1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1980, 1986, 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37 #include <sys/cdefs.h>
38 #include "opt_param.h"
39 #include "opt_msgbuf.h"
40 #include "opt_maxphys.h"
41 #include "opt_maxusers.h"
42
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/buf.h>
46 #include <sys/kernel.h>
47 #include <sys/limits.h>
48 #include <sys/msgbuf.h>
49 #include <sys/sysctl.h>
50 #include <sys/proc.h>
51 #include <sys/vnode.h>
52
53 #include <vm/vm.h>
54 #include <vm/vm_param.h>
55 #include <vm/pmap.h>
56
57 /*
58 * System parameter formulae.
59 */
60
61 #ifndef HZ
62 # define HZ 1000
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 (40 + 32 * maxusers)
77 #endif
78
79 static int sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS);
80
81 int hz; /* system clock's frequency */
82 int tick; /* usec per tick (1000000 / hz) */
83 time_t tick_seconds_max; /* max hz * seconds an integer can hold */
84 struct bintime tick_bt; /* bintime per tick (1s / hz) */
85 sbintime_t tick_sbt;
86 int maxusers; /* base tunable */
87 int maxproc; /* maximum # of processes */
88 int maxprocperuid; /* max # of procs per user */
89 int maxfiles; /* sys. wide open files limit */
90 int maxfilesperproc; /* per-proc open files limit */
91 int msgbufsize; /* size of kernel message buffer */
92 int nbuf; /* number of bcache bufs */
93 int bio_transient_maxcnt;
94 int ngroups_max; /* max # groups per process */
95 int nswbuf;
96 pid_t pid_max = PID_MAX;
97 u_long maxswzone; /* max swmeta KVA storage */
98 u_long maxbcache; /* max buffer cache KVA storage */
99 u_long maxpipekva; /* Limit on pipe KVA */
100 u_long maxphys; /* max raw I/O transfer size */
101 int vm_guest = VM_GUEST_NO; /* Running as virtual machine guest? */
102 u_long maxtsiz; /* max text size */
103 u_long dfldsiz; /* initial data size limit */
104 u_long maxdsiz; /* max data size */
105 u_long dflssiz; /* initial stack size limit */
106 u_long maxssiz; /* max stack size */
107 u_long sgrowsiz; /* amount to grow stack */
108
109 SYSCTL_INT(_kern, OID_AUTO, hz, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &hz, 0,
110 "Number of clock ticks per second");
111 SYSCTL_INT(_kern, OID_AUTO, hz_max, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, HZ_MAXIMUM,
112 "Maximum hz value supported");
113 SYSCTL_INT(_kern, OID_AUTO, hz_min, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, HZ_MINIMUM,
114 "Minimum hz value supported");
115 SYSCTL_INT(_kern, OID_AUTO, nbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nbuf, 0,
116 "Number of buffers in the buffer cache");
117 SYSCTL_INT(_kern, OID_AUTO, nswbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nswbuf, 0,
118 "Number of swap buffers");
119 SYSCTL_INT(_kern, OID_AUTO, msgbufsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &msgbufsize, 0,
120 "Size of the kernel message buffer");
121 SYSCTL_LONG(_kern, OID_AUTO, maxswzone, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxswzone, 0,
122 "Maximum memory for swap metadata");
123 SYSCTL_LONG(_kern, OID_AUTO, maxbcache, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxbcache, 0,
124 "Maximum value of vfs.maxbufspace");
125 SYSCTL_INT(_kern, OID_AUTO, bio_transient_maxcnt, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
126 &bio_transient_maxcnt, 0,
127 "Maximum number of transient BIOs mappings");
128 SYSCTL_ULONG(_kern, OID_AUTO, maxtsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxtsiz, 0,
129 "Maximum text size");
130 SYSCTL_ULONG(_kern, OID_AUTO, dfldsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dfldsiz, 0,
131 "Initial data size limit");
132 SYSCTL_ULONG(_kern, OID_AUTO, maxdsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxdsiz, 0,
133 "Maximum data size");
134 SYSCTL_ULONG(_kern, OID_AUTO, dflssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dflssiz, 0,
135 "Initial stack size limit");
136 SYSCTL_ULONG(_kern, OID_AUTO, maxssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxssiz, 0,
137 "Maximum stack size");
138 SYSCTL_ULONG(_kern, OID_AUTO, sgrowsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &sgrowsiz, 0,
139 "Amount to grow stack on a stack fault");
140 SYSCTL_PROC(_kern, OID_AUTO, vm_guest,
141 CTLFLAG_RD | CTLTYPE_STRING | CTLFLAG_MPSAFE, NULL, 0,
142 sysctl_kern_vm_guest, "A",
143 "Virtual machine guest detected?");
144
145 /*
146 * The elements of this array are ordered based upon the values of the
147 * corresponding enum VM_GUEST members.
148 */
149 static const char *const vm_guest_sysctl_names[] = {
150 [VM_GUEST_NO] = "none",
151 [VM_GUEST_VM] = "generic",
152 [VM_GUEST_XEN] = "xen",
153 [VM_GUEST_HV] = "hv",
154 [VM_GUEST_VMWARE] = "vmware",
155 [VM_GUEST_KVM] = "kvm",
156 [VM_GUEST_BHYVE] = "bhyve",
157 [VM_GUEST_VBOX] = "vbox",
158 [VM_GUEST_PARALLELS] = "parallels",
159 };
160 _Static_assert(nitems(vm_guest_sysctl_names) == VM_GUEST_LAST,
161 "new vm guest type not added to vm_guest_sysctl_names");
162
163 /*
164 * Boot time overrides that are not scaled against main memory
165 */
166 void
init_param1(void)167 init_param1(void)
168 {
169
170 TSENTER();
171
172 /*
173 * arm64 and riscv currently hard-code the thread0 kstack size
174 * to KSTACK_PAGES, ignoring the tunable.
175 */
176 TUNABLE_INT_FETCH("kern.kstack_pages", &kstack_pages);
177
178 hz = -1;
179 TUNABLE_INT_FETCH("kern.hz", &hz);
180 if (hz == -1)
181 hz = vm_guest > VM_GUEST_NO ? HZ_VM : HZ;
182
183 /* range check the "hz" value */
184 if (__predict_false(hz < HZ_MINIMUM))
185 hz = HZ_MINIMUM;
186 else if (__predict_false(hz > HZ_MAXIMUM))
187 hz = HZ_MAXIMUM;
188
189 tick = 1000000 / hz;
190 tick_sbt = SBT_1S / hz;
191 tick_bt = sbttobt(tick_sbt);
192 tick_seconds_max = INT_MAX / hz;
193
194 /*
195 * Arrange for ticks to wrap 10 minutes after boot to help catch
196 * sign problems sooner.
197 */
198 ticks = INT_MAX - (hz * 10 * 60);
199
200 vn_lock_pair_pause_max = hz / 100;
201 if (vn_lock_pair_pause_max == 0)
202 vn_lock_pair_pause_max = 1;
203
204 #ifdef VM_SWZONE_SIZE_MAX
205 maxswzone = VM_SWZONE_SIZE_MAX;
206 #endif
207 TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone);
208 #ifdef VM_BCACHE_SIZE_MAX
209 maxbcache = VM_BCACHE_SIZE_MAX;
210 #endif
211 TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache);
212 msgbufsize = MSGBUF_SIZE;
213 TUNABLE_INT_FETCH("kern.msgbufsize", &msgbufsize);
214
215 maxtsiz = MAXTSIZ;
216 TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz);
217 dfldsiz = DFLDSIZ;
218 TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz);
219 maxdsiz = MAXDSIZ;
220 TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz);
221 dflssiz = DFLSSIZ;
222 TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz);
223 maxssiz = MAXSSIZ;
224 TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz);
225 sgrowsiz = SGROWSIZ;
226 TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz);
227
228 /*
229 * Let the administrator set {NGROUPS_MAX}, but disallow values
230 * less than NGROUPS_MAX which would violate POSIX.1-2008 or
231 * greater than INT_MAX-1 which would result in overflow.
232 */
233 ngroups_max = NGROUPS_MAX;
234 TUNABLE_INT_FETCH("kern.ngroups", &ngroups_max);
235 if (ngroups_max < NGROUPS_MAX)
236 ngroups_max = NGROUPS_MAX;
237
238 /*
239 * Only allow to lower the maximal pid.
240 * Prevent setting up a non-bootable system if pid_max is too low.
241 */
242 TUNABLE_INT_FETCH("kern.pid_max", &pid_max);
243 if (pid_max > PID_MAX)
244 pid_max = PID_MAX;
245 else if (pid_max < 300)
246 pid_max = 300;
247
248 TUNABLE_INT_FETCH("vfs.unmapped_buf_allowed", &unmapped_buf_allowed);
249 TSEXIT();
250 }
251
252 /*
253 * Boot time overrides that are scaled against main memory
254 */
255 void
init_param2(long physpages)256 init_param2(long physpages)
257 {
258
259 TSENTER();
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 #ifdef VM_MAX_AUTOTUNE_MAXUSERS
268 if (maxusers > VM_MAX_AUTOTUNE_MAXUSERS)
269 maxusers = VM_MAX_AUTOTUNE_MAXUSERS;
270 #endif
271 /*
272 * Scales down the function in which maxusers grows once
273 * we hit 384.
274 */
275 if (maxusers > 384)
276 maxusers = 384 + ((maxusers - 384) / 8);
277 }
278
279 /*
280 * The following can be overridden after boot via sysctl. Note:
281 * unless overridden, these macros are ultimately based on maxusers.
282 * Limit maxproc so that kmap entries cannot be exhausted by
283 * processes.
284 */
285 maxproc = NPROC;
286 TUNABLE_INT_FETCH("kern.maxproc", &maxproc);
287 if (maxproc > (physpages / 12))
288 maxproc = physpages / 12;
289 if (maxproc > pid_max)
290 maxproc = pid_max;
291 maxprocperuid = (maxproc * 9) / 10;
292
293 /*
294 * The default limit for maxfiles is 1/12 of the number of
295 * physical page but not less than 16 times maxusers.
296 * At most it can be 1/6 the number of physical pages.
297 */
298 maxfiles = imax(MAXFILES, physpages / 8);
299 TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles);
300 if (maxfiles > (physpages / 4))
301 maxfiles = physpages / 4;
302 maxfilesperproc = (maxfiles / 10) * 9;
303 TUNABLE_INT_FETCH("kern.maxfilesperproc", &maxfilesperproc);
304
305 /*
306 * Cannot be changed after boot.
307 */
308 nbuf = NBUF;
309 TUNABLE_INT_FETCH("kern.nbuf", &nbuf);
310 TUNABLE_INT_FETCH("kern.bio_transient_maxcnt", &bio_transient_maxcnt);
311 maxphys = MAXPHYS;
312 TUNABLE_ULONG_FETCH("kern.maxphys", &maxphys);
313 if (maxphys == 0) {
314 maxphys = MAXPHYS;
315 } else if (__bitcountl(maxphys) != 1) { /* power of two */
316 if (flsl(maxphys) == NBBY * sizeof(maxphys))
317 maxphys = MAXPHYS;
318 else
319 maxphys = 1UL << flsl(maxphys);
320 }
321 if (maxphys < PAGE_SIZE)
322 maxphys = MAXPHYS;
323
324 /*
325 * Physical buffers are pre-allocated buffers (struct buf) that
326 * are used as temporary holders for I/O, such as paging I/O.
327 */
328 TUNABLE_INT_FETCH("kern.nswbuf", &nswbuf);
329
330 /*
331 * The default for maxpipekva is min(1/64 of the kernel address space,
332 * max(1/64 of main memory, 512KB)). See sys_pipe.c for more details.
333 */
334 maxpipekva = ptoa(physpages / 64);
335 TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva);
336 if (maxpipekva < 512 * 1024)
337 maxpipekva = 512 * 1024;
338 if (maxpipekva > (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 64)
339 maxpipekva = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) /
340 64;
341 TSEXIT();
342 }
343
344 /*
345 * Sysctl stringifying handler for kern.vm_guest.
346 */
347 static int
sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS)348 sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS)
349 {
350 return (SYSCTL_OUT_STR(req, vm_guest_sysctl_names[vm_guest]));
351 }
352