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/_maxphys.h>
45 #include <sys/systm.h>
46 #include <sys/buf.h>
47 #include <sys/kernel.h>
48 #include <sys/limits.h>
49 #include <sys/msgbuf.h>
50 #include <sys/sysctl.h>
51 #include <sys/proc.h>
52 #include <sys/vnode.h>
53
54 #include <vm/vm.h>
55 #include <vm/vm_param.h>
56 #include <vm/pmap.h>
57
58 /*
59 * System parameter formulae.
60 */
61
62 #ifndef HZ
63 # define HZ 1000
64 # ifndef HZ_VM
65 # define HZ_VM 100
66 # endif
67 #else
68 # ifndef HZ_VM
69 # define HZ_VM HZ
70 # endif
71 #endif
72 #define NPROC (20 + 16 * maxusers)
73 #ifndef NBUF
74 #define NBUF 0
75 #endif
76 #ifndef MAXFILES
77 #define MAXFILES (40 + 32 * maxusers)
78 #endif
79
80 static int sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS);
81
82 int hz; /* system clock's frequency */
83 int tick; /* usec per tick (1000000 / hz) */
84 time_t tick_seconds_max; /* max hz * seconds an integer can hold */
85 struct bintime tick_bt; /* bintime per tick (1s / hz) */
86 sbintime_t tick_sbt;
87 int maxusers; /* base tunable */
88 int maxproc; /* maximum # of processes */
89 int maxprocperuid; /* max # of procs per user */
90 int maxfiles; /* sys. wide open files limit */
91 int maxfilesperproc; /* per-proc open files limit */
92 int msgbufsize; /* size of kernel message buffer */
93 int nbuf; /* number of bcache bufs */
94 int bio_transient_maxcnt;
95 int ngroups_max; /* max # groups per process */
96 int nswbuf;
97 pid_t pid_max = PID_MAX;
98 u_long maxswzone; /* max swmeta KVA storage */
99 u_long maxbcache; /* max buffer cache KVA storage */
100 u_long maxpipekva; /* Limit on pipe KVA */
101 u_long maxphys; /* max raw I/O transfer size */
102 int vm_guest = VM_GUEST_NO; /* Running as virtual machine guest? */
103 u_long maxtsiz; /* max text size */
104 u_long dfldsiz; /* initial data size limit */
105 u_long maxdsiz; /* max data size */
106 u_long dflssiz; /* initial stack size limit */
107 u_long maxssiz; /* max stack size */
108 u_long sgrowsiz; /* amount to grow stack */
109
110 SYSCTL_INT(_kern, OID_AUTO, hz, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &hz, 0,
111 "Number of clock ticks per second");
112 SYSCTL_INT(_kern, OID_AUTO, hz_max, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, HZ_MAXIMUM,
113 "Maximum hz value supported");
114 SYSCTL_INT(_kern, OID_AUTO, hz_min, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, HZ_MINIMUM,
115 "Minimum hz value supported");
116 SYSCTL_INT(_kern, OID_AUTO, nbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nbuf, 0,
117 "Number of buffers in the buffer cache");
118 SYSCTL_INT(_kern, OID_AUTO, nswbuf, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &nswbuf, 0,
119 "Number of swap buffers");
120 SYSCTL_INT(_kern, OID_AUTO, msgbufsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &msgbufsize, 0,
121 "Size of the kernel message buffer");
122 SYSCTL_LONG(_kern, OID_AUTO, maxswzone, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxswzone, 0,
123 "Maximum memory for swap metadata");
124 SYSCTL_LONG(_kern, OID_AUTO, maxbcache, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxbcache, 0,
125 "Maximum value of vfs.maxbufspace");
126 SYSCTL_INT(_kern, OID_AUTO, bio_transient_maxcnt, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
127 &bio_transient_maxcnt, 0,
128 "Maximum number of transient BIOs mappings");
129 SYSCTL_ULONG(_kern, OID_AUTO, maxtsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxtsiz, 0,
130 "Maximum text size");
131 SYSCTL_ULONG(_kern, OID_AUTO, dfldsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dfldsiz, 0,
132 "Initial data size limit");
133 SYSCTL_ULONG(_kern, OID_AUTO, maxdsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxdsiz, 0,
134 "Maximum data size");
135 SYSCTL_ULONG(_kern, OID_AUTO, dflssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &dflssiz, 0,
136 "Initial stack size limit");
137 SYSCTL_ULONG(_kern, OID_AUTO, maxssiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &maxssiz, 0,
138 "Maximum stack size");
139 SYSCTL_ULONG(_kern, OID_AUTO, sgrowsiz, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, &sgrowsiz, 0,
140 "Amount to grow stack on a stack fault");
141 SYSCTL_PROC(_kern, OID_AUTO, vm_guest,
142 CTLFLAG_RD | CTLTYPE_STRING | CTLFLAG_MPSAFE, NULL, 0,
143 sysctl_kern_vm_guest, "A",
144 "Virtual machine guest detected?");
145
146 /*
147 * The elements of this array are ordered based upon the values of the
148 * corresponding enum VM_GUEST members.
149 */
150 static const char *const vm_guest_sysctl_names[] = {
151 [VM_GUEST_NO] = "none",
152 [VM_GUEST_VM] = "generic",
153 [VM_GUEST_XEN] = "xen",
154 [VM_GUEST_HV] = "hv",
155 [VM_GUEST_VMWARE] = "vmware",
156 [VM_GUEST_KVM] = "kvm",
157 [VM_GUEST_BHYVE] = "bhyve",
158 [VM_GUEST_VBOX] = "vbox",
159 [VM_GUEST_PARALLELS] = "parallels",
160 };
161 _Static_assert(nitems(vm_guest_sysctl_names) == VM_GUEST_LAST,
162 "new vm guest type not added to vm_guest_sysctl_names");
163
164 /*
165 * Boot time overrides that are not scaled against main memory
166 */
167 void
init_param1(void)168 init_param1(void)
169 {
170
171 TSENTER();
172
173 /*
174 * arm64 and riscv currently hard-code the thread0 kstack size
175 * to KSTACK_PAGES, ignoring the tunable.
176 */
177 TUNABLE_INT_FETCH("kern.kstack_pages", &kstack_pages);
178
179 hz = -1;
180 TUNABLE_INT_FETCH("kern.hz", &hz);
181 if (hz == -1)
182 hz = vm_guest > VM_GUEST_NO ? HZ_VM : HZ;
183
184 /* range check the "hz" value */
185 if (__predict_false(hz < HZ_MINIMUM))
186 hz = HZ_MINIMUM;
187 else if (__predict_false(hz > HZ_MAXIMUM))
188 hz = HZ_MAXIMUM;
189
190 tick = 1000000 / hz;
191 tick_sbt = SBT_1S / hz;
192 tick_bt = sbttobt(tick_sbt);
193 tick_seconds_max = INT_MAX / hz;
194
195 /*
196 * Arrange for ticks to wrap 10 minutes after boot to help catch
197 * sign problems sooner.
198 */
199 ticks = INT_MAX - (hz * 10 * 60);
200
201 vn_lock_pair_pause_max = hz / 100;
202 if (vn_lock_pair_pause_max == 0)
203 vn_lock_pair_pause_max = 1;
204
205 #ifdef VM_SWZONE_SIZE_MAX
206 maxswzone = VM_SWZONE_SIZE_MAX;
207 #endif
208 TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone);
209 #ifdef VM_BCACHE_SIZE_MAX
210 maxbcache = VM_BCACHE_SIZE_MAX;
211 #endif
212 TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache);
213 msgbufsize = MSGBUF_SIZE;
214 TUNABLE_INT_FETCH("kern.msgbufsize", &msgbufsize);
215
216 maxtsiz = MAXTSIZ;
217 TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz);
218 dfldsiz = DFLDSIZ;
219 TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz);
220 maxdsiz = MAXDSIZ;
221 TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz);
222 dflssiz = DFLSSIZ;
223 TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz);
224 maxssiz = MAXSSIZ;
225 TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz);
226 sgrowsiz = SGROWSIZ;
227 TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz);
228
229 /*
230 * Let the administrator set {NGROUPS_MAX}, but disallow values
231 * less than NGROUPS_MAX which would violate POSIX.1-2008 or
232 * greater than INT_MAX-1 which would result in overflow.
233 */
234 ngroups_max = NGROUPS_MAX;
235 TUNABLE_INT_FETCH("kern.ngroups", &ngroups_max);
236 if (ngroups_max < NGROUPS_MAX)
237 ngroups_max = NGROUPS_MAX;
238
239 /*
240 * Only allow to lower the maximal pid.
241 * Prevent setting up a non-bootable system if pid_max is too low.
242 */
243 TUNABLE_INT_FETCH("kern.pid_max", &pid_max);
244 if (pid_max > PID_MAX)
245 pid_max = PID_MAX;
246 else if (pid_max < 300)
247 pid_max = 300;
248
249 TUNABLE_INT_FETCH("vfs.unmapped_buf_allowed", &unmapped_buf_allowed);
250 TSEXIT();
251 }
252
253 /*
254 * Boot time overrides that are scaled against main memory
255 */
256 void
init_param2(long physpages)257 init_param2(long physpages)
258 {
259
260 TSENTER();
261 /* Base parameters */
262 maxusers = MAXUSERS;
263 TUNABLE_INT_FETCH("kern.maxusers", &maxusers);
264 if (maxusers == 0) {
265 maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE);
266 if (maxusers < 32)
267 maxusers = 32;
268 #ifdef VM_MAX_AUTOTUNE_MAXUSERS
269 if (maxusers > VM_MAX_AUTOTUNE_MAXUSERS)
270 maxusers = VM_MAX_AUTOTUNE_MAXUSERS;
271 #endif
272 /*
273 * Scales down the function in which maxusers grows once
274 * we hit 384.
275 */
276 if (maxusers > 384)
277 maxusers = 384 + ((maxusers - 384) / 8);
278 }
279
280 /*
281 * The following can be overridden after boot via sysctl. Note:
282 * unless overridden, these macros are ultimately based on maxusers.
283 * Limit maxproc so that kmap entries cannot be exhausted by
284 * processes.
285 */
286 maxproc = NPROC;
287 TUNABLE_INT_FETCH("kern.maxproc", &maxproc);
288 if (maxproc > (physpages / 12))
289 maxproc = physpages / 12;
290 if (maxproc > pid_max)
291 maxproc = pid_max;
292 maxprocperuid = (maxproc * 9) / 10;
293
294 /*
295 * The default limit for maxfiles is 1/12 of the number of
296 * physical page but not less than 16 times maxusers.
297 * At most it can be 1/6 the number of physical pages.
298 */
299 maxfiles = imax(MAXFILES, physpages / 8);
300 TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles);
301 if (maxfiles > (physpages / 4))
302 maxfiles = physpages / 4;
303 maxfilesperproc = (maxfiles / 10) * 9;
304 TUNABLE_INT_FETCH("kern.maxfilesperproc", &maxfilesperproc);
305
306 /*
307 * Cannot be changed after boot.
308 */
309 nbuf = NBUF;
310 TUNABLE_INT_FETCH("kern.nbuf", &nbuf);
311 TUNABLE_INT_FETCH("kern.bio_transient_maxcnt", &bio_transient_maxcnt);
312 maxphys = MAXPHYS;
313 TUNABLE_ULONG_FETCH("kern.maxphys", &maxphys);
314 if (maxphys == 0) {
315 maxphys = MAXPHYS;
316 } else if (__bitcountl(maxphys) != 1) { /* power of two */
317 if (flsl(maxphys) == NBBY * sizeof(maxphys))
318 maxphys = MAXPHYS;
319 else
320 maxphys = 1UL << flsl(maxphys);
321 }
322 if (maxphys < PAGE_SIZE)
323 maxphys = MAXPHYS;
324
325 /*
326 * Physical buffers are pre-allocated buffers (struct buf) that
327 * are used as temporary holders for I/O, such as paging I/O.
328 */
329 TUNABLE_INT_FETCH("kern.nswbuf", &nswbuf);
330
331 /*
332 * The default for maxpipekva is min(1/64 of the kernel address space,
333 * max(1/64 of main memory, 512KB)). See sys_pipe.c for more details.
334 */
335 maxpipekva = ptoa(physpages / 64);
336 TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva);
337 if (maxpipekva < 512 * 1024)
338 maxpipekva = 512 * 1024;
339 if (maxpipekva > (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 64)
340 maxpipekva = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) /
341 64;
342 TSEXIT();
343 }
344
345 /*
346 * Sysctl stringifying handler for kern.vm_guest.
347 */
348 static int
sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS)349 sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS)
350 {
351 return (SYSCTL_OUT_STR(req, vm_guest_sysctl_names[vm_guest]));
352 }
353