1 /*
2 * Copyright (c) 1997, 1998 John S. Dyson. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice immediately at the beginning of the file, without modification,
9 * this list of conditions, and the following disclaimer.
10 * 2. Absolutely no warranty of function or purpose is made by the author
11 * John S. Dyson.
12 *
13 * $FreeBSD: src/sys/vm/vm_zone.c,v 1.30.2.6 2002/10/10 19:50:16 dillon Exp $
14 *
15 * Copyright (c) 2003-2017,2019 The DragonFly Project. All rights reserved.
16 *
17 * This code is derived from software contributed to The DragonFly Project
18 * by Matthew Dillon <dillon@backplane.com>
19 *
20 * Redistribution and use in source and binary forms, with or without
21 * modification, are permitted provided that the following conditions
22 * are met:
23 *
24 * 1. Redistributions of source code must retain the above copyright
25 * notice, this list of conditions and the following disclaimer.
26 * 2. Redistributions in binary form must reproduce the above copyright
27 * notice, this list of conditions and the following disclaimer in
28 * the documentation and/or other materials provided with the
29 * distribution.
30 * 3. Neither the name of The DragonFly Project nor the names of its
31 * contributors may be used to endorse or promote products derived
32 * from this software without specific, prior written permission.
33 *
34 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
35 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
36 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
37 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
38 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
39 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
40 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
41 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
42 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
43 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
44 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
45 * SUCH DAMAGE.
46 */
47
48 #include <sys/param.h>
49 #include <sys/queue.h>
50 #include <sys/systm.h>
51 #include <sys/kernel.h>
52 #include <sys/lock.h>
53 #include <sys/malloc.h>
54 #include <sys/sysctl.h>
55 #include <sys/vmmeter.h>
56
57 #include <vm/vm.h>
58 #include <vm/vm_object.h>
59 #include <vm/vm_page.h>
60 #include <vm/vm_map.h>
61 #include <vm/vm_kern.h>
62 #include <vm/vm_extern.h>
63 #include <vm/vm_zone.h>
64
65 #include <sys/spinlock2.h>
66 #include <vm/vm_page2.h>
67
68 static MALLOC_DEFINE(M_ZONE, "ZONE", "Zone header");
69
70 #define ZONE_ERROR_INVALID 0
71 #define ZONE_ERROR_NOTFREE 1
72 #define ZONE_ERROR_ALREADYFREE 2
73
74 #define ZONE_ROUNDING 32
75
76 #define ZENTRY_FREE 0x12342378
77
78 long zone_burst = 128;
79
80 static void *zget(vm_zone_t z, int *tryagainp);
81
82 /*
83 * Return an item from the specified zone. This function is non-blocking for
84 * ZONE_INTERRUPT zones.
85 *
86 * No requirements.
87 */
88 void *
zalloc(vm_zone_t z)89 zalloc(vm_zone_t z)
90 {
91 globaldata_t gd = mycpu;
92 vm_zpcpu_t *zpcpu;
93 void *item;
94 int tryagain;
95 long n;
96
97 #ifdef INVARIANTS
98 if (z == NULL)
99 zerror(ZONE_ERROR_INVALID);
100 #endif
101 zpcpu = &z->zpcpu[gd->gd_cpuid];
102 retry:
103 /*
104 * Avoid spinlock contention by allocating from a per-cpu queue
105 */
106 if (zpcpu->zfreecnt > 0) {
107 crit_enter_gd(gd);
108 if (zpcpu->zfreecnt > 0) {
109 item = zpcpu->zitems;
110 #ifdef INVARIANTS
111 KASSERT(item != NULL,
112 ("zitems_pcpu unexpectedly NULL"));
113 if (((void **)item)[1] != (void *)ZENTRY_FREE)
114 zerror(ZONE_ERROR_NOTFREE);
115 ((void **)item)[1] = NULL;
116 #endif
117 zpcpu->zitems = ((void **) item)[0];
118 --zpcpu->zfreecnt;
119 ++zpcpu->znalloc;
120 crit_exit_gd(gd);
121
122 return item;
123 }
124 crit_exit_gd(gd);
125 }
126
127 /*
128 * Per-zone spinlock for the remainder. Always load at least one
129 * item.
130 */
131 spin_lock(&z->zspin);
132 if (z->zfreecnt > z->zfreemin) {
133 n = zone_burst;
134 do {
135 item = z->zitems;
136 #ifdef INVARIANTS
137 KASSERT(item != NULL, ("zitems unexpectedly NULL"));
138 if (((void **)item)[1] != (void *)ZENTRY_FREE)
139 zerror(ZONE_ERROR_NOTFREE);
140 #endif
141 z->zitems = ((void **)item)[0];
142 --z->zfreecnt;
143 ((void **)item)[0] = zpcpu->zitems;
144 zpcpu->zitems = item;
145 ++zpcpu->zfreecnt;
146 } while (--n > 0 && z->zfreecnt > z->zfreemin);
147 spin_unlock(&z->zspin);
148 goto retry;
149 } else {
150 spin_unlock(&z->zspin);
151 tryagain = 0;
152 item = zget(z, &tryagain);
153 if (tryagain)
154 goto retry;
155
156 /*
157 * PANICFAIL allows the caller to assume that the zalloc()
158 * will always succeed. If it doesn't, we panic here.
159 */
160 if (item == NULL && (z->zflags & ZONE_PANICFAIL))
161 panic("zalloc(%s) failed", z->zname);
162 }
163 return item;
164 }
165
166 /*
167 * Free an item to the specified zone.
168 *
169 * No requirements.
170 */
171 void
zfree(vm_zone_t z,void * item)172 zfree(vm_zone_t z, void *item)
173 {
174 globaldata_t gd = mycpu;
175 vm_zpcpu_t *zpcpu;
176 void *tail_item;
177 long count;
178 long zmax;
179
180 zpcpu = &z->zpcpu[gd->gd_cpuid];
181
182 /*
183 * Avoid spinlock contention by freeing into a per-cpu queue
184 */
185 zmax = z->zmax_pcpu;
186 if (zmax < 1024)
187 zmax = 1024;
188
189 /*
190 * Add to pcpu cache
191 */
192 crit_enter_gd(gd);
193 ((void **)item)[0] = zpcpu->zitems;
194 #ifdef INVARIANTS
195 if (((void **)item)[1] == (void *)ZENTRY_FREE)
196 zerror(ZONE_ERROR_ALREADYFREE);
197 ((void **)item)[1] = (void *)ZENTRY_FREE;
198 #endif
199 zpcpu->zitems = item;
200 ++zpcpu->zfreecnt;
201
202 if (zpcpu->zfreecnt < zmax) {
203 crit_exit_gd(gd);
204 return;
205 }
206
207 /*
208 * Hystereis, move (zmax) (calculated below) items to the pool.
209 */
210 zmax = zmax / 2;
211 if (zmax > zone_burst)
212 zmax = zone_burst;
213 tail_item = item;
214 count = 1;
215
216 while (count < zmax) {
217 tail_item = ((void **)tail_item)[0];
218 ++count;
219 }
220 zpcpu->zitems = ((void **)tail_item)[0];
221 zpcpu->zfreecnt -= count;
222
223 /*
224 * Per-zone spinlock for the remainder.
225 *
226 * Also implement hysteresis by freeing a number of pcpu
227 * entries.
228 */
229 spin_lock(&z->zspin);
230 ((void **)tail_item)[0] = z->zitems;
231 z->zitems = item;
232 z->zfreecnt += count;
233 spin_unlock(&z->zspin);
234
235 crit_exit_gd(gd);
236 }
237
238 /*
239 * This file comprises a very simple zone allocator. This is used
240 * in lieu of the malloc allocator, where needed or more optimal.
241 *
242 * Note that the initial implementation of this had coloring, and
243 * absolutely no improvement (actually perf degradation) occurred.
244 *
245 * Note also that the zones are type stable. The only restriction is
246 * that the first two longwords of a data structure can be changed
247 * between allocations. Any data that must be stable between allocations
248 * must reside in areas after the first two longwords.
249 *
250 * zinitna, zinit, zbootinit are the initialization routines.
251 * zalloc, zfree, are the allocation/free routines.
252 */
253
254 LIST_HEAD(zlist, vm_zone) zlist = LIST_HEAD_INITIALIZER(zlist);
255 static int sysctl_vm_zone(SYSCTL_HANDLER_ARGS);
256 static vm_pindex_t zone_kmem_pages, zone_kern_pages;
257 static long zone_kmem_kvaspace;
258
259 /*
260 * Create a zone, but don't allocate the zone structure. If the
261 * zone had been previously created by the zone boot code, initialize
262 * various parts of the zone code.
263 *
264 * If waits are not allowed during allocation (e.g. during interrupt
265 * code), a-priori allocate the kernel virtual space, and allocate
266 * only pages when needed.
267 *
268 * Arguments:
269 * z pointer to zone structure.
270 * obj pointer to VM object (opt).
271 * name name of zone.
272 * size size of zone entries.
273 * nentries number of zone entries allocated (only ZONE_INTERRUPT.)
274 * flags ZONE_INTERRUPT -- items can be allocated at interrupt time.
275 * zalloc number of pages allocated when memory is needed.
276 *
277 * Note that when using ZONE_INTERRUPT, the size of the zone is limited
278 * by the nentries argument. The size of the memory allocatable is
279 * unlimited if ZONE_INTERRUPT is not set.
280 *
281 * No requirements.
282 */
283 int
zinitna(vm_zone_t z,char * name,size_t size,long nentries,uint32_t flags)284 zinitna(vm_zone_t z, char *name, size_t size, long nentries, uint32_t flags)
285 {
286 size_t totsize;
287
288 /*
289 * Only zones created with zinit() are destroyable.
290 */
291 if (z->zflags & ZONE_DESTROYABLE)
292 panic("zinitna: can't create destroyable zone");
293
294 /*
295 * NOTE: We can only adjust zsize if we previously did not
296 * use zbootinit().
297 */
298 if ((z->zflags & ZONE_BOOT) == 0) {
299 z->zsize = roundup2(size, ZONE_ROUNDING);
300 spin_init(&z->zspin, "zinitna");
301 lockinit(&z->zgetlk, "zgetlk", 0, LK_CANRECURSE);
302
303 z->zfreecnt = 0;
304 z->ztotal = 0;
305 z->zmax = 0;
306 z->zname = name;
307 z->zitems = NULL;
308
309 lwkt_gettoken(&vm_token);
310 LIST_INSERT_HEAD(&zlist, z, zlink);
311 lwkt_reltoken(&vm_token);
312
313 bzero(z->zpcpu, sizeof(z->zpcpu));
314 }
315
316 z->zkmvec = NULL;
317 z->zkmcur = z->zkmmax = 0;
318 z->zflags |= flags;
319
320 /*
321 * If we cannot wait, allocate KVA space up front, and we will fill
322 * in pages as needed. This is particularly required when creating
323 * an allocation space for map entries in kernel_map, because we
324 * do not want to go into a recursion deadlock with
325 * vm_map_entry_reserve().
326 */
327 if (z->zflags & ZONE_INTERRUPT) {
328 totsize = round_page((size_t)z->zsize * nentries);
329 atomic_add_long(&zone_kmem_kvaspace, totsize);
330
331 z->zkva = kmem_alloc_pageable(kernel_map, totsize,
332 VM_SUBSYS_ZALLOC);
333 if (z->zkva == 0) {
334 LIST_REMOVE(z, zlink);
335 return 0;
336 }
337
338 z->zpagemax = totsize / PAGE_SIZE;
339 z->zallocflag = VM_ALLOC_SYSTEM | VM_ALLOC_INTERRUPT |
340 VM_ALLOC_NORMAL | VM_ALLOC_RETRY;
341 z->zmax += nentries;
342
343 /*
344 * Set reasonable pcpu cache bounds. Low-memory systems
345 * might try to cache too little, large-memory systems
346 * might try to cache more than necessarsy.
347 *
348 * In particular, pvzone can wind up being excessive and
349 * waste memory unnecessarily.
350 */
351 z->zmax_pcpu = z->zmax / ncpus / 64;
352 if (z->zmax_pcpu < 1024)
353 z->zmax_pcpu = 1024;
354 if (z->zmax_pcpu * z->zsize > 16*1024*1024)
355 z->zmax_pcpu = 16*1024*1024 / z->zsize;
356 } else {
357 z->zallocflag = VM_ALLOC_NORMAL | VM_ALLOC_SYSTEM;
358 z->zmax = 0;
359 z->zmax_pcpu = 8192;
360 }
361
362
363 if (z->zsize > PAGE_SIZE)
364 z->zfreemin = 1;
365 else
366 z->zfreemin = PAGE_SIZE / z->zsize;
367
368 z->zpagecount = 0;
369
370 /*
371 * Reduce kernel_map spam by allocating in chunks.
372 */
373 z->zalloc = ZONE_MAXPGLOAD;
374
375 /*
376 * Populate the interrrupt zone at creation time rather than
377 * on first allocation, as this is a potentially long operation.
378 */
379 if (z->zflags & ZONE_INTERRUPT) {
380 void *buf;
381
382 buf = zget(z, NULL);
383 if (buf)
384 zfree(z, buf);
385 }
386
387 return 1;
388 }
389
390 /*
391 * Subroutine same as zinitna, except zone data structure is allocated
392 * automatically by malloc. This routine should normally be used, except
393 * in certain tricky startup conditions in the VM system -- then
394 * zbootinit and zinitna can be used. Zinit is the standard zone
395 * initialization call.
396 *
397 * No requirements.
398 */
399 vm_zone_t
zinit(char * name,size_t size,long nentries,uint32_t flags)400 zinit(char *name, size_t size, long nentries, uint32_t flags)
401 {
402 vm_zone_t z;
403
404 z = (vm_zone_t) kmalloc(sizeof (struct vm_zone), M_ZONE, M_NOWAIT);
405 if (z == NULL)
406 return NULL;
407
408 z->zflags = 0;
409 if (zinitna(z, name, size, nentries, flags & ~ZONE_DESTROYABLE) == 0) {
410 kfree(z, M_ZONE);
411 return NULL;
412 }
413
414 if (flags & ZONE_DESTROYABLE)
415 z->zflags |= ZONE_DESTROYABLE;
416
417 return z;
418 }
419
420 /*
421 * Initialize a zone before the system is fully up. This routine should
422 * only be called before full VM startup.
423 *
424 * Called from the low level boot code only.
425 */
426 void
zbootinit(vm_zone_t z,char * name,size_t size,void * item,long nitems)427 zbootinit(vm_zone_t z, char *name, size_t size, void *item, long nitems)
428 {
429 long i;
430
431 spin_init(&z->zspin, "zbootinit");
432 lockinit(&z->zgetlk, "zgetlk", 0, LK_CANRECURSE);
433 bzero(z->zpcpu, sizeof(z->zpcpu));
434 z->zname = name;
435 z->zsize = size;
436 z->zpagemax = 0;
437 z->zflags = ZONE_BOOT;
438 z->zfreemin = 0;
439 z->zallocflag = 0;
440 z->zpagecount = 0;
441 z->zalloc = 0;
442
443 bzero(item, (size_t)nitems * z->zsize);
444 z->zitems = NULL;
445 for (i = 0; i < nitems; i++) {
446 ((void **)item)[0] = z->zitems;
447 #ifdef INVARIANTS
448 ((void **)item)[1] = (void *)ZENTRY_FREE;
449 #endif
450 z->zitems = item;
451 item = (uint8_t *)item + z->zsize;
452 }
453 z->zfreecnt = nitems;
454 z->zmax = nitems;
455 z->ztotal = nitems;
456
457 lwkt_gettoken(&vm_token);
458 LIST_INSERT_HEAD(&zlist, z, zlink);
459 lwkt_reltoken(&vm_token);
460 }
461
462 /*
463 * Release all resources owned by zone created with zinit().
464 *
465 * No requirements.
466 */
467 void
zdestroy(vm_zone_t z)468 zdestroy(vm_zone_t z)
469 {
470 vm_pindex_t i;
471
472 if (z == NULL)
473 panic("zdestroy: null zone");
474 if ((z->zflags & ZONE_DESTROYABLE) == 0)
475 panic("zdestroy: undestroyable zone");
476
477 lwkt_gettoken(&vm_token);
478 LIST_REMOVE(z, zlink);
479 lwkt_reltoken(&vm_token);
480
481 /*
482 * Release virtual mappings, physical memory and update sysctl stats.
483 */
484 KKASSERT((z->zflags & ZONE_INTERRUPT) == 0);
485 for (i = 0; i < z->zkmcur; i++) {
486 kmem_free(kernel_map, z->zkmvec[i],
487 (size_t)z->zalloc * PAGE_SIZE);
488 atomic_subtract_long(&zone_kern_pages, z->zalloc);
489 }
490 if (z->zkmvec != NULL)
491 kfree(z->zkmvec, M_ZONE);
492
493 spin_uninit(&z->zspin);
494 kfree(z, M_ZONE);
495 }
496
497
498 /*
499 * void *zalloc(vm_zone_t zone) --
500 * Returns an item from a specified zone. May not be called from a
501 * FAST interrupt or IPI function.
502 *
503 * void zfree(vm_zone_t zone, void *item) --
504 * Frees an item back to a specified zone. May not be called from a
505 * FAST interrupt or IPI function.
506 */
507
508 /*
509 * Internal zone routine. Not to be called from external (non vm_zone) code.
510 *
511 * This function may return NULL.
512 *
513 * No requirements.
514 */
515 static void *
zget(vm_zone_t z,int * tryagainp)516 zget(vm_zone_t z, int *tryagainp)
517 {
518 vm_page_t pgs[ZONE_MAXPGLOAD];
519 vm_page_t m;
520 long nitems;
521 long savezpc;
522 size_t nbytes;
523 size_t noffset;
524 void *item;
525 vm_pindex_t npages;
526 vm_pindex_t nalloc;
527 vm_pindex_t i;
528
529 if (z == NULL)
530 panic("zget: null zone");
531
532 /*
533 * We need an encompassing per-zone lock for zget() refills.
534 *
535 * Without this we wind up locking on the vm_map inside kmem_alloc*()
536 * prior to any entries actually being added to the zone, potentially
537 * exhausting the per-cpu cache of vm_map_entry's when multiple threads
538 * are blocked on the same lock on the same cpu.
539 */
540 if ((z->zflags & ZONE_INTERRUPT) == 0) {
541 if (lockmgr(&z->zgetlk, LK_EXCLUSIVE | LK_SLEEPFAIL)) {
542 *tryagainp = 1;
543 return NULL;
544 }
545 }
546
547 if (z->zflags & ZONE_INTERRUPT) {
548 /*
549 * Interrupt zones do not mess with the kernel_map, they
550 * simply populate an existing mapping.
551 *
552 * First allocate as many pages as we can, stopping at
553 * our limit or if the page allocation fails. Try to
554 * avoid exhausting the interrupt free minimum by backing
555 * off to normal page allocations after a certain point.
556 */
557 for (i = 0; i < ZONE_MAXPGLOAD && i < z->zalloc; ++i) {
558 if (i < 4) {
559 m = vm_page_alloc(NULL,
560 mycpu->gd_rand_incr++,
561 z->zallocflag);
562 } else {
563 m = vm_page_alloc(NULL,
564 mycpu->gd_rand_incr++,
565 VM_ALLOC_NORMAL |
566 VM_ALLOC_SYSTEM);
567 }
568 if (m == NULL)
569 break;
570 pgs[i] = m;
571 }
572 nalloc = i;
573
574 /*
575 * Account for the pages.
576 *
577 * NOTE! Do not allow overlap with a prior page as it
578 * may still be undergoing allocation on another
579 * cpu.
580 */
581 spin_lock(&z->zspin);
582 noffset = (size_t)z->zpagecount * PAGE_SIZE;
583 /* noffset -= noffset % z->zsize; */
584 savezpc = z->zpagecount;
585
586 /*
587 * Track total memory use and kmem offset.
588 */
589 if (z->zpagecount + nalloc > z->zpagemax)
590 z->zpagecount = z->zpagemax;
591 else
592 z->zpagecount += nalloc;
593
594 item = (char *)z->zkva + noffset;
595 npages = z->zpagecount - savezpc;
596 nitems = ((size_t)(savezpc + npages) * PAGE_SIZE - noffset) /
597 z->zsize;
598 atomic_add_long(&zone_kmem_pages, npages);
599 spin_unlock(&z->zspin);
600
601 /*
602 * Enter the pages into the reserved KVA space.
603 */
604 for (i = 0; i < npages; ++i) {
605 vm_offset_t zkva;
606
607 m = pgs[i];
608 KKASSERT(m->queue == PQ_NONE);
609 m->valid = VM_PAGE_BITS_ALL;
610 vm_page_wire(m);
611 vm_page_wakeup(m);
612
613 zkva = z->zkva + (size_t)(savezpc + i) * PAGE_SIZE;
614 pmap_kenter(zkva, VM_PAGE_TO_PHYS(m));
615 bzero((void *)zkva, PAGE_SIZE);
616 }
617 for (i = npages; i < nalloc; ++i) {
618 m = pgs[i];
619 vm_page_free(m);
620 }
621 } else if (z->zflags & ZONE_SPECIAL) {
622 /*
623 * The special zone is the one used for vm_map_entry_t's.
624 * We have to avoid an infinite recursion in
625 * vm_map_entry_reserve() by using vm_map_entry_kreserve()
626 * instead. The map entries are pre-reserved by the kernel
627 * by vm_map_entry_reserve_cpu_init().
628 */
629 nbytes = (size_t)z->zalloc * PAGE_SIZE;
630 z->zpagecount += z->zalloc; /* Track total memory use */
631
632 item = (void *)kmem_alloc3(kernel_map, nbytes,
633 VM_SUBSYS_ZALLOC, KM_KRESERVE);
634
635 /* note: z might be modified due to blocking */
636 if (item != NULL) {
637 atomic_add_long(&zone_kern_pages, z->zalloc);
638 bzero(item, nbytes);
639 } else {
640 nbytes = 0;
641 }
642 nitems = nbytes / z->zsize;
643 } else {
644 /*
645 * Otherwise allocate KVA from the kernel_map.
646 */
647 nbytes = (size_t)z->zalloc * PAGE_SIZE;
648 z->zpagecount += z->zalloc; /* Track total memory use */
649
650 item = (void *)kmem_alloc3(kernel_map, nbytes,
651 VM_SUBSYS_ZALLOC, 0);
652
653 /* note: z might be modified due to blocking */
654 if (item != NULL) {
655 atomic_add_long(&zone_kern_pages, z->zalloc);
656 bzero(item, nbytes);
657
658 if (z->zflags & ZONE_DESTROYABLE) {
659 if (z->zkmcur == z->zkmmax) {
660 z->zkmmax =
661 z->zkmmax==0 ? 1 : z->zkmmax*2;
662 z->zkmvec = krealloc(z->zkmvec,
663 z->zkmmax * sizeof(z->zkmvec[0]),
664 M_ZONE, M_WAITOK);
665 }
666 z->zkmvec[z->zkmcur++] = (vm_offset_t)item;
667 }
668 } else {
669 nbytes = 0;
670 }
671 nitems = nbytes / z->zsize;
672 }
673
674 /*
675 * Enter any new pages into the pool, reserving one, or get the
676 * item from the existing pool.
677 */
678 spin_lock(&z->zspin);
679 z->ztotal += nitems;
680
681 /*
682 * The zone code may need to allocate kernel memory, which can
683 * recurse zget() infinitely if we do not handle it properly.
684 * We deal with this by directly repopulating the pcpu vm_map_entry
685 * cache.
686 */
687 if (nitems > 1 && (z->zflags & ZONE_SPECIAL)) {
688 struct globaldata *gd = mycpu;
689 vm_map_entry_t entry;
690
691 /*
692 * Make sure we have enough structures in gd_vme_base to handle
693 * the reservation request.
694 *
695 * The critical section protects access to the per-cpu gd.
696 */
697 crit_enter();
698 while (gd->gd_vme_avail < 2 && nitems > 1) {
699 entry = item;
700 MAPENT_FREELIST(entry) = gd->gd_vme_base;
701 gd->gd_vme_base = entry;
702 atomic_add_int(&gd->gd_vme_avail, 1);
703 item = (uint8_t *)item + z->zsize;
704 --nitems;
705 }
706 crit_exit();
707 }
708
709 if (nitems != 0) {
710 /*
711 * Enter pages into the pool saving one for immediate
712 * allocation.
713 */
714 nitems -= 1;
715 for (i = 0; i < nitems; i++) {
716 ((void **)item)[0] = z->zitems;
717 #ifdef INVARIANTS
718 ((void **)item)[1] = (void *)ZENTRY_FREE;
719 #endif
720 z->zitems = item;
721 item = (uint8_t *)item + z->zsize;
722 }
723 z->zfreecnt += nitems;
724 ++z->znalloc;
725 } else if (z->zfreecnt > 0) {
726 /*
727 * Get an item from the existing pool.
728 */
729 item = z->zitems;
730 z->zitems = ((void **)item)[0];
731 #ifdef INVARIANTS
732 if (((void **)item)[1] != (void *)ZENTRY_FREE)
733 zerror(ZONE_ERROR_NOTFREE);
734 ((void **) item)[1] = NULL;
735 #endif
736 --z->zfreecnt;
737 ++z->znalloc;
738 } else {
739 /*
740 * No items available.
741 */
742 item = NULL;
743 }
744 spin_unlock(&z->zspin);
745
746 /*
747 * Release the per-zone global lock after the items have been
748 * added. Any other threads blocked in zget()'s zgetlk will
749 * then retry rather than potentially exhaust the per-cpu cache
750 * of vm_map_entry structures doing their own kmem_alloc() calls,
751 * or allocating excessive amounts of space unnecessarily.
752 */
753 if ((z->zflags & ZONE_INTERRUPT) == 0)
754 lockmgr(&z->zgetlk, LK_RELEASE);
755
756 return item;
757 }
758
759 /*
760 * No requirements.
761 */
762 static int
sysctl_vm_zone(SYSCTL_HANDLER_ARGS)763 sysctl_vm_zone(SYSCTL_HANDLER_ARGS)
764 {
765 vm_zone_t curzone;
766 char tmpbuf[128];
767 char tmpname[14];
768 int error = 0;
769
770 ksnprintf(tmpbuf, sizeof(tmpbuf),
771 "\nITEM SIZE LIMIT USED FREE REQUESTS\n");
772 error = SYSCTL_OUT(req, tmpbuf, strlen(tmpbuf));
773 if (error)
774 return (error);
775
776 lwkt_gettoken(&vm_token);
777 LIST_FOREACH(curzone, &zlist, zlink) {
778 size_t i;
779 size_t len;
780 int offset;
781 long freecnt;
782 long znalloc;
783 int n;
784
785 len = strlen(curzone->zname);
786 if (len >= (sizeof(tmpname) - 1))
787 len = (sizeof(tmpname) - 1);
788 for(i = 0; i < sizeof(tmpname) - 1; i++)
789 tmpname[i] = ' ';
790 tmpname[i] = 0;
791 memcpy(tmpname, curzone->zname, len);
792 tmpname[len] = ':';
793 offset = 0;
794 if (curzone == LIST_FIRST(&zlist)) {
795 offset = 1;
796 tmpbuf[0] = '\n';
797 }
798 freecnt = curzone->zfreecnt;
799 znalloc = curzone->znalloc;
800 for (n = 0; n < ncpus; ++n) {
801 freecnt += curzone->zpcpu[n].zfreecnt;
802 znalloc += curzone->zpcpu[n].znalloc;
803 }
804
805 ksnprintf(tmpbuf + offset, sizeof(tmpbuf) - offset,
806 "%s %6.6lu, %8.8lu, %6.6lu, %6.6lu, %8.8lu\n",
807 tmpname, curzone->zsize, curzone->zmax,
808 (curzone->ztotal - freecnt),
809 freecnt, znalloc);
810
811 len = strlen((char *)tmpbuf);
812 if (LIST_NEXT(curzone, zlink) == NULL)
813 tmpbuf[len - 1] = 0;
814
815 error = SYSCTL_OUT(req, tmpbuf, len);
816
817 if (error)
818 break;
819 }
820 lwkt_reltoken(&vm_token);
821 return (error);
822 }
823
824 #if defined(INVARIANTS)
825
826 /*
827 * Debugging only.
828 */
829 void
zerror(int error)830 zerror(int error)
831 {
832 char *msg;
833
834 switch (error) {
835 case ZONE_ERROR_INVALID:
836 msg = "zone: invalid zone";
837 break;
838 case ZONE_ERROR_NOTFREE:
839 msg = "zone: entry not free";
840 break;
841 case ZONE_ERROR_ALREADYFREE:
842 msg = "zone: freeing free entry";
843 break;
844 default:
845 msg = "zone: invalid error";
846 break;
847 }
848 panic("%s", msg);
849 }
850 #endif
851
852 SYSCTL_OID(_vm, OID_AUTO, zone, CTLTYPE_STRING|CTLFLAG_RD, \
853 NULL, 0, sysctl_vm_zone, "A", "Zone Info");
854
855 SYSCTL_LONG(_vm, OID_AUTO, zone_kmem_pages,
856 CTLFLAG_RD, &zone_kmem_pages, 0, "Number of interrupt safe pages allocated by zone");
857 SYSCTL_LONG(_vm, OID_AUTO, zone_burst,
858 CTLFLAG_RW, &zone_burst, 0, "Burst from depot to pcpu cache");
859 SYSCTL_LONG(_vm, OID_AUTO, zone_kmem_kvaspace,
860 CTLFLAG_RD, &zone_kmem_kvaspace, 0, "KVA space allocated by zone");
861 SYSCTL_LONG(_vm, OID_AUTO, zone_kern_pages,
862 CTLFLAG_RD, &zone_kern_pages, 0, "Number of non-interrupt safe pages allocated by zone");
863