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 pid_t pid_max = PID_MAX; 97 long maxswzone; /* max swmeta KVA storage */ 98 long maxbcache; /* max buffer cache KVA storage */ 99 long maxpipekva; /* Limit on pipe KVA */ 100 int vm_guest; /* Running as virtual machine guest? */ 101 u_long maxtsiz; /* max text size */ 102 u_long dfldsiz; /* initial data size limit */ 103 u_long maxdsiz; /* max data size */ 104 u_long dflssiz; /* initial stack size limit */ 105 u_long maxssiz; /* max stack size */ 106 u_long sgrowsiz; /* amount to grow stack */ 107 108 SYSCTL_INT(_kern, OID_AUTO, hz, CTLFLAG_RDTUN, &hz, 0, 109 "Number of clock ticks per second"); 110 SYSCTL_INT(_kern, OID_AUTO, ncallout, CTLFLAG_RDTUN, &ncallout, 0, 111 "Number of pre-allocated timer events"); 112 SYSCTL_INT(_kern, OID_AUTO, nbuf, CTLFLAG_RDTUN, &nbuf, 0, 113 "Number of buffers in the buffer cache"); 114 SYSCTL_INT(_kern, OID_AUTO, nswbuf, CTLFLAG_RDTUN, &nswbuf, 0, 115 "Number of swap buffers"); 116 SYSCTL_INT(_kern, OID_AUTO, msgbufsize, CTLFLAG_RDTUN, &msgbufsize, 0, 117 "Size of the kernel message buffer"); 118 SYSCTL_LONG(_kern, OID_AUTO, maxswzone, CTLFLAG_RDTUN, &maxswzone, 0, 119 "Maximum memory for swap metadata"); 120 SYSCTL_LONG(_kern, OID_AUTO, maxbcache, CTLFLAG_RDTUN, &maxbcache, 0, 121 "Maximum value of vfs.maxbufspace"); 122 SYSCTL_ULONG(_kern, OID_AUTO, maxtsiz, CTLFLAG_RW | CTLFLAG_TUN, &maxtsiz, 0, 123 "Maximum text size"); 124 SYSCTL_ULONG(_kern, OID_AUTO, dfldsiz, CTLFLAG_RW | CTLFLAG_TUN, &dfldsiz, 0, 125 "Initial data size limit"); 126 SYSCTL_ULONG(_kern, OID_AUTO, maxdsiz, CTLFLAG_RW | CTLFLAG_TUN, &maxdsiz, 0, 127 "Maximum data size"); 128 SYSCTL_ULONG(_kern, OID_AUTO, dflssiz, CTLFLAG_RW | CTLFLAG_TUN, &dflssiz, 0, 129 "Initial stack size limit"); 130 SYSCTL_ULONG(_kern, OID_AUTO, maxssiz, CTLFLAG_RW | CTLFLAG_TUN, &maxssiz, 0, 131 "Maximum stack size"); 132 SYSCTL_ULONG(_kern, OID_AUTO, sgrowsiz, CTLFLAG_RW | CTLFLAG_TUN, &sgrowsiz, 0, 133 "Amount to grow stack on a stack fault"); 134 SYSCTL_PROC(_kern, OID_AUTO, vm_guest, CTLFLAG_RD | CTLTYPE_STRING, 135 NULL, 0, sysctl_kern_vm_guest, "A", 136 "Virtual machine guest detected? (none|generic|xen)"); 137 138 /* 139 * These have to be allocated somewhere; allocating 140 * them here forces loader errors if this file is omitted 141 * (if they've been externed everywhere else; hah!). 142 */ 143 struct buf *swbuf; 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 "none", 151 "generic", 152 "xen", 153 NULL 154 }; 155 156 #ifndef XEN 157 static const char *const vm_bnames[] = { 158 "QEMU", /* QEMU */ 159 "Plex86", /* Plex86 */ 160 "Bochs", /* Bochs */ 161 "Xen", /* Xen */ 162 "BHYVE", /* bhyve */ 163 "Seabios", /* KVM */ 164 NULL 165 }; 166 167 static const char *const vm_pnames[] = { 168 "VMware Virtual Platform", /* VMWare VM */ 169 "Virtual Machine", /* Microsoft VirtualPC */ 170 "VirtualBox", /* Sun xVM VirtualBox */ 171 "Parallels Virtual Platform", /* Parallels VM */ 172 "KVM", /* KVM */ 173 NULL 174 }; 175 176 177 /* 178 * Detect known Virtual Machine hosts by inspecting the emulated BIOS. 179 */ 180 static enum VM_GUEST 181 detect_virtual(void) 182 { 183 char *sysenv; 184 int i; 185 186 sysenv = getenv("smbios.bios.vendor"); 187 if (sysenv != NULL) { 188 for (i = 0; vm_bnames[i] != NULL; i++) 189 if (strcmp(sysenv, vm_bnames[i]) == 0) { 190 freeenv(sysenv); 191 return (VM_GUEST_VM); 192 } 193 freeenv(sysenv); 194 } 195 sysenv = getenv("smbios.system.product"); 196 if (sysenv != NULL) { 197 for (i = 0; vm_pnames[i] != NULL; i++) 198 if (strcmp(sysenv, vm_pnames[i]) == 0) { 199 freeenv(sysenv); 200 return (VM_GUEST_VM); 201 } 202 freeenv(sysenv); 203 } 204 return (VM_GUEST_NO); 205 } 206 #endif 207 208 /* 209 * Boot time overrides that are not scaled against main memory 210 */ 211 void 212 init_param1(void) 213 { 214 #ifndef XEN 215 vm_guest = detect_virtual(); 216 #else 217 vm_guest = VM_GUEST_XEN; 218 #endif 219 hz = -1; 220 TUNABLE_INT_FETCH("kern.hz", &hz); 221 if (hz == -1) 222 hz = vm_guest > VM_GUEST_NO ? HZ_VM : HZ; 223 tick = 1000000 / hz; 224 225 #ifdef VM_SWZONE_SIZE_MAX 226 maxswzone = VM_SWZONE_SIZE_MAX; 227 #endif 228 TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone); 229 #ifdef VM_BCACHE_SIZE_MAX 230 maxbcache = VM_BCACHE_SIZE_MAX; 231 #endif 232 TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache); 233 msgbufsize = MSGBUF_SIZE; 234 TUNABLE_INT_FETCH("kern.msgbufsize", &msgbufsize); 235 236 maxtsiz = MAXTSIZ; 237 TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz); 238 dfldsiz = DFLDSIZ; 239 TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz); 240 maxdsiz = MAXDSIZ; 241 TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz); 242 dflssiz = DFLSSIZ; 243 TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz); 244 maxssiz = MAXSSIZ; 245 TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz); 246 sgrowsiz = SGROWSIZ; 247 TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz); 248 249 /* 250 * Let the administrator set {NGROUPS_MAX}, but disallow values 251 * less than NGROUPS_MAX which would violate POSIX.1-2008 or 252 * greater than INT_MAX-1 which would result in overflow. 253 */ 254 ngroups_max = NGROUPS_MAX; 255 TUNABLE_INT_FETCH("kern.ngroups", &ngroups_max); 256 if (ngroups_max < NGROUPS_MAX) 257 ngroups_max = NGROUPS_MAX; 258 259 /* 260 * Only allow to lower the maximal pid. 261 * Prevent setting up a non-bootable system if pid_max is too low. 262 */ 263 TUNABLE_INT_FETCH("kern.pid_max", &pid_max); 264 if (pid_max > PID_MAX) 265 pid_max = PID_MAX; 266 else if (pid_max < 300) 267 pid_max = 300; 268 } 269 270 /* 271 * Boot time overrides that are scaled against main memory 272 */ 273 void 274 init_param2(long physpages) 275 { 276 277 /* Base parameters */ 278 maxusers = MAXUSERS; 279 TUNABLE_INT_FETCH("kern.maxusers", &maxusers); 280 if (maxusers == 0) { 281 maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE); 282 if (maxusers < 32) 283 maxusers = 32; 284 #ifdef VM_MAX_AUTOTUNE_MAXUSERS 285 if (maxusers > VM_MAX_AUTOTUNE_MAXUSERS) 286 maxusers = VM_MAX_AUTOTUNE_MAXUSERS; 287 #endif 288 /* 289 * Scales down the function in which maxusers grows once 290 * we hit 384. 291 */ 292 if (maxusers > 384) 293 maxusers = 384 + ((maxusers - 384) / 8); 294 } 295 296 /* 297 * The following can be overridden after boot via sysctl. Note: 298 * unless overriden, these macros are ultimately based on maxusers. 299 * Limit maxproc so that kmap entries cannot be exhausted by 300 * processes. 301 */ 302 maxproc = NPROC; 303 TUNABLE_INT_FETCH("kern.maxproc", &maxproc); 304 if (maxproc > (physpages / 12)) 305 maxproc = physpages / 12; 306 maxprocperuid = (maxproc * 9) / 10; 307 308 /* 309 * The default limit for maxfiles is 1/12 of the number of 310 * physical page but not less than 16 times maxusers. 311 * At most it can be 1/6 the number of physical pages. 312 */ 313 maxfiles = imax(MAXFILES, physpages / 8); 314 TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles); 315 if (maxfiles > (physpages / 4)) 316 maxfiles = physpages / 4; 317 maxfilesperproc = (maxfiles / 10) * 9; 318 319 /* 320 * Cannot be changed after boot. 321 */ 322 nbuf = NBUF; 323 TUNABLE_INT_FETCH("kern.nbuf", &nbuf); 324 325 /* 326 * XXX: Does the callout wheel have to be so big? 327 * 328 * Clip callout to result of previous function of maxusers maximum 329 * 384. This is still huge, but acceptable. 330 */ 331 ncallout = imin(16 + maxproc + maxfiles, 18508); 332 TUNABLE_INT_FETCH("kern.ncallout", &ncallout); 333 334 /* 335 * The default for maxpipekva is min(1/64 of the kernel address space, 336 * max(1/64 of main memory, 512KB)). See sys_pipe.c for more details. 337 */ 338 maxpipekva = (physpages / 64) * PAGE_SIZE; 339 TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva); 340 if (maxpipekva < 512 * 1024) 341 maxpipekva = 512 * 1024; 342 if (maxpipekva > (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 64) 343 maxpipekva = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 344 64; 345 } 346 347 /* 348 * Sysctl stringiying handler for kern.vm_guest. 349 */ 350 static int 351 sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS) 352 { 353 return (SYSCTL_OUT(req, vm_guest_sysctl_names[vm_guest], 354 strlen(vm_guest_sysctl_names[vm_guest]))); 355 } 356