xref: /freebsd/sys/vm/vm_domainset.c (revision f81cdf24ba5436367377f7c8e8f51f6df2a75ca7)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2017,	Jeffrey Roberson <jeff@freebsd.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice unmodified, this list of conditions, and the following
12  *    disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  *
28  */
29 
30 #include <sys/cdefs.h>
31 #include "opt_vm.h"
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/bitset.h>
36 #include <sys/domainset.h>
37 #include <sys/proc.h>
38 #include <sys/lock.h>
39 #include <sys/mutex.h>
40 #include <sys/malloc.h>
41 #include <sys/rwlock.h>
42 #include <sys/vmmeter.h>
43 
44 #include <vm/vm.h>
45 #include <vm/vm_param.h>
46 #include <vm/vm_domainset.h>
47 #include <vm/vm_object.h>
48 #include <vm/vm_page.h>
49 #include <vm/vm_phys.h>
50 
51 #ifdef NUMA
52 /*
53  * Iterators are written such that the first nowait pass has as short a
54  * codepath as possible to eliminate bloat from the allocator.  It is
55  * assumed that most allocations are successful.
56  */
57 
58 static int vm_domainset_default_stride = 64;
59 
60 /*
61  * Determine which policy is to be used for this allocation.
62  */
63 static void
64 vm_domainset_iter_init(struct vm_domainset_iter *di, struct domainset *ds,
65     int *iter, struct vm_object *obj, vm_pindex_t pindex)
66 {
67 
68 	di->di_domain = ds;
69 	di->di_iter = iter;
70 	di->di_policy = ds->ds_policy;
71 	DOMAINSET_COPY(&ds->ds_mask, &di->di_valid_mask);
72 	if (di->di_policy == DOMAINSET_POLICY_INTERLEAVE) {
73 #if VM_NRESERVLEVEL > 0
74 		if (vm_object_reserv(obj)) {
75 			/*
76 			 * Color the pindex so we end up on the correct
77 			 * reservation boundary.
78 			 */
79 			pindex += obj->pg_color;
80 			pindex >>= VM_LEVEL_0_ORDER;
81 		} else
82 #endif
83 			pindex /= vm_domainset_default_stride;
84 		/*
85 		 * Offset pindex so the first page of each object does
86 		 * not end up in domain 0.
87 		 */
88 		if (obj != NULL)
89 			pindex += (((uintptr_t)obj) / sizeof(*obj));
90 		di->di_offset = pindex;
91 	}
92 	/* Skip domains below min on the first pass. */
93 	di->di_minskip = true;
94 }
95 
96 static void
97 vm_domainset_iter_rr(struct vm_domainset_iter *di, int *domain)
98 {
99 
100 	*domain = di->di_domain->ds_order[
101 	    ++(*di->di_iter) % di->di_domain->ds_cnt];
102 }
103 
104 static void
105 vm_domainset_iter_prefer(struct vm_domainset_iter *di, int *domain)
106 {
107 	int d;
108 
109 	do {
110 		d = di->di_domain->ds_order[
111 		    ++(*di->di_iter) % di->di_domain->ds_cnt];
112 	} while (d == di->di_domain->ds_prefer);
113 	*domain = d;
114 }
115 
116 static void
117 vm_domainset_iter_interleave(struct vm_domainset_iter *di, int *domain)
118 {
119 	int d;
120 
121 	d = di->di_offset % di->di_domain->ds_cnt;
122 	*di->di_iter = d;
123 	*domain = di->di_domain->ds_order[d];
124 }
125 
126 static void
127 vm_domainset_iter_next(struct vm_domainset_iter *di, int *domain)
128 {
129 
130 	KASSERT(di->di_n > 0,
131 	    ("vm_domainset_iter_first: Invalid n %d", di->di_n));
132 	switch (di->di_policy) {
133 	case DOMAINSET_POLICY_FIRSTTOUCH:
134 		/*
135 		 * To prevent impossible allocations we convert an invalid
136 		 * first-touch to round-robin.
137 		 */
138 		/* FALLTHROUGH */
139 	case DOMAINSET_POLICY_INTERLEAVE:
140 		/* FALLTHROUGH */
141 	case DOMAINSET_POLICY_ROUNDROBIN:
142 		vm_domainset_iter_rr(di, domain);
143 		break;
144 	case DOMAINSET_POLICY_PREFER:
145 		vm_domainset_iter_prefer(di, domain);
146 		break;
147 	default:
148 		panic("vm_domainset_iter_first: Unknown policy %d",
149 		    di->di_policy);
150 	}
151 	KASSERT(*domain < vm_ndomains,
152 	    ("vm_domainset_iter_next: Invalid domain %d", *domain));
153 }
154 
155 static void
156 vm_domainset_iter_first(struct vm_domainset_iter *di, int *domain)
157 {
158 
159 	switch (di->di_policy) {
160 	case DOMAINSET_POLICY_FIRSTTOUCH:
161 		*domain = PCPU_GET(domain);
162 		if (DOMAINSET_ISSET(*domain, &di->di_valid_mask)) {
163 			/*
164 			 * Add an extra iteration because we will visit the
165 			 * current domain a second time in the rr iterator.
166 			 */
167 			di->di_n = di->di_domain->ds_cnt + 1;
168 			break;
169 		}
170 		/*
171 		 * To prevent impossible allocations we convert an invalid
172 		 * first-touch to round-robin.
173 		 */
174 		/* FALLTHROUGH */
175 	case DOMAINSET_POLICY_ROUNDROBIN:
176 		di->di_n = di->di_domain->ds_cnt;
177 		vm_domainset_iter_rr(di, domain);
178 		break;
179 	case DOMAINSET_POLICY_PREFER:
180 		*domain = di->di_domain->ds_prefer;
181 		di->di_n = di->di_domain->ds_cnt;
182 		break;
183 	case DOMAINSET_POLICY_INTERLEAVE:
184 		vm_domainset_iter_interleave(di, domain);
185 		di->di_n = di->di_domain->ds_cnt;
186 		break;
187 	default:
188 		panic("vm_domainset_iter_first: Unknown policy %d",
189 		    di->di_policy);
190 	}
191 	KASSERT(di->di_n > 0,
192 	    ("vm_domainset_iter_first: Invalid n %d", di->di_n));
193 	KASSERT(*domain < vm_ndomains,
194 	    ("vm_domainset_iter_first: Invalid domain %d", *domain));
195 }
196 
197 void
198 vm_domainset_iter_page_init(struct vm_domainset_iter *di, struct vm_object *obj,
199     vm_pindex_t pindex, int *domain, int *req)
200 {
201 	struct domainset_ref *dr;
202 
203 	/*
204 	 * Object policy takes precedence over thread policy.  The policies
205 	 * are immutable and unsynchronized.  Updates can race but pointer
206 	 * loads are assumed to be atomic.
207 	 */
208 	if (obj != NULL && obj->domain.dr_policy != NULL)
209 		dr = &obj->domain;
210 	else
211 		dr = &curthread->td_domain;
212 	vm_domainset_iter_init(di, dr->dr_policy, &dr->dr_iter, obj, pindex);
213 	di->di_flags = *req;
214 	*req = (di->di_flags & ~(VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL)) |
215 	    VM_ALLOC_NOWAIT;
216 	vm_domainset_iter_first(di, domain);
217 	if (vm_page_count_min_domain(*domain))
218 		vm_domainset_iter_page(di, obj, domain);
219 }
220 
221 int
222 vm_domainset_iter_page(struct vm_domainset_iter *di, struct vm_object *obj,
223     int *domain)
224 {
225 	if (__predict_false(DOMAINSET_EMPTY(&di->di_valid_mask)))
226 		return (ENOMEM);
227 
228 	/* If there are more domains to visit we run the iterator. */
229 	while (--di->di_n != 0) {
230 		vm_domainset_iter_next(di, domain);
231 		if (DOMAINSET_ISSET(*domain, &di->di_valid_mask) &&
232 		    (!di->di_minskip || !vm_page_count_min_domain(*domain)))
233 			return (0);
234 	}
235 
236 	/* If we skipped domains below min restart the search. */
237 	if (di->di_minskip) {
238 		di->di_minskip = false;
239 		vm_domainset_iter_first(di, domain);
240 		return (0);
241 	}
242 
243 	/* If we visited all domains and this was a NOWAIT we return error. */
244 	if ((di->di_flags & (VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL)) == 0)
245 		return (ENOMEM);
246 
247 	/* Wait for one of the domains to accumulate some free pages. */
248 	if (obj != NULL)
249 		VM_OBJECT_WUNLOCK(obj);
250 	vm_wait_doms(&di->di_valid_mask, 0);
251 	if (obj != NULL)
252 		VM_OBJECT_WLOCK(obj);
253 	if ((di->di_flags & VM_ALLOC_WAITFAIL) != 0)
254 		return (ENOMEM);
255 
256 	/* Restart the search. */
257 	vm_domainset_iter_first(di, domain);
258 
259 	return (0);
260 }
261 
262 static void
263 _vm_domainset_iter_policy_init(struct vm_domainset_iter *di, int *domain,
264     int *flags)
265 {
266 
267 	di->di_flags = *flags;
268 	*flags = (di->di_flags & ~M_WAITOK) | M_NOWAIT;
269 	vm_domainset_iter_first(di, domain);
270 	if (vm_page_count_min_domain(*domain))
271 		vm_domainset_iter_policy(di, domain);
272 }
273 
274 void
275 vm_domainset_iter_policy_init(struct vm_domainset_iter *di,
276     struct domainset *ds, int *domain, int *flags)
277 {
278 
279 	vm_domainset_iter_init(di, ds, &curthread->td_domain.dr_iter, NULL, 0);
280 	_vm_domainset_iter_policy_init(di, domain, flags);
281 }
282 
283 void
284 vm_domainset_iter_policy_ref_init(struct vm_domainset_iter *di,
285     struct domainset_ref *dr, int *domain, int *flags)
286 {
287 
288 	vm_domainset_iter_init(di, dr->dr_policy, &dr->dr_iter, NULL, 0);
289 	_vm_domainset_iter_policy_init(di, domain, flags);
290 }
291 
292 int
293 vm_domainset_iter_policy(struct vm_domainset_iter *di, int *domain)
294 {
295 	if (DOMAINSET_EMPTY(&di->di_valid_mask))
296 		return (ENOMEM);
297 
298 	/* If there are more domains to visit we run the iterator. */
299 	while (--di->di_n != 0) {
300 		vm_domainset_iter_next(di, domain);
301 		if (DOMAINSET_ISSET(*domain, &di->di_valid_mask) &&
302 		    (!di->di_minskip || !vm_page_count_min_domain(*domain)))
303 			return (0);
304 	}
305 
306 	/* If we skipped domains below min restart the search. */
307 	if (di->di_minskip) {
308 		di->di_minskip = false;
309 		vm_domainset_iter_first(di, domain);
310 		return (0);
311 	}
312 
313 	/* If we visited all domains and this was a NOWAIT we return error. */
314 	if ((di->di_flags & M_WAITOK) == 0)
315 		return (ENOMEM);
316 
317 	/* Wait for one of the domains to accumulate some free pages. */
318 	vm_wait_doms(&di->di_valid_mask, 0);
319 
320 	/* Restart the search. */
321 	vm_domainset_iter_first(di, domain);
322 
323 	return (0);
324 }
325 
326 void
327 vm_domainset_iter_ignore(struct vm_domainset_iter *di, int domain)
328 {
329 	KASSERT(DOMAINSET_ISSET(domain, &di->di_valid_mask),
330 	    ("%s: domain %d not present in di_valid_mask for di %p",
331 	    __func__, domain, di));
332 	DOMAINSET_CLR(domain, &di->di_valid_mask);
333 }
334 
335 #else /* !NUMA */
336 
337 int
338 vm_domainset_iter_page(struct vm_domainset_iter *di, struct vm_object *obj,
339     int *domain)
340 {
341 
342 	return (EJUSTRETURN);
343 }
344 
345 void
346 vm_domainset_iter_page_init(struct vm_domainset_iter *di, struct vm_object *obj,
347     vm_pindex_t pindex, int *domain, int *flags)
348 {
349 
350 	*domain = 0;
351 }
352 
353 int
354 vm_domainset_iter_policy(struct vm_domainset_iter *di, int *domain)
355 {
356 
357 	return (EJUSTRETURN);
358 }
359 
360 void
361 vm_domainset_iter_policy_init(struct vm_domainset_iter *di,
362     struct domainset *ds, int *domain, int *flags)
363 {
364 
365 	*domain = 0;
366 }
367 
368 void
369 vm_domainset_iter_policy_ref_init(struct vm_domainset_iter *di,
370     struct domainset_ref *dr, int *domain, int *flags)
371 {
372 
373 	*domain = 0;
374 }
375 
376 void
377 vm_domainset_iter_ignore(struct vm_domainset_iter *di __unused,
378     int domain __unused)
379 {
380 }
381 
382 #endif /* NUMA */
383