kernel/vm: Remove some unused variables.
[dragonfly.git] / sys / vm / vm_swap.c
CommitLineData
984263bc 1/*
99ad9bc4
MD
2 * (MPSAFE)
3 *
984263bc
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4 * Copyright (c) 1982, 1986, 1989, 1993
5 * The Regents of the University of California. 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, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by the University of
18 * California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * @(#)vm_swap.c 8.5 (Berkeley) 2/17/94
36 * $FreeBSD: src/sys/vm/vm_swap.c,v 1.96.2.2 2001/10/14 18:46:47 iedowse Exp $
37 */
38
39#include "opt_swap.h"
40
41#include <sys/param.h>
42#include <sys/systm.h>
43#include <sys/sysproto.h>
44#include <sys/buf.h>
45#include <sys/proc.h>
895c1f85 46#include <sys/priv.h>
fad57d0e 47#include <sys/nlookup.h>
099f3e5e 48#include <sys/sysctl.h>
984263bc
MD
49#include <sys/dmap.h> /* XXX */
50#include <sys/vnode.h>
51#include <sys/fcntl.h>
52#include <sys/blist.h>
53#include <sys/kernel.h>
54#include <sys/lock.h>
55#include <sys/conf.h>
56#include <sys/stat.h>
684a93c4 57
984263bc
MD
58#include <vm/vm.h>
59#include <vm/vm_extern.h>
60#include <vm/swap_pager.h>
61#include <vm/vm_zone.h>
099f3e5e 62#include <vm/vm_param.h>
984263bc 63
684a93c4
MD
64#include <sys/thread2.h>
65#include <sys/mplock2.h>
99ad9bc4 66#include <sys/mutex2.h>
b12defdc 67#include <sys/spinlock2.h>
684a93c4 68
984263bc
MD
69/*
70 * Indirect driver for multi-controller paging.
71 */
72
73#ifndef NSWAPDEV
74#define NSWAPDEV 4
75#endif
76static struct swdevt should_be_malloced[NSWAPDEV];
460426e6 77struct swdevt *swdevt = should_be_malloced; /* exported to pstat/systat */
79634a66 78static swblk_t nswap; /* first block after the interleaved devs */
99ad9bc4 79static struct mtx swap_mtx = MTX_INITIALIZER;
460426e6 80int nswdev = NSWAPDEV; /* exported to pstat/systat */
984263bc 81int vm_swap_size;
1e5196f0 82int vm_swap_max;
984263bc 83
027193eb 84static int swapoff_one(int index);
984263bc
MD
85struct vnode *swapdev_vp;
86
87/*
99ad9bc4 88 * (struct vnode *a_vp, struct bio *b_bio)
984263bc 89 *
99ad9bc4
MD
90 * vn_strategy() for swapdev_vp. Perform swap strategy interleave device
91 * selection.
81b5c339 92 *
99ad9bc4 93 * No requirements.
984263bc 94 */
984263bc 95static int
81b5c339 96swapdev_strategy(struct vop_strategy_args *ap)
984263bc 97{
81b5c339
MD
98 struct bio *bio = ap->a_bio;
99 struct bio *nbio;
100 struct buf *bp = bio->bio_buf;
54078292 101 int sz, off, seg, index, blkno, nblkno;
5f910b2f 102 struct swdevt *sp;
984263bc 103 sz = howmany(bp->b_bcount, PAGE_SIZE);
54078292 104 blkno = (int)(bio->bio_offset >> PAGE_SHIFT);
984263bc
MD
105
106 /*
107 * Convert interleaved swap into per-device swap. Note that
108 * the block size is left in PAGE_SIZE'd chunks (for the newswap)
109 * here.
110 */
81b5c339 111 nbio = push_bio(bio);
984263bc 112 if (nswdev > 1) {
54078292 113 off = blkno % dmmax;
984263bc
MD
114 if (off + sz > dmmax) {
115 bp->b_error = EINVAL;
116 bp->b_flags |= B_ERROR;
81b5c339 117 biodone(bio);
984263bc
MD
118 return 0;
119 }
54078292 120 seg = blkno / dmmax;
984263bc
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121 index = seg % nswdev;
122 seg /= nswdev;
54078292 123 nbio->bio_offset = (off_t)(seg * dmmax + off) << PAGE_SHIFT;
984263bc
MD
124 } else {
125 index = 0;
54078292 126 nbio->bio_offset = bio->bio_offset;
984263bc 127 }
54078292 128 nblkno = (int)(nbio->bio_offset >> PAGE_SHIFT);
984263bc 129 sp = &swdevt[index];
54078292 130 if (nblkno + sz > sp->sw_nblks) {
984263bc
MD
131 bp->b_error = EINVAL;
132 bp->b_flags |= B_ERROR;
81b5c339
MD
133 /* I/O was never started on nbio, must biodone(bio) */
134 biodone(bio);
984263bc
MD
135 return 0;
136 }
984263bc
MD
137 if (sp->sw_vp == NULL) {
138 bp->b_error = ENODEV;
139 bp->b_flags |= B_ERROR;
81b5c339
MD
140 /* I/O was never started on nbio, must biodone(bio) */
141 biodone(bio);
984263bc
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142 return 0;
143 }
144
145 /*
81b5c339
MD
146 * Issue a strategy call on the appropriate swap vnode. Note that
147 * bp->b_vp is not modified. Strategy code is always supposed to
148 * use the passed vp.
149 *
c34665ce
MD
150 * We have to use vn_strategy() here even if we know we have a
151 * device in order to properly break up requests which exceed the
152 * device's DMA limits.
984263bc 153 */
81b5c339 154 vn_strategy(sp->sw_vp, nbio);
984263bc
MD
155 return 0;
156}
157
9f3543c6
MD
158static int
159swapdev_inactive(struct vop_inactive_args *ap)
160{
161 vrecycle(ap->a_vp);
162 return(0);
163}
164
165static int
166swapdev_reclaim(struct vop_reclaim_args *ap)
167{
168 return(0);
169}
170
984263bc
MD
171/*
172 * Create a special vnode op vector for swapdev_vp - we only use
81b5c339 173 * vn_strategy(), everything else returns an error.
984263bc 174 */
66a1ddf5
MD
175static struct vop_ops swapdev_vnode_vops = {
176 .vop_default = vop_defaultop,
9f3543c6
MD
177 .vop_strategy = swapdev_strategy,
178 .vop_inactive = swapdev_inactive,
179 .vop_reclaim = swapdev_reclaim
984263bc 180};
66a1ddf5 181static struct vop_ops *swapdev_vnode_vops_p = &swapdev_vnode_vops;
984263bc 182
66a1ddf5 183VNODEOP_SET(swapdev_vnode_vops);
984263bc
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184
185/*
41c20dac
MD
186 * swapon_args(char *name)
187 *
984263bc
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188 * System call swapon(name) enables swapping on device name,
189 * which must be in the swdevsw. Return EBUSY
190 * if already swapping on this device.
3919ced0 191 *
99ad9bc4 192 * No requirements.
984263bc 193 */
984263bc 194int
753fd850 195sys_swapon(struct swapon_args *uap)
984263bc 196{
dadab5e9 197 struct thread *td = curthread;
984263bc 198 struct vattr attr;
5f910b2f 199 struct vnode *vp;
fad57d0e 200 struct nlookupdata nd;
984263bc 201 int error;
dadab5e9 202
895c1f85 203 error = priv_check(td, PRIV_ROOT);
984263bc
MD
204 if (error)
205 return (error);
206
99ad9bc4 207 mtx_lock(&swap_mtx);
3919ced0 208 get_mplock();
fad57d0e
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209 vp = NULL;
210 error = nlookup_init(&nd, uap->name, UIO_USERSPACE, NLC_FOLLOW);
211 if (error == 0)
212 error = nlookup(&nd);
213 if (error == 0)
28623bf9 214 error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp);
fad57d0e 215 nlookup_done(&nd);
3919ced0
MD
216 if (error) {
217 rel_mplock();
99ad9bc4 218 mtx_unlock(&swap_mtx);
984263bc 219 return (error);
3919ced0 220 }
984263bc 221
3919ced0 222 if (vn_isdisk(vp, &error)) {
e4c9c0c8 223 error = swaponvp(td, vp, 0);
3919ced0
MD
224 } else if (vp->v_type == VREG && vp->v_tag == VT_NFS &&
225 (error = VOP_GETATTR(vp, &attr)) == 0) {
984263bc
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226 /*
227 * Allow direct swapping to NFS regular files in the same
228 * way that nfs_mountroot() sets up diskless swapping.
229 */
e4c9c0c8 230 error = swaponvp(td, vp, attr.va_size / DEV_BSIZE);
984263bc 231 }
984263bc
MD
232 if (error)
233 vrele(vp);
3919ced0 234 rel_mplock();
99ad9bc4 235 mtx_unlock(&swap_mtx);
984263bc
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236
237 return (error);
238}
239
240/*
241 * Swfree(index) frees the index'th portion of the swap map.
242 * Each of the nswdev devices provides 1/nswdev'th of the swap
243 * space, which is laid out with blocks of dmmax pages circularly
244 * among the devices.
245 *
246 * The new swap code uses page-sized blocks. The old swap code used
247 * DEV_BSIZE'd chunks.
248 *
249 * XXX locking when multiple swapon's run in parallel
250 */
251int
79634a66 252swaponvp(struct thread *td, struct vnode *vp, u_quad_t nblks)
984263bc 253{
79634a66 254 swblk_t aligned_nblks;
e0fc5693 255 int64_t dpsize;
e4c9c0c8 256 struct ucred *cred;
5f910b2f
RG
257 struct swdevt *sp;
258 swblk_t vsbase;
984263bc 259 swblk_t dvbase;
b13267a5 260 cdev_t dev;
e4c9c0c8 261 int index;
984263bc 262 int error;
9f3543c6 263 swblk_t blk;
dadab5e9 264
9910d07b 265 cred = td->td_ucred;
984263bc 266
138b6cd2 267 lwkt_gettoken(&vm_token); /* needed for vm_swap_size and blist */
99ad9bc4
MD
268 mtx_lock(&swap_mtx);
269
984263bc 270 if (!swapdev_vp) {
66a1ddf5 271 error = getspecialvnode(VT_NON, NULL, &swapdev_vnode_vops_p,
3446c007 272 &swapdev_vp, 0, 0);
984263bc
MD
273 if (error)
274 panic("Cannot get vnode for swapdev");
275 swapdev_vp->v_type = VNON; /* Untyped */
5fd012e0 276 vx_unlock(swapdev_vp);
984263bc
MD
277 }
278
984263bc 279 for (sp = swdevt, index = 0 ; index < nswdev; index++, sp++) {
99ad9bc4 280 if (sp->sw_vp == vp) {
138b6cd2
MD
281 error = EBUSY;
282 goto done;
99ad9bc4 283 }
984263bc
MD
284 if (!sp->sw_vp)
285 goto found;
286
287 }
138b6cd2
MD
288 error = EINVAL;
289 goto done;
984263bc 290 found:
ca466bae 291 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
87de5057 292 error = VOP_OPEN(vp, FREAD | FWRITE, cred, NULL);
a11aaa81 293 vn_unlock(vp);
138b6cd2
MD
294 if (error)
295 goto done;
984263bc 296
e4c9c0c8
MD
297 /*
298 * v_rdev is not valid until after the VOP_OPEN() call. dev_psize()
299 * must be supported if a character device has been specified.
300 */
301 if (vp->v_type == VCHR)
302 dev = vp->v_rdev;
303 else
028066b1 304 dev = NULL;
e4c9c0c8 305
e0fc5693
MD
306 if (nblks == 0 && dev != NULL) {
307 dpsize = dev_dpsize(dev);
308 if (dpsize == -1) {
309 VOP_CLOSE(vp, FREAD | FWRITE);
138b6cd2
MD
310 error = ENXIO;
311 goto done;
e0fc5693 312 }
79634a66 313 nblks = (u_quad_t)dpsize;
984263bc
MD
314 }
315 if (nblks == 0) {
87de5057 316 VOP_CLOSE(vp, FREAD | FWRITE);
138b6cd2
MD
317 error = ENXIO;
318 goto done;
984263bc
MD
319 }
320
321 /*
984263bc
MD
322 * nblks is in DEV_BSIZE'd chunks, convert to PAGE_SIZE'd chunks.
323 * First chop nblks off to page-align it, then convert.
324 *
325 * sw->sw_nblks is in page-sized chunks now too.
326 */
79634a66 327 nblks &= ~(u_quad_t)(ctodb(1) - 1);
984263bc
MD
328 nblks = dbtoc(nblks);
329
79634a66
MD
330 /*
331 * Post-conversion nblks must not be >= BLIST_MAXBLKS, and
332 * we impose a 4-swap-device limit so we have to divide it out
333 * further. Going beyond this will result in overflows in the
334 * blist code.
335 *
336 * Post-conversion nblks must fit within a (swblk_t), which
337 * this test also ensures.
338 */
339 if (nblks > BLIST_MAXBLKS / nswdev) {
340 kprintf("exceeded maximum of %d blocks per swap unit\n",
341 (int)BLIST_MAXBLKS / nswdev);
342 VOP_CLOSE(vp, FREAD | FWRITE);
138b6cd2
MD
343 error = ENXIO;
344 goto done;
79634a66
MD
345 }
346
984263bc
MD
347 sp->sw_vp = vp;
348 sp->sw_dev = dev2udev(dev);
349 sp->sw_device = dev;
9f3543c6 350 sp->sw_flags = SW_FREED;
099f3e5e 351 sp->sw_nused = 0;
984263bc
MD
352
353 /*
354 * nblks, nswap, and dmmax are PAGE_SIZE'd parameters now, not
355 * DEV_BSIZE'd. aligned_nblks is used to calculate the
356 * size of the swap bitmap, taking into account the stripe size.
357 */
79634a66 358 aligned_nblks = (swblk_t)((nblks + (dmmax - 1)) & ~(u_long)(dmmax - 1));
099f3e5e 359 sp->sw_nblks = aligned_nblks;
984263bc
MD
360
361 if (aligned_nblks * nswdev > nswap)
362 nswap = aligned_nblks * nswdev;
363
364 if (swapblist == NULL)
365 swapblist = blist_create(nswap);
366 else
367 blist_resize(&swapblist, nswap, 0);
368
099f3e5e
MD
369 for (dvbase = dmmax; dvbase < aligned_nblks; dvbase += dmmax) {
370 blk = min(aligned_nblks - dvbase, dmmax);
984263bc
MD
371 vsbase = index * dmmax + dvbase * nswdev;
372 blist_free(swapblist, vsbase, blk);
373 vm_swap_size += blk;
1e5196f0 374 vm_swap_max += blk;
984263bc 375 }
c84c24da 376 swap_pager_newswap();
138b6cd2
MD
377 error = 0;
378done:
99ad9bc4 379 mtx_unlock(&swap_mtx);
138b6cd2
MD
380 lwkt_reltoken(&vm_token);
381 return (error);
984263bc 382}
099f3e5e
MD
383
384/*
9f3543c6
MD
385 * swapoff_args(char *name)
386 *
387 * System call swapoff(name) disables swapping on device name,
388 * which must be an active swap device. Return ENOMEM
389 * if there is not enough memory to page in the contents of
390 * the given device.
391 *
392 * No requirements.
393 */
394int
395sys_swapoff(struct swapoff_args *uap)
396{
397 struct vnode *vp;
398 struct nlookupdata nd;
399 struct swdevt *sp;
400 int error, index;
401
402 error = priv_check(curthread, PRIV_ROOT);
403 if (error)
404 return (error);
405
406 mtx_lock(&swap_mtx);
407 get_mplock();
408 vp = NULL;
409 error = nlookup_init(&nd, uap->name, UIO_USERSPACE, NLC_FOLLOW);
410 if (error == 0)
411 error = nlookup(&nd);
412 if (error == 0)
413 error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp);
414 nlookup_done(&nd);
415 if (error)
416 goto done;
417
418 for (sp = swdevt, index = 0; index < nswdev; index++, sp++) {
419 if (sp->sw_vp == vp)
420 goto found;
421 }
422 error = EINVAL;
423 goto done;
424found:
425 error = swapoff_one(index);
426
427done:
428 rel_mplock();
429 mtx_unlock(&swap_mtx);
430 return (error);
431}
432
433static int
434swapoff_one(int index)
435{
436 swblk_t blk, aligned_nblks;
437 swblk_t dvbase, vsbase;
438 u_int pq_active_clean, pq_inactive_clean;
439 struct swdevt *sp;
b12defdc 440 struct vm_page marker;
9f3543c6 441 vm_page_t m;
027193eb 442 int q;
9f3543c6
MD
443
444 mtx_lock(&swap_mtx);
445
446 sp = &swdevt[index];
447 aligned_nblks = sp->sw_nblks;
448 pq_active_clean = pq_inactive_clean = 0;
449
450 /*
451 * We can turn off this swap device safely only if the
452 * available virtual memory in the system will fit the amount
453 * of data we will have to page back in, plus an epsilon so
454 * the system doesn't become critically low on swap space.
455 */
51c99c61 456 for (q = 0; q < PQ_L2_SIZE; ++q) {
027193eb
MD
457 bzero(&marker, sizeof(marker));
458 marker.flags = PG_BUSY | PG_FICTITIOUS | PG_MARKER;
459 marker.queue = PQ_ACTIVE + q;
460 marker.pc = q;
461 marker.wire_count = 1;
462
463 vm_page_queues_spin_lock(marker.queue);
464 TAILQ_INSERT_HEAD(&vm_page_queues[marker.queue].pl,
465 &marker, pageq);
466
467 while ((m = TAILQ_NEXT(&marker, pageq)) != NULL) {
468 TAILQ_REMOVE(&vm_page_queues[marker.queue].pl,
469 &marker, pageq);
470 TAILQ_INSERT_AFTER(&vm_page_queues[marker.queue].pl, m,
471 &marker, pageq);
472 if (m->flags & (PG_MARKER | PG_FICTITIOUS))
473 continue;
474
475 if (vm_page_busy_try(m, FALSE) == 0) {
476 vm_page_queues_spin_unlock(marker.queue);
477 if (m->dirty == 0) {
478 vm_page_test_dirty(m);
479 if (m->dirty == 0)
480 ++pq_active_clean;
481 }
482 vm_page_wakeup(m);
483 vm_page_queues_spin_lock(marker.queue);
b12defdc 484 }
9f3543c6 485 }
027193eb
MD
486 TAILQ_REMOVE(&vm_page_queues[marker.queue].pl, &marker, pageq);
487 vm_page_queues_spin_unlock(marker.queue);
488
489 marker.queue = PQ_INACTIVE + q;
490 marker.pc = q;
491 vm_page_queues_spin_lock(marker.queue);
492 TAILQ_INSERT_HEAD(&vm_page_queues[marker.queue].pl,
493 &marker, pageq);
494
495 while ((m = TAILQ_NEXT(&marker, pageq)) != NULL) {
496 TAILQ_REMOVE(
497 &vm_page_queues[marker.queue].pl,
498 &marker, pageq);
499 TAILQ_INSERT_AFTER(
500 &vm_page_queues[marker.queue].pl,
501 m, &marker, pageq);
502 if (m->flags & (PG_MARKER | PG_FICTITIOUS))
503 continue;
504
505 if (vm_page_busy_try(m, FALSE) == 0) {
506 vm_page_queues_spin_unlock(marker.queue);
507 if (m->dirty == 0) {
508 vm_page_test_dirty(m);
509 if (m->dirty == 0)
510 ++pq_inactive_clean;
511 }
512 vm_page_wakeup(m);
513 vm_page_queues_spin_lock(marker.queue);
b12defdc 514 }
9f3543c6 515 }
027193eb
MD
516 TAILQ_REMOVE(&vm_page_queues[marker.queue].pl,
517 &marker, pageq);
518 vm_page_queues_spin_unlock(marker.queue);
9f3543c6 519 }
9f3543c6
MD
520
521 if (vmstats.v_free_count + vmstats.v_cache_count + pq_active_clean +
522 pq_inactive_clean + vm_swap_size < aligned_nblks + nswap_lowat) {
523 mtx_unlock(&swap_mtx);
524 return (ENOMEM);
525 }
526
527 /*
528 * Prevent further allocations on this device
529 */
530 sp->sw_flags |= SW_CLOSING;
531 for (dvbase = dmmax; dvbase < aligned_nblks; dvbase += dmmax) {
532 blk = min(aligned_nblks - dvbase, dmmax);
533 vsbase = index * dmmax + dvbase * nswdev;
534 vm_swap_size -= blist_fill(swapblist, vsbase, blk);
535 vm_swap_max -= blk;
536 }
537
538 /*
539 * Page in the contents of the device and close it.
540 */
541 if (swap_pager_swapoff(index)) {
542 mtx_unlock(&swap_mtx);
543 return (EINTR);
544 }
545
546 VOP_CLOSE(sp->sw_vp, FREAD | FWRITE);
547 vrele(sp->sw_vp);
548 bzero(swdevt + index, sizeof(struct swdevt));
549
550 /*
551 * Resize the bitmap based on the nem largest swap device,
552 * or free the bitmap if there are no more devices.
553 */
554 for (sp = swdevt, aligned_nblks = 0; sp < swdevt + nswdev; sp++) {
555 if (sp->sw_vp)
556 aligned_nblks = max(aligned_nblks, sp->sw_nblks);
557 }
558
559 nswap = aligned_nblks * nswdev;
560
561 if (nswap == 0) {
562 blist_destroy(swapblist);
563 swapblist = NULL;
564 vrele(swapdev_vp);
565 swapdev_vp = NULL;
566 } else {
567 blist_resize(&swapblist, nswap, 0);
568 }
569
570 mtx_unlock(&swap_mtx);
571 return (0);
572}
573
574/*
099f3e5e
MD
575 * Account for swap space in individual swdevt's. The caller ensures
576 * that the provided range falls into a single swdevt.
577 *
578 * +count space freed
579 * -count space allocated
580 */
581void
582swapacctspace(swblk_t base, swblk_t count)
583{
584 int index;
585 int seg;
586
587 vm_swap_size += count;
588 seg = base / dmmax;
589 index = seg % nswdev;
590 swdevt[index].sw_nused -= count;
591}
592
593/*
594 * Retrieve swap info
595 */
596static int
597sysctl_vm_swap_info(SYSCTL_HANDLER_ARGS)
598{
599 struct xswdev xs;
600 struct swdevt *sp;
601 int error;
602 int n;
603
604 error = 0;
605 for (n = 0; n < nswdev; ++n) {
606 sp = &swdevt[n];
607
608 xs.xsw_size = sizeof(xs);
609 xs.xsw_version = XSWDEV_VERSION;
610 xs.xsw_blksize = PAGE_SIZE;
611 xs.xsw_dev = sp->sw_dev;
612 xs.xsw_flags = sp->sw_flags;
613 xs.xsw_nblks = sp->sw_nblks;
614 xs.xsw_used = sp->sw_nused;
615
616 error = SYSCTL_OUT(req, &xs, sizeof(xs));
617 if (error)
618 break;
619 }
620 return (error);
621}
622
623SYSCTL_INT(_vm, OID_AUTO, nswapdev, CTLFLAG_RD, &nswdev, 0,
624 "Number of swap devices");
625SYSCTL_NODE(_vm, OID_AUTO, swap_info_array, CTLFLAG_RD, sysctl_vm_swap_info,
626 "Swap statistics by device");