The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/kern/subr_param.c

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    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: releng/8.3/sys/kern/subr_param.c 219662 2011-03-15 08:20:59Z pluknet $");
   39 
   40 #include "opt_param.h"
   41 #include "opt_msgbuf.h"
   42 #include "opt_maxusers.h"
   43 
   44 #include <sys/limits.h>
   45 #include <sys/param.h>
   46 #include <sys/systm.h>
   47 #include <sys/kernel.h>
   48 #include <sys/sysctl.h>
   49 #include <sys/msgbuf.h>
   50 
   51 #include <vm/vm_param.h>
   52 
   53 /*
   54  * System parameter formulae.
   55  */
   56 
   57 #ifndef HZ
   58 #  if defined(__mips__) || defined(__arm__)
   59 #    define     HZ 100
   60 #  else
   61 #    define     HZ 1000
   62 #  endif
   63 #  ifndef HZ_VM
   64 #    define     HZ_VM 100
   65 #  endif
   66 #else
   67 #  ifndef HZ_VM
   68 #    define     HZ_VM HZ
   69 #  endif
   70 #endif
   71 #define NPROC (20 + 16 * maxusers)
   72 #ifndef NBUF
   73 #define NBUF 0
   74 #endif
   75 #ifndef MAXFILES
   76 #define MAXFILES (maxproc * 2)
   77 #endif
   78 
   79 static int sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS);
   80 
   81 int     hz;
   82 int     tick;
   83 int     maxusers;                       /* base tunable */
   84 int     maxproc;                        /* maximum # of processes */
   85 int     maxprocperuid;                  /* max # of procs per user */
   86 int     maxfiles;                       /* sys. wide open files limit */
   87 int     maxfilesperproc;                /* per-proc open files limit */
   88 int     msgbufsize;                     /* size of kernel message buffer */
   89 int     ncallout;                       /* maximum # of timer events */
   90 int     nbuf;
   91 int     ngroups_max;                    /* max # groups per process */
   92 int     nswbuf;
   93 long    maxswzone;                      /* max swmeta KVA storage */
   94 long    maxbcache;                      /* max buffer cache KVA storage */
   95 long    maxpipekva;                     /* Limit on pipe KVA */
   96 int     vm_guest;                       /* Running as virtual machine guest? */
   97 u_long  maxtsiz;                        /* max text size */
   98 u_long  dfldsiz;                        /* initial data size limit */
   99 u_long  maxdsiz;                        /* max data size */
  100 u_long  dflssiz;                        /* initial stack size limit */
  101 u_long  maxssiz;                        /* max stack size */
  102 u_long  sgrowsiz;                       /* amount to grow stack */
  103 
  104 SYSCTL_INT(_kern, OID_AUTO, hz, CTLFLAG_RDTUN, &hz, 0,
  105     "Number of clock ticks per second");
  106 SYSCTL_INT(_kern, OID_AUTO, ncallout, CTLFLAG_RDTUN, &ncallout, 0,
  107     "Number of pre-allocated timer events");
  108 SYSCTL_INT(_kern, OID_AUTO, nbuf, CTLFLAG_RDTUN, &nbuf, 0,
  109     "Number of buffers in the buffer cache");
  110 SYSCTL_INT(_kern, OID_AUTO, nswbuf, CTLFLAG_RDTUN, &nswbuf, 0,
  111     "Number of swap buffers");
  112 SYSCTL_INT(_kern, OID_AUTO, msgbufsize, CTLFLAG_RDTUN, &msgbufsize, 0,
  113     "Size of the kernel message buffer");
  114 SYSCTL_LONG(_kern, OID_AUTO, maxswzone, CTLFLAG_RDTUN, &maxswzone, 0,
  115     "Maximum memory for swap metadata");
  116 SYSCTL_LONG(_kern, OID_AUTO, maxbcache, CTLFLAG_RDTUN, &maxbcache, 0,
  117     "Maximum value of vfs.maxbufspace");
  118 SYSCTL_ULONG(_kern, OID_AUTO, maxtsiz, CTLFLAG_RDTUN, &maxtsiz, 0,
  119     "Maximum text size");
  120 SYSCTL_ULONG(_kern, OID_AUTO, dfldsiz, CTLFLAG_RDTUN, &dfldsiz, 0,
  121     "Initial data size limit");
  122 SYSCTL_ULONG(_kern, OID_AUTO, maxdsiz, CTLFLAG_RDTUN, &maxdsiz, 0,
  123     "Maximum data size");
  124 SYSCTL_ULONG(_kern, OID_AUTO, dflssiz, CTLFLAG_RDTUN, &dflssiz, 0,
  125     "Initial stack size limit");
  126 SYSCTL_ULONG(_kern, OID_AUTO, maxssiz, CTLFLAG_RDTUN, &maxssiz, 0,
  127     "Maximum stack size");
  128 SYSCTL_ULONG(_kern, OID_AUTO, sgrowsiz, CTLFLAG_RDTUN, &sgrowsiz, 0,
  129     "Amount to grow stack on a stack fault");
  130 SYSCTL_PROC(_kern, OID_AUTO, vm_guest, CTLFLAG_RD | CTLTYPE_STRING,
  131     NULL, 0, sysctl_kern_vm_guest, "A",
  132     "Virtual machine guest detected? (none|generic|xen)");
  133 
  134 /*
  135  * These have to be allocated somewhere; allocating
  136  * them here forces loader errors if this file is omitted
  137  * (if they've been externed everywhere else; hah!).
  138  */
  139 struct  buf *swbuf;
  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         NULL
  150 };
  151 
  152 #ifndef XEN
  153 static const char *const vm_bnames[] = {
  154         "QEMU",                         /* QEMU */
  155         "Plex86",                       /* Plex86 */
  156         "Bochs",                        /* Bochs */
  157         "Xen",                          /* Xen */
  158         NULL
  159 };
  160 
  161 static const char *const vm_pnames[] = {
  162         "VMware Virtual Platform",      /* VMWare VM */
  163         "Virtual Machine",              /* Microsoft VirtualPC */
  164         "VirtualBox",                   /* Sun xVM VirtualBox */
  165         "Parallels Virtual Platform",   /* Parallels VM */
  166         NULL
  167 };
  168 
  169 
  170 /*
  171  * Detect known Virtual Machine hosts by inspecting the emulated BIOS.
  172  */
  173 static enum VM_GUEST
  174 detect_virtual(void)
  175 {
  176         char *sysenv;
  177         int i;
  178 
  179         sysenv = getenv("smbios.bios.vendor");
  180         if (sysenv != NULL) {
  181                 for (i = 0; vm_bnames[i] != NULL; i++)
  182                         if (strcmp(sysenv, vm_bnames[i]) == 0) {
  183                                 freeenv(sysenv);
  184                                 return (VM_GUEST_VM);
  185                         }
  186                 freeenv(sysenv);
  187         }
  188         sysenv = getenv("smbios.system.product");
  189         if (sysenv != NULL) {
  190                 for (i = 0; vm_pnames[i] != NULL; i++)
  191                         if (strcmp(sysenv, vm_pnames[i]) == 0) {
  192                                 freeenv(sysenv);
  193                                 return (VM_GUEST_VM);
  194                         }
  195                 freeenv(sysenv);
  196         }
  197         return (VM_GUEST_NO);
  198 }
  199 #endif
  200 
  201 /*
  202  * Boot time overrides that are not scaled against main memory
  203  */
  204 void
  205 init_param1(void)
  206 {
  207 #ifndef XEN
  208         vm_guest = detect_virtual();
  209 #else
  210         vm_guest = VM_GUEST_XEN;
  211 #endif
  212         hz = -1;
  213         TUNABLE_INT_FETCH("kern.hz", &hz);
  214         if (hz == -1)
  215                 hz = vm_guest > VM_GUEST_NO ? HZ_VM : HZ;
  216         tick = 1000000 / hz;
  217 
  218 #ifdef VM_SWZONE_SIZE_MAX
  219         maxswzone = VM_SWZONE_SIZE_MAX;
  220 #endif
  221         TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone);
  222 #ifdef VM_BCACHE_SIZE_MAX
  223         maxbcache = VM_BCACHE_SIZE_MAX;
  224 #endif
  225         TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache);
  226         msgbufsize = MSGBUF_SIZE;
  227         TUNABLE_INT_FETCH("kern.msgbufsize", &msgbufsize);
  228 
  229         maxtsiz = MAXTSIZ;
  230         TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz);
  231         dfldsiz = DFLDSIZ;
  232         TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz);
  233         maxdsiz = MAXDSIZ;
  234         TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz);
  235         dflssiz = DFLSSIZ;
  236         TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz);
  237         maxssiz = MAXSSIZ;
  238         TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz);
  239         sgrowsiz = SGROWSIZ;
  240         TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz);
  241 
  242         /*
  243          * Let the administrator set {NGROUPS_MAX}, but disallow values
  244          * less than NGROUPS_MAX which would violate POSIX.1-2008 or
  245          * greater than INT_MAX-1 which would result in overflow.
  246          */
  247         ngroups_max = NGROUPS_MAX;
  248         TUNABLE_INT_FETCH("kern.ngroups", &ngroups_max);
  249         if (ngroups_max < NGROUPS_MAX)
  250                 ngroups_max = NGROUPS_MAX;
  251 }
  252 
  253 /*
  254  * Boot time overrides that are scaled against main memory
  255  */
  256 void
  257 init_param2(long physpages)
  258 {
  259 
  260         /* Base parameters */
  261         maxusers = MAXUSERS;
  262         TUNABLE_INT_FETCH("kern.maxusers", &maxusers);
  263         if (maxusers == 0) {
  264                 maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE);
  265                 if (maxusers < 32)
  266                         maxusers = 32;
  267                 if (maxusers > 384)
  268                         maxusers = 384;
  269         }
  270 
  271         /*
  272          * The following can be overridden after boot via sysctl.  Note:
  273          * unless overriden, these macros are ultimately based on maxusers.
  274          */
  275         maxproc = NPROC;
  276         TUNABLE_INT_FETCH("kern.maxproc", &maxproc);
  277         /*
  278          * Limit maxproc so that kmap entries cannot be exhausted by
  279          * processes.
  280          */
  281         if (maxproc > (physpages / 12))
  282                 maxproc = physpages / 12;
  283         maxfiles = MAXFILES;
  284         TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles);
  285         maxprocperuid = (maxproc * 9) / 10;
  286         maxfilesperproc = (maxfiles * 9) / 10;
  287         
  288         /*
  289          * Cannot be changed after boot.
  290          */
  291         nbuf = NBUF;
  292         TUNABLE_INT_FETCH("kern.nbuf", &nbuf);
  293 
  294         ncallout = 16 + maxproc + maxfiles;
  295         TUNABLE_INT_FETCH("kern.ncallout", &ncallout);
  296 }
  297 
  298 /*
  299  * Boot time overrides that are scaled against the kmem map
  300  */
  301 void
  302 init_param3(long kmempages)
  303 {
  304 
  305         /*
  306          * The default for maxpipekva is max(5% of the kmem map, 512KB).
  307          * See sys_pipe.c for more details.
  308          */
  309         maxpipekva = (kmempages / 20) * PAGE_SIZE;
  310         if (maxpipekva < 512 * 1024)
  311                 maxpipekva = 512 * 1024;
  312         TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva);
  313 }
  314 
  315 /*
  316  * Sysctl stringiying handler for kern.vm_guest.
  317  */
  318 static int
  319 sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS)
  320 {
  321         return (SYSCTL_OUT(req, vm_guest_sysctl_names[vm_guest], 
  322             strlen(vm_guest_sysctl_names[vm_guest])));
  323 }

Cache object: 35290cd7eea753f9b5b190019f2039c2


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.