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38 * @(#)param.c 8.3 (Berkeley) 8/20/94
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
44 #include "opt_param.h"
45 #include "opt_maxusers.h"
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/kernel.h>
51 #include <machine/vmparam.h>
54 * System parameter formulae.
60 #define NPROC (20 + 16 * maxusers)
65 #define MAXFILES (maxproc * 2)
70 int maxusers; /* base tunable */
71 int maxproc; /* maximum # of processes */
72 int maxprocperuid; /* max # of procs per user */
73 int maxfiles; /* sys. wide open files limit */
74 int maxfilesperproc; /* per-proc open files limit */
75 int ncallout; /* maximum # of timer events */
78 int maxswzone; /* max swmeta KVA storage */
79 int maxbcache; /* max buffer cache KVA storage */
80 int maxpipekva; /* Limit on pipe KVA */
81 int maxpipekvawired; /* Limit on wired pipe KVA */
82 u_quad_t maxtsiz; /* max text size */
83 u_quad_t dfldsiz; /* initial data size limit */
84 u_quad_t maxdsiz; /* max data size */
85 u_quad_t dflssiz; /* initial stack size limit */
86 u_quad_t maxssiz; /* max stack size */
87 u_quad_t sgrowsiz; /* amount to grow stack */
90 * These have to be allocated somewhere; allocating
91 * them here forces loader errors if this file is omitted
92 * (if they've been externed everywhere else; hah!).
97 * Boot time overrides that are not scaled against main memory
104 TUNABLE_INT_FETCH("kern.hz", &hz);
107 #ifdef VM_SWZONE_SIZE_MAX
108 maxswzone = VM_SWZONE_SIZE_MAX;
110 TUNABLE_INT_FETCH("kern.maxswzone", &maxswzone);
111 #ifdef VM_BCACHE_SIZE_MAX
112 maxbcache = VM_BCACHE_SIZE_MAX;
114 TUNABLE_INT_FETCH("kern.maxbcache", &maxbcache);
117 TUNABLE_QUAD_FETCH("kern.maxtsiz", &maxtsiz);
119 TUNABLE_QUAD_FETCH("kern.dfldsiz", &dfldsiz);
121 TUNABLE_QUAD_FETCH("kern.maxdsiz", &maxdsiz);
123 TUNABLE_QUAD_FETCH("kern.dflssiz", &dflssiz);
125 TUNABLE_QUAD_FETCH("kern.maxssiz", &maxssiz);
127 TUNABLE_QUAD_FETCH("kern.sgrowsiz", &sgrowsiz);
131 * Boot time overrides that are scaled against main memory
134 init_param2(long physpages)
137 /* Base parameters */
139 TUNABLE_INT_FETCH("kern.maxusers", &maxusers);
141 maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE);
149 * The following can be overridden after boot via sysctl. Note:
150 * unless overriden, these macros are ultimately based on maxusers.
153 TUNABLE_INT_FETCH("kern.maxproc", &maxproc);
155 * Limit maxproc so that kmap entries cannot be exhausted by
158 if (maxproc > (physpages / 12))
159 maxproc = physpages / 12;
161 TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles);
162 maxprocperuid = (maxproc * 9) / 10;
163 maxfilesperproc = (maxfiles * 9) / 10;
166 * Cannot be changed after boot.
169 TUNABLE_INT_FETCH("kern.nbuf", &nbuf);
171 ncallout = 16 + maxproc + maxfiles;
172 TUNABLE_INT_FETCH("kern.ncallout", &ncallout);
176 * Boot time overrides that are scaled against the kernel map
179 init_param3(long kmempages)
182 * Limit pageable pipe memory usage to 5% of the kernel map
183 * (via pipe_map), and nonpageable pipe memory usage to 2.5%
184 * of the same. Ensure that all have reasonable floors.
185 * (See sys_pipe.c for more info.)
187 maxpipekva = (kmempages / 20) * PAGE_SIZE;
188 maxpipekvawired = (kmempages / 40) * PAGE_SIZE;
190 if (maxpipekva < 512 * 1024)
191 maxpipekva = 512 * 1024;
192 if (maxpipekvawired < 512 * 1024)
193 maxpipekvawired = 512 * 1024;
195 TUNABLE_INT_FETCH("kern.ipc.maxpipekva", &maxpipekva);