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. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)param.c 8.3 (Berkeley) 8/20/94 39 * $FreeBSD: src/sys/kern/subr_param.c,v 1.42.2.10 2002/03/09 21:05:47 silby Exp $ 40 * $DragonFly: src/sys/kern/subr_param.c,v 1.7 2005/06/26 22:03:22 dillon Exp $ 41 */ 42 43 #include "opt_param.h" 44 #include "opt_maxusers.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/kernel.h> 49 #include <sys/malloc.h> 50 #include <vm/pmap.h> 51 #include <machine/vmparam.h> 52 53 /* 54 * System parameter formulae. 55 */ 56 57 #ifndef HZ 58 #define HZ 100 59 #endif 60 #define NPROC (20 + 16 * maxusers) 61 #ifndef NBUF 62 #define NBUF 0 63 #endif 64 #ifndef MAXFILES 65 #define MAXFILES (maxproc * 16) 66 #endif 67 #ifndef MAXPOSIXLOCKSPERUID 68 #define MAXPOSIXLOCKSPERUID (maxusers * 64) /* Should be a safe value */ 69 #endif 70 71 int hz; 72 int stathz; 73 int profhz; 74 int ustick; /* tick interval in microseconds */ 75 int nstick; /* tick interval in nanoseconds */ 76 int maxusers; /* base tunable */ 77 int maxproc; /* maximum # of processes */ 78 int maxprocperuid; /* max # of procs per user */ 79 int maxfiles; /* system wide open files limit */ 80 int maxfilesrootres; /* descriptors reserved for root use */ 81 int minfilesperproc; /* per-proc min open files (safety) */ 82 int maxfilesperproc; /* per-proc open files limit */ 83 int maxfilesperuser; /* per-user open files limit */ 84 int maxposixlocksperuid; /* max # POSIX locks per uid */ 85 int ncallout; /* maximum # of timer events */ 86 int mbuf_wait = 32; /* mbuf sleep time in ticks */ 87 long nbuf; 88 long nswbuf; 89 long maxswzone; /* max swmeta KVA storage */ 90 long maxbcache; /* max buffer cache KVA storage */ 91 int vmm_guest = 0; /* Running as virtual machine guest? */ 92 u_quad_t maxtsiz; /* max text size */ 93 u_quad_t dfldsiz; /* initial data size limit */ 94 u_quad_t maxdsiz; /* max data size */ 95 u_quad_t dflssiz; /* initial stack size limit */ 96 u_quad_t maxssiz; /* max stack size */ 97 u_quad_t sgrowsiz; /* amount to grow stack */ 98 99 /* 100 * These have to be allocated somewhere; allocating 101 * them here forces loader errors if this file is omitted 102 * (if they've been externed everywhere else; hah!). 103 */ 104 struct buf *swbuf; 105 106 /* 107 * Boot time overrides that are not scaled against main memory 108 */ 109 void 110 init_param1(void) 111 { 112 hz = HZ; 113 TUNABLE_INT_FETCH("kern.hz", &hz); 114 stathz = hz * 128 / 100; 115 profhz = stathz; 116 ustick = 1000000 / hz; 117 nstick = 1000000000 / hz; 118 /* can adjust 30ms in 60s */ 119 ntp_default_tick_delta = howmany(30000000, 60 * hz); 120 121 #ifdef VM_SWZONE_SIZE_MAX 122 maxswzone = VM_SWZONE_SIZE_MAX; 123 #endif 124 TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone); 125 #ifdef VM_BCACHE_SIZE_MAX 126 maxbcache = VM_BCACHE_SIZE_MAX; 127 #endif 128 TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache); 129 maxtsiz = MAXTSIZ; 130 TUNABLE_QUAD_FETCH("kern.maxtsiz", &maxtsiz); 131 dfldsiz = DFLDSIZ; 132 TUNABLE_QUAD_FETCH("kern.dfldsiz", &dfldsiz); 133 maxdsiz = MAXDSIZ; 134 TUNABLE_QUAD_FETCH("kern.maxdsiz", &maxdsiz); 135 dflssiz = DFLSSIZ; 136 TUNABLE_QUAD_FETCH("kern.dflssiz", &dflssiz); 137 maxssiz = MAXSSIZ; 138 TUNABLE_QUAD_FETCH("kern.maxssiz", &maxssiz); 139 sgrowsiz = SGROWSIZ; 140 TUNABLE_QUAD_FETCH("kern.sgrowsiz", &sgrowsiz); 141 } 142 143 /* 144 * Boot time overrides that are scaled against main memory 145 */ 146 void 147 init_param2(int physpages) 148 { 149 size_t limsize; 150 151 /* 152 * Calculate manually becaus the VM page queues / system is not set up yet 153 */ 154 limsize = (size_t)physpages * PAGE_SIZE; 155 if (limsize > KvaSize) 156 limsize = KvaSize; 157 limsize /= 1024 * 1024; /* smaller of KVM or physmem in MB */ 158 159 /* Base parameters */ 160 maxusers = MAXUSERS; 161 TUNABLE_INT_FETCH("kern.maxusers", &maxusers); 162 if (maxusers == 0) { 163 maxusers = limsize / 8; /* ~384 per 3G */ 164 if (maxusers < 32) 165 maxusers = 32; 166 /* no upper limit */ 167 } 168 169 /* 170 * The following can be overridden after boot via sysctl. Note: 171 * unless overriden, these macros are ultimately based on maxusers. 172 * 173 * Limit maxproc so that kmap entries cannot be exhausted by 174 * processes. 175 */ 176 maxproc = NPROC; 177 TUNABLE_INT_FETCH("kern.maxproc", &maxproc); 178 if (maxproc < 32) 179 maxproc = 32; 180 if (maxproc > limsize * 21) 181 maxproc = limsize * 21; 182 183 /* 184 * Maximum number of open files 185 */ 186 maxfiles = MAXFILES; 187 TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles); 188 if (maxfiles < 128) 189 maxfiles = 128; 190 191 /* 192 * Limit file descriptors so no single user can exhaust the 193 * system. 194 * 195 * WARNING: Do not set minfilesperproc too high or the user 196 * can exhaust the system with a combination of fork() 197 * and open(). Actual worst case is: 198 * 199 * (minfilesperproc * maxprocperuid) + maxfilesperuser 200 */ 201 maxprocperuid = maxproc / 4; 202 if (maxprocperuid < 128) 203 maxprocperuid = maxproc / 2; 204 minfilesperproc = 8; 205 maxfilesperproc = maxfiles / 4; 206 maxfilesperuser = maxfilesperproc * 2; 207 maxfilesrootres = maxfiles / 20; 208 209 /* 210 * Severe hack to try to prevent pipe() descriptors from 211 * blowing away kernel memory. 212 */ 213 if (KvaSize <= (vm_offset_t)(1536LL * 1024 * 1024) && 214 maxfilesperuser > 20000) { 215 maxfilesperuser = 20000; 216 } 217 218 maxposixlocksperuid = MAXPOSIXLOCKSPERUID; 219 TUNABLE_INT_FETCH("kern.maxposixlocksperuid", &maxposixlocksperuid); 220 221 /* 222 * Unless overriden, NBUF is typically 0 (auto-sized later). 223 */ 224 nbuf = NBUF; 225 TUNABLE_LONG_FETCH("kern.nbuf", &nbuf); 226 227 ncallout = 16 + maxproc + maxfiles; 228 TUNABLE_INT_FETCH("kern.ncallout", &ncallout); 229 } 230 231