2 * Copyright (c) 2015 Adrian Chadd <adrian@FreeBSD.org>.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer,
10 * without modification.
11 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
12 * similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
13 * redistribution must be conditioned upon including a substantially
14 * similar Disclaimer requirement for further binary redistribution.
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
20 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
21 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
22 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
25 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
27 * THE POSSIBILITY OF SUCH DAMAGES.
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
36 #include <sys/param.h>
37 #include <sys/systm.h>
39 #include <sys/kernel.h>
40 #include <sys/malloc.h>
41 #include <sys/mutex.h>
45 #include <sys/queue.h>
46 #include <sys/rwlock.h>
48 #include <sys/sysctl.h>
50 #include <sys/vmmeter.h>
56 #include <vm/vm_param.h>
57 #include <vm/vm_kern.h>
58 #include <vm/vm_object.h>
59 #include <vm/vm_page.h>
60 #include <vm/vm_phys.h>
62 #include <vm/vm_domain.h>
65 vm_domain_rr_selectdomain(void)
73 td->td_dom_rr_idx %= vm_ndomains;
74 return (td->td_dom_rr_idx);
81 * This implements a very simple set of VM domain memory allocation
82 * policies and iterators.
86 * A VM domain policy represents a desired VM domain policy.
87 * Iterators implement searching through VM domains in a specific
92 * When setting a policy, the caller must establish their own
93 * exclusive write protection for the contents of the domain
97 vm_domain_policy_init(struct vm_domain_policy *vp)
100 bzero(vp, sizeof(*vp));
101 vp->p.policy = VM_POLICY_NONE;
107 vm_domain_policy_set(struct vm_domain_policy *vp,
108 vm_domain_policy_type_t vt, int domain)
111 seq_write_begin(&vp->seq);
113 vp->p.domain = domain;
114 seq_write_end(&vp->seq);
119 * Take a local copy of a policy.
121 * The destination policy isn't write-barriered; this is used
122 * for doing local copies into something that isn't shared.
125 vm_domain_policy_localcopy(struct vm_domain_policy *dst,
126 const struct vm_domain_policy *src)
131 seq = seq_read(&src->seq);
133 if (seq_consistent(&src->seq, seq))
140 * Take a write-barrier copy of a policy.
142 * The destination policy is write -barriered; this is used
143 * for doing copies into policies that may be read by other
147 vm_domain_policy_copy(struct vm_domain_policy *dst,
148 const struct vm_domain_policy *src)
151 struct vm_domain_policy d;
154 seq = seq_read(&src->seq);
156 if (seq_consistent(&src->seq, seq)) {
157 seq_write_begin(&dst->seq);
158 dst->p.domain = d.p.domain;
159 dst->p.policy = d.p.policy;
160 seq_write_end(&dst->seq);
168 vm_domain_policy_validate(const struct vm_domain_policy *vp)
171 switch (vp->p.policy) {
173 case VM_POLICY_ROUND_ROBIN:
174 case VM_POLICY_FIRST_TOUCH:
175 case VM_POLICY_FIRST_TOUCH_ROUND_ROBIN:
176 if (vp->p.domain == -1)
179 case VM_POLICY_FIXED_DOMAIN:
180 case VM_POLICY_FIXED_DOMAIN_ROUND_ROBIN:
181 if (vp->p.domain >= 0 && vp->p.domain < vm_ndomains)
191 vm_domain_policy_cleanup(struct vm_domain_policy *vp)
199 vm_domain_iterator_init(struct vm_domain_iterator *vi)
202 /* Nothing to do for now */
207 * Manually setup an iterator with the given details.
210 vm_domain_iterator_set(struct vm_domain_iterator *vi,
211 vm_domain_policy_type_t vt, int domain)
215 case VM_POLICY_FIXED_DOMAIN:
216 vi->policy = VM_POLICY_FIXED_DOMAIN;
220 case VM_POLICY_FIXED_DOMAIN_ROUND_ROBIN:
221 vi->policy = VM_POLICY_FIXED_DOMAIN_ROUND_ROBIN;
225 case VM_POLICY_FIRST_TOUCH:
226 vi->policy = VM_POLICY_FIRST_TOUCH;
227 vi->domain = PCPU_GET(domain);
230 case VM_POLICY_FIRST_TOUCH_ROUND_ROBIN:
231 vi->policy = VM_POLICY_FIRST_TOUCH_ROUND_ROBIN;
232 vi->domain = PCPU_GET(domain);
235 case VM_POLICY_ROUND_ROBIN:
237 vi->policy = VM_POLICY_ROUND_ROBIN;
246 * Setup an iterator based on the given policy.
249 _vm_domain_iterator_set_policy(struct vm_domain_iterator *vi,
250 const struct vm_domain_policy *vt)
253 * Initialise the iterator.
255 * For first-touch, the initial domain is set
256 * via the current thread CPU domain.
258 * For fixed-domain, it's assumed that the
259 * caller has initialised the specific domain
262 switch (vt->p.policy) {
263 case VM_POLICY_FIXED_DOMAIN:
264 vi->policy = vt->p.policy;
265 vi->domain = vt->p.domain;
268 case VM_POLICY_FIXED_DOMAIN_ROUND_ROBIN:
269 vi->policy = vt->p.policy;
270 vi->domain = vt->p.domain;
273 case VM_POLICY_FIRST_TOUCH:
274 vi->policy = vt->p.policy;
275 vi->domain = PCPU_GET(domain);
278 case VM_POLICY_FIRST_TOUCH_ROUND_ROBIN:
279 vi->policy = vt->p.policy;
280 vi->domain = PCPU_GET(domain);
283 case VM_POLICY_ROUND_ROBIN:
286 * Default to round-robin policy.
288 vi->policy = VM_POLICY_ROUND_ROBIN;
296 vm_domain_iterator_set_policy(struct vm_domain_iterator *vi,
297 const struct vm_domain_policy *vt)
300 struct vm_domain_policy vt_lcl;
303 seq = seq_read(&vt->seq);
305 if (seq_consistent(&vt->seq, seq)) {
306 _vm_domain_iterator_set_policy(vi, &vt_lcl);
314 * Return the next VM domain to use.
316 * Returns 0 w/ domain set to the next domain to use, or
317 * -1 to indicate no more domains are available.
320 vm_domain_iterator_run(struct vm_domain_iterator *vi, int *domain)
323 /* General catch-all */
327 switch (vi->policy) {
328 case VM_POLICY_FIXED_DOMAIN:
329 case VM_POLICY_FIRST_TOUCH:
330 *domain = vi->domain;
333 case VM_POLICY_FIXED_DOMAIN_ROUND_ROBIN:
334 case VM_POLICY_FIRST_TOUCH_ROUND_ROBIN:
336 * XXX TODO: skip over the rr'ed domain
337 * if it equals the one we started with.
339 if (vi->n == vm_ndomains)
340 *domain = vi->domain;
342 *domain = vm_domain_rr_selectdomain();
345 case VM_POLICY_ROUND_ROBIN:
347 *domain = vm_domain_rr_selectdomain();
356 * Returns 1 if the iteration is done, or 0 if it has not.
358 * This can only be called after at least one loop through
359 * the iterator. Ie, it's designed to be used as a tail
360 * check of a loop, not the head check of a loop.
363 vm_domain_iterator_isdone(struct vm_domain_iterator *vi)
370 vm_domain_iterator_cleanup(struct vm_domain_iterator *vi)