4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; If not, see
18 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
20 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21 * CA 95054 USA or visit www.sun.com if you need additional information or
27 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
30 * Copyright (c) 2011, 2015, Intel Corporation.
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
36 * Implementation of cl_page for OSC layer.
38 * Author: Nikita Danilov <nikita.danilov@sun.com>
41 #define DEBUG_SUBSYSTEM S_OSC
43 #include "osc_cl_internal.h"
45 static void osc_lru_del(struct client_obd
*cli
, struct osc_page
*opg
, bool del
);
46 static void osc_lru_add(struct client_obd
*cli
, struct osc_page
*opg
);
47 static int osc_lru_reserve(const struct lu_env
*env
, struct osc_object
*obj
,
48 struct osc_page
*opg
);
54 static int osc_page_protected(const struct lu_env
*env
,
55 const struct osc_page
*opg
,
56 enum cl_lock_mode mode
, int unref
)
61 /*****************************************************************************
66 static void osc_page_fini(const struct lu_env
*env
,
67 struct cl_page_slice
*slice
)
69 struct osc_page
*opg
= cl2osc_page(slice
);
71 CDEBUG(D_TRACE
, "%p\n", opg
);
72 LASSERT(!opg
->ops_lock
);
75 static void osc_page_transfer_get(struct osc_page
*opg
, const char *label
)
77 struct cl_page
*page
= cl_page_top(opg
->ops_cl
.cpl_page
);
79 LASSERT(!opg
->ops_transfer_pinned
);
81 lu_ref_add_atomic(&page
->cp_reference
, label
, page
);
82 opg
->ops_transfer_pinned
= 1;
85 static void osc_page_transfer_put(const struct lu_env
*env
,
88 struct cl_page
*page
= cl_page_top(opg
->ops_cl
.cpl_page
);
90 if (opg
->ops_transfer_pinned
) {
91 lu_ref_del(&page
->cp_reference
, "transfer", page
);
92 opg
->ops_transfer_pinned
= 0;
93 cl_page_put(env
, page
);
98 * This is called once for every page when it is submitted for a transfer
99 * either opportunistic (osc_page_cache_add()), or immediate
100 * (osc_page_submit()).
102 static void osc_page_transfer_add(const struct lu_env
*env
,
103 struct osc_page
*opg
, enum cl_req_type crt
)
105 struct osc_object
*obj
= cl2osc(opg
->ops_cl
.cpl_obj
);
107 /* ops_lru and ops_inflight share the same field, so take it from LRU
108 * first and then use it as inflight.
110 osc_lru_del(osc_cli(obj
), opg
, false);
112 spin_lock(&obj
->oo_seatbelt
);
113 list_add(&opg
->ops_inflight
, &obj
->oo_inflight
[crt
]);
114 opg
->ops_submitter
= current
;
115 spin_unlock(&obj
->oo_seatbelt
);
118 static int osc_page_cache_add(const struct lu_env
*env
,
119 const struct cl_page_slice
*slice
,
122 struct osc_io
*oio
= osc_env_io(env
);
123 struct osc_page
*opg
= cl2osc_page(slice
);
126 LINVRNT(osc_page_protected(env
, opg
, CLM_WRITE
, 0));
128 osc_page_transfer_get(opg
, "transfer\0cache");
129 result
= osc_queue_async_io(env
, io
, opg
);
131 osc_page_transfer_put(env
, opg
);
133 osc_page_transfer_add(env
, opg
, CRT_WRITE
);
135 /* for sync write, kernel will wait for this page to be flushed before
136 * osc_io_end() is called, so release it earlier.
137 * for mkwrite(), it's known there is no further pages.
139 if (cl_io_is_sync_write(io
) || cl_io_is_mkwrite(io
)) {
140 if (oio
->oi_active
) {
141 osc_extent_release(env
, oio
->oi_active
);
142 oio
->oi_active
= NULL
;
149 void osc_index2policy(ldlm_policy_data_t
*policy
, const struct cl_object
*obj
,
150 pgoff_t start
, pgoff_t end
)
152 memset(policy
, 0, sizeof(*policy
));
153 policy
->l_extent
.start
= cl_offset(obj
, start
);
154 policy
->l_extent
.end
= cl_offset(obj
, end
+ 1) - 1;
157 static int osc_page_addref_lock(const struct lu_env
*env
,
158 struct osc_page
*opg
,
159 struct cl_lock
*lock
)
161 struct osc_lock
*olock
;
164 LASSERT(!opg
->ops_lock
);
166 olock
= osc_lock_at(lock
);
167 if (atomic_inc_return(&olock
->ols_pageref
) <= 0) {
168 atomic_dec(&olock
->ols_pageref
);
172 opg
->ops_lock
= lock
;
178 static void osc_page_putref_lock(const struct lu_env
*env
,
179 struct osc_page
*opg
)
181 struct cl_lock
*lock
= opg
->ops_lock
;
182 struct osc_lock
*olock
;
185 olock
= osc_lock_at(lock
);
187 atomic_dec(&olock
->ols_pageref
);
188 opg
->ops_lock
= NULL
;
190 cl_lock_put(env
, lock
);
193 static int osc_page_is_under_lock(const struct lu_env
*env
,
194 const struct cl_page_slice
*slice
,
195 struct cl_io
*unused
)
197 struct cl_lock
*lock
;
198 int result
= -ENODATA
;
200 lock
= cl_lock_at_page(env
, slice
->cpl_obj
, slice
->cpl_page
,
203 if (osc_page_addref_lock(env
, cl2osc_page(slice
), lock
) == 0)
205 cl_lock_put(env
, lock
);
210 static void osc_page_disown(const struct lu_env
*env
,
211 const struct cl_page_slice
*slice
,
214 struct osc_page
*opg
= cl2osc_page(slice
);
216 if (unlikely(opg
->ops_lock
))
217 osc_page_putref_lock(env
, opg
);
220 static void osc_page_completion_read(const struct lu_env
*env
,
221 const struct cl_page_slice
*slice
,
224 struct osc_page
*opg
= cl2osc_page(slice
);
225 struct osc_object
*obj
= cl2osc(opg
->ops_cl
.cpl_obj
);
227 if (likely(opg
->ops_lock
))
228 osc_page_putref_lock(env
, opg
);
229 osc_lru_add(osc_cli(obj
), opg
);
232 static void osc_page_completion_write(const struct lu_env
*env
,
233 const struct cl_page_slice
*slice
,
236 struct osc_page
*opg
= cl2osc_page(slice
);
237 struct osc_object
*obj
= cl2osc(slice
->cpl_obj
);
239 osc_lru_add(osc_cli(obj
), opg
);
242 static int osc_page_fail(const struct lu_env
*env
,
243 const struct cl_page_slice
*slice
,
244 struct cl_io
*unused
)
253 static const char *osc_list(struct list_head
*head
)
255 return list_empty(head
) ? "-" : "+";
258 static inline unsigned long osc_submit_duration(struct osc_page
*opg
)
260 if (opg
->ops_submit_time
== 0)
263 return (cfs_time_current() - opg
->ops_submit_time
);
266 static int osc_page_print(const struct lu_env
*env
,
267 const struct cl_page_slice
*slice
,
268 void *cookie
, lu_printer_t printer
)
270 struct osc_page
*opg
= cl2osc_page(slice
);
271 struct osc_async_page
*oap
= &opg
->ops_oap
;
272 struct osc_object
*obj
= cl2osc(slice
->cpl_obj
);
273 struct client_obd
*cli
= &osc_export(obj
)->exp_obd
->u
.cli
;
275 return (*printer
)(env
, cookie
, LUSTRE_OSC_NAME
"-page@%p: 1< %#x %d %u %s %s > 2< %llu %u %u %#x %#x | %p %p %p > 3< %s %p %d %lu %d > 4< %d %d %d %lu %s | %s %s %s %s > 5< %s %s %s %s | %d %s | %d %s %s>\n",
278 oap
->oap_magic
, oap
->oap_cmd
,
279 oap
->oap_interrupted
,
280 osc_list(&oap
->oap_pending_item
),
281 osc_list(&oap
->oap_rpc_item
),
283 oap
->oap_obj_off
, oap
->oap_page_off
, oap
->oap_count
,
284 oap
->oap_async_flags
, oap
->oap_brw_flags
,
285 oap
->oap_request
, oap
->oap_cli
, obj
,
287 osc_list(&opg
->ops_inflight
),
288 opg
->ops_submitter
, opg
->ops_transfer_pinned
,
289 osc_submit_duration(opg
), opg
->ops_srvlock
,
291 cli
->cl_r_in_flight
, cli
->cl_w_in_flight
,
292 cli
->cl_max_rpcs_in_flight
,
294 osc_list(&cli
->cl_cache_waiters
),
295 osc_list(&cli
->cl_loi_ready_list
),
296 osc_list(&cli
->cl_loi_hp_ready_list
),
297 osc_list(&cli
->cl_loi_write_list
),
298 osc_list(&cli
->cl_loi_read_list
),
300 osc_list(&obj
->oo_ready_item
),
301 osc_list(&obj
->oo_hp_ready_item
),
302 osc_list(&obj
->oo_write_item
),
303 osc_list(&obj
->oo_read_item
),
304 atomic_read(&obj
->oo_nr_reads
),
305 osc_list(&obj
->oo_reading_exts
),
306 atomic_read(&obj
->oo_nr_writes
),
307 osc_list(&obj
->oo_hp_exts
),
308 osc_list(&obj
->oo_urgent_exts
));
311 static void osc_page_delete(const struct lu_env
*env
,
312 const struct cl_page_slice
*slice
)
314 struct osc_page
*opg
= cl2osc_page(slice
);
315 struct osc_object
*obj
= cl2osc(opg
->ops_cl
.cpl_obj
);
318 LINVRNT(opg
->ops_temp
|| osc_page_protected(env
, opg
, CLM_READ
, 1));
320 CDEBUG(D_TRACE
, "%p\n", opg
);
321 osc_page_transfer_put(env
, opg
);
322 rc
= osc_teardown_async_page(env
, obj
, opg
);
324 CL_PAGE_DEBUG(D_ERROR
, env
, cl_page_top(slice
->cpl_page
),
325 "Trying to teardown failed: %d\n", rc
);
329 spin_lock(&obj
->oo_seatbelt
);
330 if (opg
->ops_submitter
) {
331 LASSERT(!list_empty(&opg
->ops_inflight
));
332 list_del_init(&opg
->ops_inflight
);
333 opg
->ops_submitter
= NULL
;
335 spin_unlock(&obj
->oo_seatbelt
);
337 osc_lru_del(osc_cli(obj
), opg
, true);
340 static void osc_page_clip(const struct lu_env
*env
,
341 const struct cl_page_slice
*slice
, int from
, int to
)
343 struct osc_page
*opg
= cl2osc_page(slice
);
344 struct osc_async_page
*oap
= &opg
->ops_oap
;
346 LINVRNT(osc_page_protected(env
, opg
, CLM_READ
, 0));
348 opg
->ops_from
= from
;
350 spin_lock(&oap
->oap_lock
);
351 oap
->oap_async_flags
|= ASYNC_COUNT_STABLE
;
352 spin_unlock(&oap
->oap_lock
);
355 static int osc_page_cancel(const struct lu_env
*env
,
356 const struct cl_page_slice
*slice
)
358 struct osc_page
*opg
= cl2osc_page(slice
);
361 LINVRNT(osc_page_protected(env
, opg
, CLM_READ
, 0));
363 /* Check if the transferring against this page
364 * is completed, or not even queued.
366 if (opg
->ops_transfer_pinned
)
367 /* FIXME: may not be interrupted.. */
368 rc
= osc_cancel_async_page(env
, opg
);
369 LASSERT(ergo(rc
== 0, opg
->ops_transfer_pinned
== 0));
373 static int osc_page_flush(const struct lu_env
*env
,
374 const struct cl_page_slice
*slice
,
377 struct osc_page
*opg
= cl2osc_page(slice
);
380 rc
= osc_flush_async_page(env
, io
, opg
);
384 static const struct cl_page_operations osc_page_ops
= {
385 .cpo_fini
= osc_page_fini
,
386 .cpo_print
= osc_page_print
,
387 .cpo_delete
= osc_page_delete
,
388 .cpo_is_under_lock
= osc_page_is_under_lock
,
389 .cpo_disown
= osc_page_disown
,
392 .cpo_cache_add
= osc_page_fail
,
393 .cpo_completion
= osc_page_completion_read
396 .cpo_cache_add
= osc_page_cache_add
,
397 .cpo_completion
= osc_page_completion_write
400 .cpo_clip
= osc_page_clip
,
401 .cpo_cancel
= osc_page_cancel
,
402 .cpo_flush
= osc_page_flush
405 int osc_page_init(const struct lu_env
*env
, struct cl_object
*obj
,
406 struct cl_page
*page
, struct page
*vmpage
)
408 struct osc_object
*osc
= cl2osc(obj
);
409 struct osc_page
*opg
= cl_object_page_slice(obj
, page
);
413 opg
->ops_to
= PAGE_SIZE
;
415 result
= osc_prep_async_page(osc
, opg
, vmpage
,
416 cl_offset(obj
, page
->cp_index
));
418 struct osc_io
*oio
= osc_env_io(env
);
420 opg
->ops_srvlock
= osc_io_srvlock(oio
);
421 cl_page_slice_add(page
, &opg
->ops_cl
, obj
, &osc_page_ops
);
424 * Cannot assert osc_page_protected() here as read-ahead
425 * creates temporary pages outside of a lock.
427 /* ops_inflight and ops_lru are the same field, but it doesn't
428 * hurt to initialize it twice :-)
430 INIT_LIST_HEAD(&opg
->ops_inflight
);
431 INIT_LIST_HEAD(&opg
->ops_lru
);
433 /* reserve an LRU space for this page */
434 if (page
->cp_type
== CPT_CACHEABLE
&& result
== 0)
435 result
= osc_lru_reserve(env
, osc
, opg
);
441 * Helper function called by osc_io_submit() for every page in an immediate
442 * transfer (i.e., transferred synchronously).
444 void osc_page_submit(const struct lu_env
*env
, struct osc_page
*opg
,
445 enum cl_req_type crt
, int brw_flags
)
447 struct osc_async_page
*oap
= &opg
->ops_oap
;
448 struct osc_object
*obj
= oap
->oap_obj
;
450 LINVRNT(osc_page_protected(env
, opg
,
451 crt
== CRT_WRITE
? CLM_WRITE
: CLM_READ
, 1));
453 LASSERTF(oap
->oap_magic
== OAP_MAGIC
, "Bad oap magic: oap %p, magic 0x%x\n",
454 oap
, oap
->oap_magic
);
455 LASSERT(oap
->oap_async_flags
& ASYNC_READY
);
456 LASSERT(oap
->oap_async_flags
& ASYNC_COUNT_STABLE
);
458 oap
->oap_cmd
= crt
== CRT_WRITE
? OBD_BRW_WRITE
: OBD_BRW_READ
;
459 oap
->oap_page_off
= opg
->ops_from
;
460 oap
->oap_count
= opg
->ops_to
- opg
->ops_from
;
461 oap
->oap_brw_flags
= brw_flags
| OBD_BRW_SYNC
;
463 if (!client_is_remote(osc_export(obj
)) &&
464 capable(CFS_CAP_SYS_RESOURCE
)) {
465 oap
->oap_brw_flags
|= OBD_BRW_NOQUOTA
;
466 oap
->oap_cmd
|= OBD_BRW_NOQUOTA
;
469 opg
->ops_submit_time
= cfs_time_current();
470 osc_page_transfer_get(opg
, "transfer\0imm");
471 osc_page_transfer_add(env
, opg
, crt
);
474 /* --------------- LRU page management ------------------ */
476 /* OSC is a natural place to manage LRU pages as applications are specialized
477 * to write OSC by OSC. Ideally, if one OSC is used more frequently it should
478 * occupy more LRU slots. On the other hand, we should avoid using up all LRU
479 * slots (client_obd::cl_lru_left) otherwise process has to be put into sleep
480 * for free LRU slots - this will be very bad so the algorithm requires each
481 * OSC to free slots voluntarily to maintain a reasonable number of free slots
485 static DECLARE_WAIT_QUEUE_HEAD(osc_lru_waitq
);
486 static atomic_t osc_lru_waiters
= ATOMIC_INIT(0);
487 /* LRU pages are freed in batch mode. OSC should at least free this
488 * number of pages to avoid running out of LRU budget, and..
490 static const int lru_shrink_min
= 2 << (20 - PAGE_SHIFT
); /* 2M */
491 /* free this number at most otherwise it will take too long time to finish. */
492 static const int lru_shrink_max
= 32 << (20 - PAGE_SHIFT
); /* 32M */
494 /* Check if we can free LRU slots from this OSC. If there exists LRU waiters,
495 * we should free slots aggressively. In this way, slots are freed in a steady
496 * step to maintain fairness among OSCs.
498 * Return how many LRU pages should be freed.
500 static int osc_cache_too_much(struct client_obd
*cli
)
502 struct cl_client_cache
*cache
= cli
->cl_cache
;
503 int pages
= atomic_read(&cli
->cl_lru_in_list
) >> 1;
505 if (atomic_read(&osc_lru_waiters
) > 0 &&
506 atomic_read(cli
->cl_lru_left
) < lru_shrink_max
)
507 /* drop lru pages aggressively */
508 return min(pages
, lru_shrink_max
);
510 /* if it's going to run out LRU slots, we should free some, but not
511 * too much to maintain fairness among OSCs.
513 if (atomic_read(cli
->cl_lru_left
) < cache
->ccc_lru_max
>> 4) {
516 tmp
= cache
->ccc_lru_max
/ atomic_read(&cache
->ccc_users
);
518 return min(pages
, lru_shrink_max
);
520 return pages
> lru_shrink_min
? lru_shrink_min
: 0;
526 /* Return how many pages are not discarded in @pvec. */
527 static int discard_pagevec(const struct lu_env
*env
, struct cl_io
*io
,
528 struct cl_page
**pvec
, int max_index
)
533 for (count
= 0, i
= 0; i
< max_index
; i
++) {
534 struct cl_page
*page
= pvec
[i
];
536 if (cl_page_own_try(env
, io
, page
) == 0) {
537 /* free LRU page only if nobody is using it.
538 * This check is necessary to avoid freeing the pages
539 * having already been removed from LRU and pinned
542 if (!cl_page_in_use(page
)) {
543 cl_page_unmap(env
, io
, page
);
544 cl_page_discard(env
, io
, page
);
547 cl_page_disown(env
, io
, page
);
549 cl_page_put(env
, page
);
552 return max_index
- count
;
556 * Drop @target of pages from LRU at most.
558 int osc_lru_shrink(struct client_obd
*cli
, int target
)
560 struct cl_env_nest nest
;
563 struct cl_object
*clobj
= NULL
;
564 struct cl_page
**pvec
;
565 struct osc_page
*opg
;
566 struct osc_page
*temp
;
572 LASSERT(atomic_read(&cli
->cl_lru_in_list
) >= 0);
573 if (atomic_read(&cli
->cl_lru_in_list
) == 0 || target
<= 0)
576 env
= cl_env_nested_get(&nest
);
580 pvec
= osc_env_info(env
)->oti_pvec
;
581 io
= &osc_env_info(env
)->oti_io
;
583 client_obd_list_lock(&cli
->cl_lru_list_lock
);
584 atomic_inc(&cli
->cl_lru_shrinkers
);
585 maxscan
= min(target
<< 1, atomic_read(&cli
->cl_lru_in_list
));
586 list_for_each_entry_safe(opg
, temp
, &cli
->cl_lru_list
, ops_lru
) {
587 struct cl_page
*page
;
592 page
= cl_page_top(opg
->ops_cl
.cpl_page
);
593 if (cl_page_in_use_noref(page
)) {
594 list_move_tail(&opg
->ops_lru
, &cli
->cl_lru_list
);
598 LASSERT(page
->cp_obj
);
599 if (clobj
!= page
->cp_obj
) {
600 struct cl_object
*tmp
= page
->cp_obj
;
603 client_obd_list_unlock(&cli
->cl_lru_list_lock
);
606 count
-= discard_pagevec(env
, io
, pvec
, index
);
610 cl_object_put(env
, clobj
);
616 io
->ci_ignore_layout
= 1;
617 rc
= cl_io_init(env
, io
, CIT_MISC
, clobj
);
619 client_obd_list_lock(&cli
->cl_lru_list_lock
);
628 /* move this page to the end of list as it will be discarded
629 * soon. The page will be finally removed from LRU list in
632 list_move_tail(&opg
->ops_lru
, &cli
->cl_lru_list
);
634 /* it's okay to grab a refcount here w/o holding lock because
635 * it has to grab cl_lru_list_lock to delete the page.
638 pvec
[index
++] = page
;
639 if (++count
>= target
)
642 if (unlikely(index
== OTI_PVEC_SIZE
)) {
643 client_obd_list_unlock(&cli
->cl_lru_list_lock
);
644 count
-= discard_pagevec(env
, io
, pvec
, index
);
647 client_obd_list_lock(&cli
->cl_lru_list_lock
);
650 client_obd_list_unlock(&cli
->cl_lru_list_lock
);
653 count
-= discard_pagevec(env
, io
, pvec
, index
);
656 cl_object_put(env
, clobj
);
658 cl_env_nested_put(&nest
, env
);
660 atomic_dec(&cli
->cl_lru_shrinkers
);
661 return count
> 0 ? count
: rc
;
664 static void osc_lru_add(struct client_obd
*cli
, struct osc_page
*opg
)
668 if (!opg
->ops_in_lru
)
671 atomic_dec(&cli
->cl_lru_busy
);
672 client_obd_list_lock(&cli
->cl_lru_list_lock
);
673 if (list_empty(&opg
->ops_lru
)) {
674 list_move_tail(&opg
->ops_lru
, &cli
->cl_lru_list
);
675 atomic_inc_return(&cli
->cl_lru_in_list
);
676 wakeup
= atomic_read(&osc_lru_waiters
) > 0;
678 client_obd_list_unlock(&cli
->cl_lru_list_lock
);
681 osc_lru_shrink(cli
, osc_cache_too_much(cli
));
682 wake_up_all(&osc_lru_waitq
);
686 /* delete page from LRUlist. The page can be deleted from LRUlist for two
687 * reasons: redirtied or deleted from page cache.
689 static void osc_lru_del(struct client_obd
*cli
, struct osc_page
*opg
, bool del
)
691 if (opg
->ops_in_lru
) {
692 client_obd_list_lock(&cli
->cl_lru_list_lock
);
693 if (!list_empty(&opg
->ops_lru
)) {
694 LASSERT(atomic_read(&cli
->cl_lru_in_list
) > 0);
695 list_del_init(&opg
->ops_lru
);
696 atomic_dec(&cli
->cl_lru_in_list
);
698 atomic_inc(&cli
->cl_lru_busy
);
700 LASSERT(atomic_read(&cli
->cl_lru_busy
) > 0);
701 atomic_dec(&cli
->cl_lru_busy
);
703 client_obd_list_unlock(&cli
->cl_lru_list_lock
);
705 atomic_inc(cli
->cl_lru_left
);
706 /* this is a great place to release more LRU pages if
707 * this osc occupies too many LRU pages and kernel is
708 * stealing one of them.
709 * cl_lru_shrinkers is to avoid recursive call in case
710 * we're already in the context of osc_lru_shrink().
712 if (atomic_read(&cli
->cl_lru_shrinkers
) == 0 &&
713 !memory_pressure_get())
714 osc_lru_shrink(cli
, osc_cache_too_much(cli
));
715 wake_up(&osc_lru_waitq
);
718 LASSERT(list_empty(&opg
->ops_lru
));
722 static inline int max_to_shrink(struct client_obd
*cli
)
724 return min(atomic_read(&cli
->cl_lru_in_list
) >> 1, lru_shrink_max
);
727 static int osc_lru_reclaim(struct client_obd
*cli
)
729 struct cl_client_cache
*cache
= cli
->cl_cache
;
735 rc
= osc_lru_shrink(cli
, lru_shrink_min
);
737 CDEBUG(D_CACHE
, "%s: Free %d pages from own LRU: %p.\n",
738 cli
->cl_import
->imp_obd
->obd_name
, rc
, cli
);
742 CDEBUG(D_CACHE
, "%s: cli %p no free slots, pages: %d, busy: %d.\n",
743 cli
->cl_import
->imp_obd
->obd_name
, cli
,
744 atomic_read(&cli
->cl_lru_in_list
),
745 atomic_read(&cli
->cl_lru_busy
));
747 /* Reclaim LRU slots from other client_obd as it can't free enough
748 * from its own. This should rarely happen.
750 spin_lock(&cache
->ccc_lru_lock
);
751 LASSERT(!list_empty(&cache
->ccc_lru
));
753 cache
->ccc_lru_shrinkers
++;
754 list_move_tail(&cli
->cl_lru_osc
, &cache
->ccc_lru
);
756 max_scans
= atomic_read(&cache
->ccc_users
);
757 while (--max_scans
> 0 && !list_empty(&cache
->ccc_lru
)) {
758 cli
= list_entry(cache
->ccc_lru
.next
, struct client_obd
,
761 CDEBUG(D_CACHE
, "%s: cli %p LRU pages: %d, busy: %d.\n",
762 cli
->cl_import
->imp_obd
->obd_name
, cli
,
763 atomic_read(&cli
->cl_lru_in_list
),
764 atomic_read(&cli
->cl_lru_busy
));
766 list_move_tail(&cli
->cl_lru_osc
, &cache
->ccc_lru
);
767 if (atomic_read(&cli
->cl_lru_in_list
) > 0) {
768 spin_unlock(&cache
->ccc_lru_lock
);
770 rc
= osc_lru_shrink(cli
, max_to_shrink(cli
));
771 spin_lock(&cache
->ccc_lru_lock
);
776 spin_unlock(&cache
->ccc_lru_lock
);
778 CDEBUG(D_CACHE
, "%s: cli %p freed %d pages.\n",
779 cli
->cl_import
->imp_obd
->obd_name
, cli
, rc
);
783 static int osc_lru_reserve(const struct lu_env
*env
, struct osc_object
*obj
,
784 struct osc_page
*opg
)
786 struct l_wait_info lwi
= LWI_INTR(LWI_ON_SIGNAL_NOOP
, NULL
);
787 struct client_obd
*cli
= osc_cli(obj
);
790 if (!cli
->cl_cache
) /* shall not be in LRU */
793 LASSERT(atomic_read(cli
->cl_lru_left
) >= 0);
794 while (!atomic_add_unless(cli
->cl_lru_left
, -1, 0)) {
797 /* run out of LRU spaces, try to drop some by itself */
798 rc
= osc_lru_reclaim(cli
);
806 /* slowest case, all of caching pages are busy, notifying
807 * other OSCs that we're lack of LRU slots.
809 atomic_inc(&osc_lru_waiters
);
811 gen
= atomic_read(&cli
->cl_lru_in_list
);
812 rc
= l_wait_event(osc_lru_waitq
,
813 atomic_read(cli
->cl_lru_left
) > 0 ||
814 (atomic_read(&cli
->cl_lru_in_list
) > 0 &&
815 gen
!= atomic_read(&cli
->cl_lru_in_list
)),
818 atomic_dec(&osc_lru_waiters
);
824 atomic_inc(&cli
->cl_lru_busy
);