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34 * @(#)param.c 8.3 (Berkeley) 8/20/94
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
40 #include "opt_param.h"
41 #include "opt_maxusers.h"
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/kernel.h>
46 #include <sys/sysctl.h>
48 #include <vm/vm_param.h>
51 * System parameter formulae.
55 # if defined(__amd64__) || defined(__i386__) || defined(__ia64__) || defined(__sparc64__)
61 #define NPROC (20 + 16 * maxusers)
66 #define MAXFILES (maxproc * 2)
71 int maxusers; /* base tunable */
72 int maxproc; /* maximum # of processes */
73 int maxprocperuid; /* max # of procs per user */
74 int maxfiles; /* sys. wide open files limit */
75 int maxfilesperproc; /* per-proc open files limit */
76 int ncallout; /* maximum # of timer events */
79 int maxswzone; /* max swmeta KVA storage */
80 int maxbcache; /* max buffer cache KVA storage */
81 int maxpipekva; /* Limit on pipe KVA */
82 u_long maxtsiz; /* max text size */
83 u_long dfldsiz; /* initial data size limit */
84 u_long maxdsiz; /* max data size */
85 u_long dflssiz; /* initial stack size limit */
86 u_long maxssiz; /* max stack size */
87 u_long sgrowsiz; /* amount to grow stack */
89 SYSCTL_INT(_kern, OID_AUTO, maxswzone, CTLFLAG_RD, &maxswzone, 0, "");
90 SYSCTL_INT(_kern, OID_AUTO, maxbcache, CTLFLAG_RD, &maxbcache, 0, "");
91 SYSCTL_ULONG(_kern, OID_AUTO, maxtsiz, CTLFLAG_RD, &maxtsiz, 0, "");
92 SYSCTL_ULONG(_kern, OID_AUTO, dfldsiz, CTLFLAG_RD, &dfldsiz, 0, "");
93 SYSCTL_ULONG(_kern, OID_AUTO, maxdsiz, CTLFLAG_RD, &maxdsiz, 0, "");
94 SYSCTL_ULONG(_kern, OID_AUTO, dflssiz, CTLFLAG_RD, &dflssiz, 0, "");
95 SYSCTL_ULONG(_kern, OID_AUTO, maxssiz, CTLFLAG_RD, &maxssiz, 0, "");
96 SYSCTL_ULONG(_kern, OID_AUTO, sgrowsiz, CTLFLAG_RD, &sgrowsiz, 0, "");
99 * These have to be allocated somewhere; allocating
100 * them here forces loader errors if this file is omitted
101 * (if they've been externed everywhere else; hah!).
106 * Boot time overrides that are not scaled against main memory
113 TUNABLE_INT_FETCH("kern.hz", &hz);
116 #ifdef VM_SWZONE_SIZE_MAX
117 maxswzone = VM_SWZONE_SIZE_MAX;
119 TUNABLE_INT_FETCH("kern.maxswzone", &maxswzone);
120 #ifdef VM_BCACHE_SIZE_MAX
121 maxbcache = VM_BCACHE_SIZE_MAX;
123 TUNABLE_INT_FETCH("kern.maxbcache", &maxbcache);
126 TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz);
128 TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz);
130 TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz);
132 TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz);
134 TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz);
136 TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz);
140 * Boot time overrides that are scaled against main memory
143 init_param2(long physpages)
146 /* Base parameters */
148 TUNABLE_INT_FETCH("kern.maxusers", &maxusers);
150 maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE);
158 * The following can be overridden after boot via sysctl. Note:
159 * unless overriden, these macros are ultimately based on maxusers.
162 TUNABLE_INT_FETCH("kern.maxproc", &maxproc);
164 * Limit maxproc so that kmap entries cannot be exhausted by
167 if (maxproc > (physpages / 12))
168 maxproc = physpages / 12;
170 TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles);
171 maxprocperuid = (maxproc * 9) / 10;
172 maxfilesperproc = (maxfiles * 9) / 10;
175 * Cannot be changed after boot.
178 TUNABLE_INT_FETCH("kern.nbuf", &nbuf);
180 ncallout = 16 + maxproc + maxfiles;
181 TUNABLE_INT_FETCH("kern.ncallout", &ncallout);
185 * Boot time overrides that are scaled against the kernel map
188 init_param3(long kmempages)
192 * The default for maxpipekva is max(5% of the kernel map, 512KB).
193 * See sys_pipe.c for more details.
195 maxpipekva = (kmempages / 20) * PAGE_SIZE;
196 if (maxpipekva < 512 * 1024)
197 maxpipekva = 512 * 1024;
198 TUNABLE_INT_FETCH("kern.ipc.maxpipekva", &maxpipekva);