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 <vm/pmap.h> 50 #include <machine/vmparam.h> 51 52 /* 53 * System parameter formulae. 54 */ 55 56 #ifndef HZ 57 #define HZ 100 58 #endif 59 #define NPROC (20 + 16 * maxusers) 60 #ifndef NBUF 61 #define NBUF 0 62 #endif 63 #ifndef MAXFILES 64 #define MAXFILES (maxproc * 16) 65 #endif 66 #ifndef MAXPOSIXLOCKSPERUID 67 #define MAXPOSIXLOCKSPERUID (maxusers * 64) /* Should be a safe value */ 68 #endif 69 70 int hz; 71 int stathz; 72 int profhz; 73 int ustick; /* tick interval in microseconds */ 74 int nstick; /* tick interval in nanoseconds */ 75 int maxusers; /* base tunable */ 76 int maxproc; /* maximum # of processes */ 77 int maxprocperuid; /* max # of procs per user */ 78 int maxfiles; /* system wide open files limit */ 79 int maxfilesrootres; /* descriptors reserved for root use */ 80 int minfilesperproc; /* per-proc min open files (safety) */ 81 int maxfilesperproc; /* per-proc open files limit */ 82 int maxfilesperuser; /* per-user open files limit */ 83 int maxposixlocksperuid; /* max # POSIX locks per uid */ 84 int ncallout; /* maximum # of timer events */ 85 int mbuf_wait = 32; /* mbuf sleep time in ticks */ 86 int nbuf; 87 int nswbuf; 88 long maxswzone; /* max swmeta KVA storage */ 89 long maxbcache; /* max buffer cache KVA storage */ 90 u_quad_t maxtsiz; /* max text size */ 91 u_quad_t dfldsiz; /* initial data size limit */ 92 u_quad_t maxdsiz; /* max data size */ 93 u_quad_t dflssiz; /* initial stack size limit */ 94 u_quad_t maxssiz; /* max stack size */ 95 u_quad_t sgrowsiz; /* amount to grow stack */ 96 97 /* 98 * These have to be allocated somewhere; allocating 99 * them here forces loader errors if this file is omitted 100 * (if they've been externed everywhere else; hah!). 101 */ 102 struct buf *swbuf; 103 104 /* 105 * Boot time overrides that are not scaled against main memory 106 */ 107 void 108 init_param1(void) 109 { 110 hz = HZ; 111 TUNABLE_INT_FETCH("kern.hz", &hz); 112 stathz = hz * 128 / 100; 113 profhz = stathz; 114 ustick = 1000000 / hz; 115 nstick = 1000000000 / hz; 116 /* can adjust 30ms in 60s */ 117 ntp_default_tick_delta = howmany(30000000, 60 * hz); 118 119 #ifdef VM_SWZONE_SIZE_MAX 120 maxswzone = VM_SWZONE_SIZE_MAX; 121 #endif 122 TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone); 123 #ifdef VM_BCACHE_SIZE_MAX 124 maxbcache = VM_BCACHE_SIZE_MAX; 125 #endif 126 TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache); 127 maxtsiz = MAXTSIZ; 128 TUNABLE_QUAD_FETCH("kern.maxtsiz", &maxtsiz); 129 dfldsiz = DFLDSIZ; 130 TUNABLE_QUAD_FETCH("kern.dfldsiz", &dfldsiz); 131 maxdsiz = MAXDSIZ; 132 TUNABLE_QUAD_FETCH("kern.maxdsiz", &maxdsiz); 133 dflssiz = DFLSSIZ; 134 TUNABLE_QUAD_FETCH("kern.dflssiz", &dflssiz); 135 maxssiz = MAXSSIZ; 136 TUNABLE_QUAD_FETCH("kern.maxssiz", &maxssiz); 137 sgrowsiz = SGROWSIZ; 138 TUNABLE_QUAD_FETCH("kern.sgrowsiz", &sgrowsiz); 139 } 140 141 /* 142 * Boot time overrides that are scaled against main memory 143 */ 144 void 145 init_param2(int physpages) 146 { 147 148 /* Base parameters */ 149 maxusers = MAXUSERS; 150 TUNABLE_INT_FETCH("kern.maxusers", &maxusers); 151 if (maxusers == 0) { 152 maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE); 153 if (maxusers < 32) 154 maxusers = 32; 155 if (maxusers > 384) 156 maxusers = 384; 157 } 158 159 /* 160 * The following can be overridden after boot via sysctl. Note: 161 * unless overriden, these macros are ultimately based on maxusers. 162 */ 163 maxproc = NPROC; 164 TUNABLE_INT_FETCH("kern.maxproc", &maxproc); 165 166 /* 167 * Limit maxproc so that kmap entries cannot be exhausted by 168 * processes. 169 */ 170 if (maxproc > (physpages / 12)) 171 maxproc = physpages / 12; 172 maxfiles = MAXFILES; 173 TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles); 174 if (maxfiles < 128) 175 maxfiles = 128; 176 177 /* 178 * Limit file descriptors so no single user can exhaust the 179 * system. 180 * 181 * WARNING: Do not set minfilesperproc too high or the user 182 * can exhaust the system with a combination of fork() 183 * and open(). Actual worst case is: 184 * 185 * (minfilesperproc * maxprocperuid) + maxfilesperuser 186 */ 187 maxprocperuid = maxproc / 4; 188 if (maxprocperuid < 128) 189 maxprocperuid = maxproc / 2; 190 minfilesperproc = 8; 191 maxfilesperproc = maxfiles / 4; 192 maxfilesperuser = maxfilesperproc * 2; 193 maxfilesrootres = maxfiles / 20; 194 195 /* 196 * Severe hack to try to prevent pipe() descriptors from 197 * blowing away kernel memory. 198 */ 199 if (KvaSize <= (vm_offset_t)(1536LL * 1024 * 1024) && 200 maxfilesperuser > 20000) { 201 maxfilesperuser = 20000; 202 } 203 204 maxposixlocksperuid = MAXPOSIXLOCKSPERUID; 205 TUNABLE_INT_FETCH("kern.maxposixlocksperuid", &maxposixlocksperuid); 206 207 /* 208 * Unless overriden, NBUF is typically 0 (auto-sized later). 209 */ 210 nbuf = NBUF; 211 TUNABLE_INT_FETCH("kern.nbuf", &nbuf); 212 213 ncallout = 16 + maxproc + maxfiles; 214 TUNABLE_INT_FETCH("kern.ncallout", &ncallout); 215 } 216 217