf; 94 int ngroups_max; /* max # groups per process */ 95 int nswbuf; 96 quad_t maxmbufmem; /* max mbuf memory */ 97 pid_t pid_max = PID_MAX; 98 long maxswzone; /* max swmeta KVA storage */ 99 long maxbcache; /* max buffer cache KVA storage */ 100 long maxpipekva; /* Limit on pipe KVA */ 101 int vm_guest; /* 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, &hz, 0, 110 "Number of clock ticks per second"); 111 SYSCTL_INT(_kern, OID_AUTO, ncallout, CTLFLAG_RDTUN, &ncallout, 0, 112 "Number of pre-allocated timer events"); 113 SYSCTL_INT(_kern, OID_AUTO, nbuf, CTLFLAG_RDTUN, &nbuf, 0, 114 "Number of buffers in the buffer cache"); 115 SYSCTL_INT(_kern, OID_AUTO, nswbuf, CTLFLAG_RDTUN, &nswbuf, 0, 116 "Number of swap buffers"); 117 SYSCTL_INT(_kern, OID_AUTO, msgbufsize, CTLFLAG_RDTUN, &msgbufsize, 0, 118 "Size of the kernel message buffer"); 119 SYSCTL_LONG(_kern, OID_AUTO, maxswzone, CTLFLAG_RDTUN, &maxswzone, 0, 120 "Maximum memory for swap metadata"); 121 SYSCTL_LONG(_kern, OID_AUTO, maxbcache, CTLFLAG_RDTUN, &maxbcache, 0, 122 "Maximum value of vfs.maxbufspace"); 123 SYSCTL_ULONG(_kern, OID_AUTO, maxtsiz, CTLFLAG_RW | CTLFLAG_TUN, &maxtsiz, 0, 124 "Maximum text size"); 125 SYSCTL_ULONG(_kern, OID_AUTO, dfldsiz, CTLFLAG_RW | CTLFLAG_TUN, &dfldsiz, 0, 126 "Initial data size limit"); 127 SYSCTL_ULONG(_kern, OID_AUTO, maxdsiz, CTLFLAG_RW | CTLFLAG_TUN, &maxdsiz, 0, 128 "Maximum data size"); 129 SYSCTL_ULONG(_kern, OID_AUTO, dflssiz, CTLFLAG_RW | CTLFLAG_TUN, &dflssiz, 0, 130 "Initial stack size limit"); 131 SYSCTL_ULONG(_kern, OID_AUTO, maxssiz, CTLFLAG_RW | CTLFLAG_TUN, &maxssiz, 0, 132 "Maximum stack size"); 133 SYSCTL_ULONG(_kern, OID_AUTO, sgrowsiz, CTLFLAG_RW | CTLFLAG_TUN, &sgrowsiz, 0, 134 "Amount to grow stack on a stack fault"); 135 SYSCTL_PROC(_kern, OID_AUTO, vm_guest, CTLFLAG_RD | CTLTYPE_STRING, 136 NULL, 0, sysctl_kern_vm_guest, "A", 137 "Virtual machine guest detected? (none|generic|xen)"); 138 139 /* 140 * These have to be allocated somewhere; allocating 141 * them here forces loader errors if this file is omitted 142 * (if they've been externed everywhere else; hah!). 143 */ 144 struct buf *swbuf; 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 "none", 152 "generic", 153 "xen", 154 NULL 155 }; 156 157 #ifndef XEN 158 static const char *const vm_bnames[] = { 159 "QEMU", /* QEMU */ 160 "Plex86", /* Plex86 */ 161 "Bochs", /* Bochs */ 162 "Xen", /* Xen */ 163 NULL 164 }; 165 166 static const char *const vm_pnames[] = { 167 "VMware Virtual Platform", /* VMWare VM */ 168 "Virtual Machine", /* Microsoft VirtualPC */ 169 "VirtualBox", /* Sun xVM VirtualBox */ 170 "Parallels Virtual Platform", /* Parallels VM */ 171 NULL 172 }; 173 174 175 /* 176 * Detect known Virtual Machine hosts by inspecting the emulated BIOS. 177 */ 178 static enum VM_GUEST 179 detect_virtual(void) 180 { 181 char *sysenv; 182 int i; 183 184 sysenv = getenv("smbios.bios.vendor"); 185 if (sysenv != NULL) { 186 for (i = 0; vm_bnames[i] != NULL; i++) 187 if (strcmp(sysenv, vm_bnames[i]) == 0) { 188 freeenv(sysenv); 189 return (VM_GUEST_VM); 190 } 191 freeenv(sysenv); 192 } 193 sysenv = getenv("smbios.system.product"); 194 if (sysenv != NULL) { 195 for (i = 0; vm_pnames[i] != NULL; i++) 196 if (strcmp(sysenv, vm_pnames[i]) == 0) { 197 freeenv(sysenv); 198 return (VM_GUEST_VM); 199 } 200 freeenv(sysenv); 201 } 202 return (VM_GUEST_NO); 203 } 204 #endif 205 206 /* 207 * Boot time overrides that are not scaled against main memory 208 */ 209 void 210 init_param1(void) 211 { 212 #ifndef XEN 213 vm_guest = detect_virtual(); 214 #else 215 vm_guest = VM_GUEST_XEN; 216 #endif 217 hz = -1; 218 TUNABLE_INT_FETCH("kern.hz", &hz); 219 if (hz == -1) 220 hz = vm_guest > VM_GUEST_NO ? HZ_VM : HZ; 221 tick = 1000000 / hz; 222 223 #ifdef VM_SWZONE_SIZE_MAX 224 maxswzone = VM_SWZONE_SIZE_MAX; 225 #endif 226 TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone); 227 #ifdef VM_BCACHE_SIZE_MAX 228 maxbcache = VM_BCACHE_SIZE_MAX; 229 #endif 230 TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache); 231 msgbufsize = MSGBUF_SIZE; 232 TUNABLE_INT_FETCH("kern.msgbufsize", &msgbufsize); 233 234 maxtsiz = MAXTSIZ; 235 TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz); 236 dfldsiz = DFLDSIZ; 237 TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz); 238 maxdsiz = MAXDSIZ; 239 TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz); 240 dflssiz = DFLSSIZ; 241 TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz); 242 maxssiz = MAXSSIZ; 243 TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz); 244 sgrowsiz = SGROWSIZ; 245 TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz); 246 247 /* 248 * Let the administrator set {NGROUPS_MAX}, but disallow values 249 * less than NGROUPS_MAX which would violate POSIX.1-2008 or 250 * greater than INT_MAX-1 which would result in overflow. 251 */ 252 ngroups_max = NGROUPS_MAX; 253 TUNABLE_INT_FETCH("kern.ngroups", &ngroups_max); 254 if (ngroups_max < NGROUPS_MAX) 255 ngroups_max = NGROUPS_MAX; 256 257 /* 258 * Only allow to lower the maximal pid. 259 * Prevent setting up a non-bootable system if pid_max is too low. 260 */ 261 TUNABLE_INT_FETCH("kern.pid_max", &pid_max); 262 if (pid_max > PID_MAX) 263 pid_max = PID_MAX; 264 else if (pid_max < 300) 265 pid_max = 300; 266 } 267 268 /* 269 * Boot time overrides that are scaled against main memory 270 */ 271 void 272 init_param2(long physpages) 273 { 274 quad_t realmem; 275 276 /* Base parameters */ 277 maxusers = MAXUSERS; 278 TUNABLE_INT_FETCH("kern.maxusers", &maxusers); 279 if (maxusers == 0) { 280 maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE); 281 if (maxusers < 32) 282 maxusers = 32; 283 #ifdef VM_MAX_AUTOTUNE_MAXUSERS 284 if (maxusers > VM_MAX_AUTOTUNE_MAXUSERS) 285 maxusers = VM_MAX_AUTOTUNE_MAXUSERS; 286 #endif 287 /* 288 * Scales down the function in which maxusers grows once 289 * we hit 384. 290 */ 291 if (maxusers > 384) 292 maxusers = 384 + ((maxusers - 384) / 8); 293 } 294 295 /* 296 * The following can be overridden after boot via sysctl. Note: 297 * unless overriden, these macros are ultimately based on maxusers. 298 * Limit maxproc so that kmap entries cannot be exhausted by 299 * processes. 300 */ 301 maxproc = NPROC; 302 TUNABLE_INT_FETCH("kern.maxproc", &maxproc); 303 if (maxproc > (physpages / 12)) 304 maxproc = physpages / 12; 305 maxprocperuid = (maxproc * 9) / 10; 306 307 /* 308 * The default limit for maxfiles is 1/12 of the number of 309 * physical page but not less than 16 times maxusers. 310 * At most it can be 1/6 the number of physical pages. 311 */ 312 maxfiles = imax(MAXFILES, physpages / 8); 313 TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles); 314 if (maxfiles > (physpages / 4)) 315 maxfiles = physpages / 4; 316 maxfilesperproc = (maxfiles / 10) * 9; 317 318 /* 319 * Cannot be changed after boot. 320 */ 321 nbuf = NBUF; 322 TUNABLE_INT_FETCH("kern.nbuf", &nbuf); 323 324 /* 325 * XXX: Does the callout wheel have to be so big? 326 */ 327 ncallout = 16 + maxproc + maxfiles; 328 TUNABLE_INT_FETCH("kern.ncallout", &ncallout); 329 330 /* 331 * The default limit for all mbuf related memory is 1/2 of all 332 * available kernel memory (physical or kmem). 333 * At most it can be 3/4 of available kernel memory. 334 */ 335 realmem = qmin((quad_t)physpages * PAGE_SIZE, 336 VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS); 337 maxmbufmem = realmem / 2; 338 TUNABLE_QUAD_FETCH("kern.maxmbufmem", &maxmbufmem); 339 if (maxmbufmem > (realmem / 4) * 3) 340 maxmbufmem = (realmem / 4) * 3; 341 342 /* 343 * The default for maxpipekva is min(1/64 of the kernel address space, 344 * max(1/64 of main memory, 512KB)). See sys_pipe.c for more details. 345 */ 346 maxpipekva = (physpages / 64) * PAGE_SIZE; 347 TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva); 348 if (maxpipekva < 512 * 1024) 349 maxpipekva = 512 * 1024; 350 if (maxpipekva > (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 64) 351 maxpipekva = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 352 64; 353 } 354 355 /* 356 * Sysctl stringiying handler for kern.vm_guest. 357 */ 358 static int 359 sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS) 360 { 361 return (SYSCTL_OUT(req, vm_guest_sysctl_names[vm_guest], 362 strlen(vm_guest_sysctl_names[vm_guest]))); 363 } 364