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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/limits.h>
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/kernel.h>
47 #include <sys/sysctl.h>
49 #include <vm/vm_param.h>
52 * System parameter formulae.
56 # if defined(__amd64__) || defined(__i386__) || defined(__ia64__) || defined(__sparc64__)
69 #define NPROC (20 + 16 * maxusers)
74 #define MAXFILES (maxproc * 2)
77 static int sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS);
81 int maxusers; /* base tunable */
82 int maxproc; /* maximum # of processes */
83 int maxprocperuid; /* max # of procs per user */
84 int maxfiles; /* sys. wide open files limit */
85 int maxfilesperproc; /* per-proc open files limit */
86 int ncallout; /* maximum # of timer events */
88 int ngroups_max; /* max # groups per process */
90 long maxswzone; /* max swmeta KVA storage */
91 long maxbcache; /* max buffer cache KVA storage */
92 long maxpipekva; /* Limit on pipe KVA */
93 int vm_guest; /* Running as virtual machine guest? */
94 u_long maxtsiz; /* max text size */
95 u_long dfldsiz; /* initial data size limit */
96 u_long maxdsiz; /* max data size */
97 u_long dflssiz; /* initial stack size limit */
98 u_long maxssiz; /* max stack size */
99 u_long sgrowsiz; /* amount to grow stack */
101 SYSCTL_INT(_kern, OID_AUTO, hz, CTLFLAG_RDTUN, &hz, 0,
102 "Number of clock ticks per second");
103 SYSCTL_INT(_kern, OID_AUTO, ncallout, CTLFLAG_RDTUN, &ncallout, 0,
104 "Number of pre-allocated timer events");
105 SYSCTL_INT(_kern, OID_AUTO, nbuf, CTLFLAG_RDTUN, &nbuf, 0,
106 "Number of buffers in the buffer cache");
107 SYSCTL_INT(_kern, OID_AUTO, nswbuf, CTLFLAG_RDTUN, &nswbuf, 0,
108 "Number of swap buffers");
109 SYSCTL_LONG(_kern, OID_AUTO, maxswzone, CTLFLAG_RDTUN, &maxswzone, 0,
110 "Maximum memory for swap metadata");
111 SYSCTL_LONG(_kern, OID_AUTO, maxbcache, CTLFLAG_RDTUN, &maxbcache, 0,
112 "Maximum value of vfs.maxbufspace");
113 SYSCTL_ULONG(_kern, OID_AUTO, maxtsiz, CTLFLAG_RDTUN, &maxtsiz, 0,
114 "Maximum text size");
115 SYSCTL_ULONG(_kern, OID_AUTO, dfldsiz, CTLFLAG_RDTUN, &dfldsiz, 0,
116 "Initial data size limit");
117 SYSCTL_ULONG(_kern, OID_AUTO, maxdsiz, CTLFLAG_RDTUN, &maxdsiz, 0,
118 "Maximum data size");
119 SYSCTL_ULONG(_kern, OID_AUTO, dflssiz, CTLFLAG_RDTUN, &dflssiz, 0,
120 "Initial stack size limit");
121 SYSCTL_ULONG(_kern, OID_AUTO, maxssiz, CTLFLAG_RDTUN, &maxssiz, 0,
122 "Maximum stack size");
123 SYSCTL_ULONG(_kern, OID_AUTO, sgrowsiz, CTLFLAG_RDTUN, &sgrowsiz, 0,
124 "Amount to grow stack on a stack fault");
125 SYSCTL_PROC(_kern, OID_AUTO, vm_guest, CTLFLAG_RD | CTLTYPE_STRING,
126 NULL, 0, sysctl_kern_vm_guest, "A",
127 "Virtual machine guest detected? (none|generic|xen)");
130 * These have to be allocated somewhere; allocating
131 * them here forces loader errors if this file is omitted
132 * (if they've been externed everywhere else; hah!).
137 * The elements of this array are ordered based upon the values of the
138 * corresponding enum VM_GUEST members.
140 static const char *const vm_guest_sysctl_names[] = {
148 static const char *const vm_bnames[] = {
150 "Plex86", /* Plex86 */
155 static const char *const vm_pnames[] = {
156 "VMware Virtual Platform", /* VMWare VM */
157 "Virtual Machine", /* Microsoft VirtualPC */
158 "VirtualBox", /* Sun xVM VirtualBox */
159 "Parallels Virtual Platform", /* Parallels VM */
165 * Detect known Virtual Machine hosts by inspecting the emulated BIOS.
173 sysenv = getenv("smbios.bios.vendor");
174 if (sysenv != NULL) {
175 for (i = 0; vm_bnames[i] != NULL; i++)
176 if (strcmp(sysenv, vm_bnames[i]) == 0) {
178 return (VM_GUEST_VM);
182 sysenv = getenv("smbios.system.product");
183 if (sysenv != NULL) {
184 for (i = 0; vm_pnames[i] != NULL; i++)
185 if (strcmp(sysenv, vm_pnames[i]) == 0) {
187 return (VM_GUEST_VM);
191 return (VM_GUEST_NO);
196 * Boot time overrides that are not scaled against main memory
202 vm_guest = detect_virtual();
204 vm_guest = VM_GUEST_XEN;
207 TUNABLE_INT_FETCH("kern.hz", &hz);
209 hz = vm_guest > VM_GUEST_NO ? HZ_VM : HZ;
212 #ifdef VM_SWZONE_SIZE_MAX
213 maxswzone = VM_SWZONE_SIZE_MAX;
215 TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone);
216 #ifdef VM_BCACHE_SIZE_MAX
217 maxbcache = VM_BCACHE_SIZE_MAX;
219 TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache);
222 TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz);
224 TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz);
226 TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz);
228 TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz);
230 TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz);
232 TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz);
235 * Let the administrator set {NGROUPS_MAX}, but disallow values
236 * less than NGROUPS_MAX which would violate POSIX.1-2008 or
237 * greater than INT_MAX-1 which would result in overflow.
239 ngroups_max = NGROUPS_MAX;
240 TUNABLE_INT_FETCH("kern.ngroups", &ngroups_max);
241 if (ngroups_max < NGROUPS_MAX)
242 ngroups_max = NGROUPS_MAX;
246 * Boot time overrides that are scaled against main memory
249 init_param2(long physpages)
252 /* Base parameters */
254 TUNABLE_INT_FETCH("kern.maxusers", &maxusers);
256 maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE);
264 * The following can be overridden after boot via sysctl. Note:
265 * unless overriden, these macros are ultimately based on maxusers.
268 TUNABLE_INT_FETCH("kern.maxproc", &maxproc);
270 * Limit maxproc so that kmap entries cannot be exhausted by
273 if (maxproc > (physpages / 12))
274 maxproc = physpages / 12;
276 TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles);
277 maxprocperuid = (maxproc * 9) / 10;
278 maxfilesperproc = (maxfiles * 9) / 10;
281 * Cannot be changed after boot.
284 TUNABLE_INT_FETCH("kern.nbuf", &nbuf);
286 ncallout = 16 + maxproc + maxfiles;
287 TUNABLE_INT_FETCH("kern.ncallout", &ncallout);
291 * Boot time overrides that are scaled against the kmem map
294 init_param3(long kmempages)
298 * The default for maxpipekva is max(5% of the kmem map, 512KB).
299 * See sys_pipe.c for more details.
301 maxpipekva = (kmempages / 20) * PAGE_SIZE;
302 if (maxpipekva < 512 * 1024)
303 maxpipekva = 512 * 1024;
304 TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva);
308 * Sysctl stringiying handler for kern.vm_guest.
311 sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS)
313 return (SYSCTL_OUT(req, vm_guest_sysctl_names[vm_guest],
314 strlen(vm_guest_sysctl_names[vm_guest])));