FreeBSD/Linux Kernel Cross Reference
sys/uvm/uvm_pglist.c
1 /* $NetBSD: uvm_pglist.c,v 1.31 2004/03/24 07:47:33 junyoung Exp $ */
2
3 /*-
4 * Copyright (c) 1997 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9 * NASA Ames Research Center.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the NetBSD
22 * Foundation, Inc. and its contributors.
23 * 4. Neither the name of The NetBSD Foundation nor the names of its
24 * contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37 * POSSIBILITY OF SUCH DAMAGE.
38 */
39
40 /*
41 * uvm_pglist.c: pglist functions
42 */
43
44 #include <sys/cdefs.h>
45 __KERNEL_RCSID(0, "$NetBSD: uvm_pglist.c,v 1.31 2004/03/24 07:47:33 junyoung Exp $");
46
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/malloc.h>
50 #include <sys/proc.h>
51
52 #include <uvm/uvm.h>
53
54 #ifdef VM_PAGE_ALLOC_MEMORY_STATS
55 #define STAT_INCR(v) (v)++
56 #define STAT_DECR(v) do { \
57 if ((v) == 0) \
58 printf("%s:%d -- Already 0!\n", __FILE__, __LINE__); \
59 else \
60 (v)--; \
61 } while (/*CONSTCOND*/ 0)
62 u_long uvm_pglistalloc_npages;
63 #else
64 #define STAT_INCR(v)
65 #define STAT_DECR(v)
66 #endif
67
68 /*
69 * uvm_pglistalloc: allocate a list of pages
70 *
71 * => allocated pages are placed onto an rlist. rlist is
72 * initialized by uvm_pglistalloc.
73 * => returns 0 on success or errno on failure
74 * => implementation allocates a single segment if any constraints are
75 * imposed by call arguments.
76 * => doesn't take into account clean non-busy pages on inactive list
77 * that could be used(?)
78 * => params:
79 * size the size of the allocation, rounded to page size.
80 * low the low address of the allowed allocation range.
81 * high the high address of the allowed allocation range.
82 * alignment memory must be aligned to this power-of-two boundary.
83 * boundary no segment in the allocation may cross this
84 * power-of-two boundary (relative to zero).
85 */
86
87 static void uvm_pglist_add(struct vm_page *, struct pglist *);
88 static int uvm_pglistalloc_c_ps(struct vm_physseg *, int, paddr_t, paddr_t,
89 paddr_t, paddr_t, struct pglist *);
90 static int uvm_pglistalloc_contig(int, paddr_t, paddr_t, paddr_t, paddr_t,
91 struct pglist *);
92 static int uvm_pglistalloc_s_ps(struct vm_physseg *, int, paddr_t, paddr_t,
93 struct pglist *);
94 static int uvm_pglistalloc_simple(int, paddr_t, paddr_t,
95 struct pglist *, int);
96
97 static void
98 uvm_pglist_add(pg, rlist)
99 struct vm_page *pg;
100 struct pglist *rlist;
101 {
102 int free_list, color, pgflidx;
103 #ifdef DEBUG
104 struct vm_page *tp;
105 #endif
106
107 #if PGFL_NQUEUES != 2
108 #error uvm_pglistalloc needs to be updated
109 #endif
110
111 free_list = uvm_page_lookup_freelist(pg);
112 color = VM_PGCOLOR_BUCKET(pg);
113 pgflidx = (pg->flags & PG_ZERO) ? PGFL_ZEROS : PGFL_UNKNOWN;
114 #ifdef DEBUG
115 for (tp = TAILQ_FIRST(&uvm.page_free[
116 free_list].pgfl_buckets[color].pgfl_queues[pgflidx]);
117 tp != NULL;
118 tp = TAILQ_NEXT(tp, pageq)) {
119 if (tp == pg)
120 break;
121 }
122 if (tp == NULL)
123 panic("uvm_pglistalloc: page not on freelist");
124 #endif
125 TAILQ_REMOVE(&uvm.page_free[free_list].pgfl_buckets[
126 color].pgfl_queues[pgflidx], pg, pageq);
127 uvmexp.free--;
128 if (pg->flags & PG_ZERO)
129 uvmexp.zeropages--;
130 pg->flags = PG_CLEAN;
131 pg->pqflags = 0;
132 pg->uobject = NULL;
133 pg->uanon = NULL;
134 TAILQ_INSERT_TAIL(rlist, pg, pageq);
135 STAT_INCR(uvm_pglistalloc_npages);
136 }
137
138 static int
139 uvm_pglistalloc_c_ps(ps, num, low, high, alignment, boundary, rlist)
140 struct vm_physseg *ps;
141 int num;
142 paddr_t low, high, alignment, boundary;
143 struct pglist *rlist;
144 {
145 int try, limit, tryidx, end, idx;
146 struct vm_page *pgs;
147 int pagemask;
148 #ifdef DEBUG
149 paddr_t idxpa, lastidxpa;
150 int cidx;
151 #endif
152 #ifdef PGALLOC_VERBOSE
153 printf("pgalloc: contig %d pgs from psi %ld\n", num,
154 (long)(ps - vm_physmem));
155 #endif
156
157 try = roundup(max(atop(low), ps->avail_start), atop(alignment));
158 limit = min(atop(high), ps->avail_end);
159 pagemask = ~((boundary >> PAGE_SHIFT) - 1);
160
161 for (;;) {
162 if (try + num > limit) {
163 /*
164 * We've run past the allowable range.
165 */
166 return (0); /* FAIL */
167 }
168 if (boundary != 0 &&
169 ((try ^ (try + num - 1)) & pagemask) != 0) {
170 /*
171 * Region crosses boundary. Jump to the boundary
172 * just crossed and ensure alignment.
173 */
174 try = (try + num - 1) & pagemask;
175 try = roundup(try, atop(alignment));
176 continue;
177 }
178 #ifdef DEBUG
179 /*
180 * Make sure this is a managed physical page.
181 */
182
183 if (vm_physseg_find(try, &cidx) != ps - vm_physmem)
184 panic("pgalloc contig: botch1");
185 if (cidx != try - ps->start)
186 panic("pgalloc contig: botch2");
187 if (vm_physseg_find(try + num - 1, &cidx) != ps - vm_physmem)
188 panic("pgalloc contig: botch3");
189 if (cidx != try - ps->start + num - 1)
190 panic("pgalloc contig: botch4");
191 #endif
192 tryidx = try - ps->start;
193 end = tryidx + num;
194 pgs = ps->pgs;
195
196 /*
197 * Found a suitable starting page. See if the range is free.
198 */
199 for (idx = tryidx; idx < end; idx++) {
200 if (VM_PAGE_IS_FREE(&pgs[idx]) == 0)
201 break;
202
203 #ifdef DEBUG
204 idxpa = VM_PAGE_TO_PHYS(&pgs[idx]);
205 if (idx > tryidx) {
206 lastidxpa = VM_PAGE_TO_PHYS(&pgs[idx - 1]);
207 if ((lastidxpa + PAGE_SIZE) != idxpa) {
208 /*
209 * Region not contiguous.
210 */
211 panic("pgalloc contig: botch5");
212 }
213 if (boundary != 0 &&
214 ((lastidxpa ^ idxpa) & ~(boundary - 1))
215 != 0) {
216 /*
217 * Region crosses boundary.
218 */
219 panic("pgalloc contig: botch6");
220 }
221 }
222 #endif
223 }
224 if (idx == end)
225 break;
226
227 try += atop(alignment);
228 }
229
230 /*
231 * we have a chunk of memory that conforms to the requested constraints.
232 */
233 idx = tryidx;
234 while (idx < end)
235 uvm_pglist_add(&pgs[idx++], rlist);
236
237 #ifdef PGALLOC_VERBOSE
238 printf("got %d pgs\n", num);
239 #endif
240 return (num); /* number of pages allocated */
241 }
242
243 static int
244 uvm_pglistalloc_contig(num, low, high, alignment, boundary, rlist)
245 int num;
246 paddr_t low, high, alignment, boundary;
247 struct pglist *rlist;
248 {
249 int fl, psi;
250 struct vm_physseg *ps;
251 int s, error;
252
253 /* Default to "lose". */
254 error = ENOMEM;
255
256 /*
257 * Block all memory allocation and lock the free list.
258 */
259 s = uvm_lock_fpageq();
260
261 /* Are there even any free pages? */
262 if (uvmexp.free <= (uvmexp.reserve_pagedaemon + uvmexp.reserve_kernel))
263 goto out;
264
265 for (fl = 0; fl < VM_NFREELIST; fl++) {
266 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST)
267 for (psi = vm_nphysseg - 1 ; psi >= 0 ; psi--)
268 #else
269 for (psi = 0 ; psi < vm_nphysseg ; psi++)
270 #endif
271 {
272 ps = &vm_physmem[psi];
273
274 if (ps->free_list != fl)
275 continue;
276
277 num -= uvm_pglistalloc_c_ps(ps, num, low, high,
278 alignment, boundary, rlist);
279 if (num == 0) {
280 #ifdef PGALLOC_VERBOSE
281 printf("pgalloc: %lx-%lx\n",
282 VM_PAGE_TO_PHYS(TAILQ_FIRST(rlist)),
283 VM_PAGE_TO_PHYS(TAILQ_LAST(rlist)));
284 #endif
285 error = 0;
286 goto out;
287 }
288 }
289 }
290
291 out:
292 /*
293 * check to see if we need to generate some free pages waking
294 * the pagedaemon.
295 */
296
297 UVM_KICK_PDAEMON();
298 uvm_unlock_fpageq(s);
299 return (error);
300 }
301
302 static int
303 uvm_pglistalloc_s_ps(ps, num, low, high, rlist)
304 struct vm_physseg *ps;
305 int num;
306 paddr_t low, high;
307 struct pglist *rlist;
308 {
309 int todo, limit, try;
310 struct vm_page *pg;
311 #ifdef DEBUG
312 int cidx;
313 #endif
314 #ifdef PGALLOC_VERBOSE
315 printf("pgalloc: simple %d pgs from psi %ld\n", num,
316 (long)(ps - vm_physmem));
317 #endif
318
319 todo = num;
320 limit = min(atop(high), ps->avail_end);
321
322 for (try = max(atop(low), ps->avail_start);
323 try < limit; try ++) {
324 #ifdef DEBUG
325 if (vm_physseg_find(try, &cidx) != ps - vm_physmem)
326 panic("pgalloc simple: botch1");
327 if (cidx != (try - ps->start))
328 panic("pgalloc simple: botch2");
329 #endif
330 pg = &ps->pgs[try - ps->start];
331 if (VM_PAGE_IS_FREE(pg) == 0)
332 continue;
333
334 uvm_pglist_add(pg, rlist);
335 if (--todo == 0)
336 break;
337 }
338
339 #ifdef PGALLOC_VERBOSE
340 printf("got %d pgs\n", num - todo);
341 #endif
342 return (num - todo); /* number of pages allocated */
343 }
344
345 static int
346 uvm_pglistalloc_simple(num, low, high, rlist, waitok)
347 int num;
348 paddr_t low, high;
349 struct pglist *rlist;
350 int waitok;
351 {
352 int fl, psi, s, error;
353 struct vm_physseg *ps;
354
355 /* Default to "lose". */
356 error = ENOMEM;
357
358 again:
359 /*
360 * Block all memory allocation and lock the free list.
361 */
362 s = uvm_lock_fpageq();
363
364 /* Are there even any free pages? */
365 if (uvmexp.free <= (uvmexp.reserve_pagedaemon + uvmexp.reserve_kernel))
366 goto out;
367
368 for (fl = 0; fl < VM_NFREELIST; fl++) {
369 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST)
370 for (psi = vm_nphysseg - 1 ; psi >= 0 ; psi--)
371 #else
372 for (psi = 0 ; psi < vm_nphysseg ; psi++)
373 #endif
374 {
375 ps = &vm_physmem[psi];
376
377 if (ps->free_list != fl)
378 continue;
379
380 num -= uvm_pglistalloc_s_ps(ps, num, low, high, rlist);
381 if (num == 0) {
382 error = 0;
383 goto out;
384 }
385 }
386
387 }
388
389 out:
390 /*
391 * check to see if we need to generate some free pages waking
392 * the pagedaemon.
393 */
394
395 UVM_KICK_PDAEMON();
396 uvm_unlock_fpageq(s);
397 if (error) {
398 if (waitok) {
399 /* XXX perhaps some time limitation? */
400 #ifdef DEBUG
401 printf("pglistalloc waiting\n");
402 #endif
403 uvm_wait("pglalloc");
404 goto again;
405 } else
406 uvm_pglistfree(rlist);
407 }
408 #ifdef PGALLOC_VERBOSE
409 if (!error)
410 printf("pgalloc: %lx..%lx\n",
411 VM_PAGE_TO_PHYS(TAILQ_FIRST(rlist)),
412 VM_PAGE_TO_PHYS(TAILQ_LAST(rlist, pglist)));
413 #endif
414 return (error);
415 }
416
417 int
418 uvm_pglistalloc(size, low, high, alignment, boundary, rlist, nsegs, waitok)
419 psize_t size;
420 paddr_t low, high, alignment, boundary;
421 struct pglist *rlist;
422 int nsegs, waitok;
423 {
424 int num, res;
425
426 KASSERT((alignment & (alignment - 1)) == 0);
427 KASSERT((boundary & (boundary - 1)) == 0);
428
429 /*
430 * Our allocations are always page granularity, so our alignment
431 * must be, too.
432 */
433 if (alignment < PAGE_SIZE)
434 alignment = PAGE_SIZE;
435 if (boundary != 0 && boundary < size)
436 return (EINVAL);
437 num = atop(round_page(size));
438 low = roundup(low, alignment);
439
440 TAILQ_INIT(rlist);
441
442 if ((nsegs < size >> PAGE_SHIFT) || (alignment != PAGE_SIZE) ||
443 (boundary != 0))
444 res = uvm_pglistalloc_contig(num, low, high, alignment,
445 boundary, rlist);
446 else
447 res = uvm_pglistalloc_simple(num, low, high, rlist, waitok);
448
449 return (res);
450 }
451
452 /*
453 * uvm_pglistfree: free a list of pages
454 *
455 * => pages should already be unmapped
456 */
457
458 void
459 uvm_pglistfree(list)
460 struct pglist *list;
461 {
462 struct vm_page *pg;
463 int s;
464
465 /*
466 * Lock the free list and free each page.
467 */
468
469 s = uvm_lock_fpageq();
470 while ((pg = TAILQ_FIRST(list)) != NULL) {
471 boolean_t iszero;
472
473 KASSERT((pg->pqflags & (PQ_ACTIVE|PQ_INACTIVE)) == 0);
474 TAILQ_REMOVE(list, pg, pageq);
475 iszero = (pg->flags & PG_ZERO);
476 pg->pqflags = PQ_FREE;
477 #ifdef DEBUG
478 pg->uobject = (void *)0xdeadbeef;
479 pg->offset = 0xdeadbeef;
480 pg->uanon = (void *)0xdeadbeef;
481 #endif /* DEBUG */
482 #ifdef DEBUG
483 if (iszero)
484 uvm_pagezerocheck(pg);
485 #endif /* DEBUG */
486 TAILQ_INSERT_TAIL(&uvm.page_free[uvm_page_lookup_freelist(pg)].
487 pgfl_buckets[VM_PGCOLOR_BUCKET(pg)].
488 pgfl_queues[iszero ? PGFL_ZEROS : PGFL_UNKNOWN], pg, pageq);
489 uvmexp.free++;
490 if (iszero)
491 uvmexp.zeropages++;
492 if (uvmexp.zeropages < UVM_PAGEZERO_TARGET)
493 uvm.page_idle_zero = vm_page_zero_enable;
494 STAT_DECR(uvm_pglistalloc_npages);
495 }
496 uvm_unlock_fpageq(s);
497 }
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