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27 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
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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_CACHE_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_CACHE_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_CACHE_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);