X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=blobdiff_plain;f=lustre%2Fosc%2Fosc_page.c;h=affd0d265e0beedeb403c60018d9b2d64428bf54;hp=5dd26406e33ff21983de6e830d9fa81db41367a1;hb=27815a0611a2e315a9a7696a20c2f257d48aeb7e;hpb=419016ac3e53e798453106ec04412a4843620916 diff --git a/lustre/osc/osc_page.c b/lustre/osc/osc_page.c index 5dd2640..affd0d2 100644 --- a/lustre/osc/osc_page.c +++ b/lustre/osc/osc_page.c @@ -1,6 +1,4 @@ -/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*- - * vim:expandtab:shiftwidth=8:tabstop=8: - * +/* * GPL HEADER START * * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. @@ -28,6 +26,8 @@ /* * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved. * Use is subject to license terms. + * + * Copyright (c) 2011, 2013, Intel Corporation. */ /* * This file is part of Lustre, http://www.lustre.org/ @@ -42,11 +42,16 @@ #include "osc_cl_internal.h" -/** \addtogroup osc - * @{ +static void osc_lru_del(struct client_obd *cli, struct osc_page *opg, bool del); +static void osc_lru_add(struct client_obd *cli, struct osc_page *opg); +static int osc_lru_reserve(const struct lu_env *env, struct osc_object *obj, + struct osc_page *opg); + +/** \addtogroup osc + * @{ */ -/* +/* * Comment out osc_page_protected because it may sleep inside the * the client_obd_list_lock. * client_obd_list_lock -> osc_ap_completion -> osc_completion -> @@ -58,23 +63,23 @@ static int osc_page_is_dlocked(const struct lu_env *env, const struct osc_page *opg, enum cl_lock_mode mode, int pending, int unref) { - struct cl_page *page; - struct osc_object *obj; - struct osc_thread_info *info; - struct ldlm_res_id *resname; - struct lustre_handle *lockh; - ldlm_policy_data_t *policy; - ldlm_mode_t dlmmode; - int flags; - - cfs_might_sleep(); - - info = osc_env_info(env); - resname = &info->oti_resname; - policy = &info->oti_policy; - lockh = &info->oti_handle; - page = opg->ops_cl.cpl_page; - obj = cl2osc(opg->ops_cl.cpl_obj); + struct cl_page *page; + struct osc_object *obj; + struct osc_thread_info *info; + struct ldlm_res_id *resname; + struct lustre_handle *lockh; + ldlm_policy_data_t *policy; + ldlm_mode_t dlmmode; + __u64 flags; + + might_sleep(); + + info = osc_env_info(env); + resname = &info->oti_resname; + policy = &info->oti_policy; + lockh = &info->oti_handle; + page = opg->ops_cl.cpl_page; + obj = cl2osc(opg->ops_cl.cpl_obj); flags = LDLM_FL_TEST_LOCK | LDLM_FL_BLOCK_GRANTED; if (pending) @@ -121,7 +126,7 @@ static int osc_page_protected(const struct lu_env *env, descr->cld_mode = mode; descr->cld_start = page->cp_index; descr->cld_end = page->cp_index; - cfs_spin_lock(&hdr->coh_lock_guard); + spin_lock(&hdr->coh_lock_guard); cfs_list_for_each_entry(scan, &hdr->coh_locks, cll_linkage) { /* * Lock-less sub-lock has to be either in HELD state @@ -139,7 +144,7 @@ static int osc_page_protected(const struct lu_env *env, break; } } - cfs_spin_unlock(&hdr->coh_lock_guard); + spin_unlock(&hdr->coh_lock_guard); } return result; } @@ -163,7 +168,6 @@ static void osc_page_fini(const struct lu_env *env, struct osc_page *opg = cl2osc_page(slice); CDEBUG(D_TRACE, "%p\n", opg); LASSERT(opg->ops_lock == NULL); - OBD_SLAB_FREE_PTR(opg, osc_page_kmem); } static void osc_page_transfer_get(struct osc_page *opg, const char *label) @@ -196,49 +200,47 @@ static void osc_page_transfer_put(const struct lu_env *env, static void osc_page_transfer_add(const struct lu_env *env, struct osc_page *opg, enum cl_req_type crt) { - struct osc_object *obj; + struct osc_object *obj = cl2osc(opg->ops_cl.cpl_obj); - LINVRNT(cl_page_is_vmlocked(env, opg->ops_cl.cpl_page)); + /* ops_lru and ops_inflight share the same field, so take it from LRU + * first and then use it as inflight. */ + osc_lru_del(osc_cli(obj), opg, false); - obj = cl2osc(opg->ops_cl.cpl_obj); - cfs_spin_lock(&obj->oo_seatbelt); - cfs_list_add(&opg->ops_inflight, &obj->oo_inflight[crt]); - opg->ops_submitter = cfs_current(); - cfs_spin_unlock(&obj->oo_seatbelt); + spin_lock(&obj->oo_seatbelt); + cfs_list_add(&opg->ops_inflight, &obj->oo_inflight[crt]); + opg->ops_submitter = current; + spin_unlock(&obj->oo_seatbelt); } static int osc_page_cache_add(const struct lu_env *env, - const struct cl_page_slice *slice, - struct cl_io *unused) + const struct cl_page_slice *slice, + struct cl_io *io) { - struct osc_page *opg = cl2osc_page(slice); - struct osc_object *obj = cl2osc(opg->ops_cl.cpl_obj); - int result; - /* All cacheable IO is async-capable */ - int brw_flags = OBD_BRW_ASYNC; - int noquota = 0; - - LINVRNT(osc_page_protected(env, opg, CLM_WRITE, 0)); - ENTRY; - - /* Set the OBD_BRW_SRVLOCK before the page is queued. */ - brw_flags |= opg->ops_srvlock ? OBD_BRW_SRVLOCK : 0; - if (!client_is_remote(osc_export(obj)) && - cfs_capable(CFS_CAP_SYS_RESOURCE)) { - brw_flags |= OBD_BRW_NOQUOTA; - noquota = OBD_BRW_NOQUOTA; - } - - osc_page_transfer_get(opg, "transfer\0cache"); - result = osc_queue_async_io(env, osc_export(obj), NULL, obj->oo_oinfo, - &opg->ops_oap, OBD_BRW_WRITE | noquota, - opg->ops_from, opg->ops_to - opg->ops_from, - brw_flags, 0); - if (result != 0) - osc_page_transfer_put(env, opg); - else - osc_page_transfer_add(env, opg, CRT_WRITE); - RETURN(result); + struct osc_io *oio = osc_env_io(env); + struct osc_page *opg = cl2osc_page(slice); + int result; + ENTRY; + + LINVRNT(osc_page_protected(env, opg, CLM_WRITE, 0)); + + osc_page_transfer_get(opg, "transfer\0cache"); + result = osc_queue_async_io(env, io, opg); + if (result != 0) + osc_page_transfer_put(env, opg); + else + osc_page_transfer_add(env, opg, CRT_WRITE); + + /* for sync write, kernel will wait for this page to be flushed before + * osc_io_end() is called, so release it earlier. + * for mkwrite(), it's known there is no further pages. */ + if (cl_io_is_sync_write(io) || cl_io_is_mkwrite(io)) { + if (oio->oi_active != NULL) { + osc_extent_release(env, oio->oi_active); + oio->oi_active = NULL; + } + } + + RETURN(result); } void osc_index2policy(ldlm_policy_data_t *policy, const struct cl_object *obj, @@ -261,9 +263,9 @@ static int osc_page_addref_lock(const struct lu_env *env, olock = osc_lock_at(lock); if (cfs_atomic_inc_return(&olock->ols_pageref) <= 0) { cfs_atomic_dec(&olock->ols_pageref); - cl_lock_put(env, lock); - rc = 1; + rc = -ENODATA; } else { + cl_lock_get(lock); opg->ops_lock = lock; rc = 0; } @@ -282,12 +284,6 @@ static void osc_page_putref_lock(const struct lu_env *env, cfs_atomic_dec(&olock->ols_pageref); opg->ops_lock = NULL; - /* - * Note: usually this won't be the last reference of the lock, but if - * it is, then all the lock_put do is at most just freeing some memory, - * so it would be OK that caller is holding spinlocks. - */ - LASSERT(cfs_atomic_read(&lock->cll_ref) > 1 || olock->ols_hold == 0); cl_lock_put(env, lock); } @@ -296,16 +292,16 @@ static int osc_page_is_under_lock(const struct lu_env *env, struct cl_io *unused) { struct cl_lock *lock; - int result; + int result = -ENODATA; ENTRY; lock = cl_lock_at_page(env, slice->cpl_obj, slice->cpl_page, NULL, 1, 0); - if (lock != NULL && - osc_page_addref_lock(env, cl2osc_page(slice), lock) == 0) - result = -EBUSY; - else - result = -ENODATA; + if (lock != NULL) { + if (osc_page_addref_lock(env, cl2osc_page(slice), lock) == 0) + result = -EBUSY; + cl_lock_put(env, lock); + } RETURN(result); } @@ -323,10 +319,22 @@ static void osc_page_completion_read(const struct lu_env *env, const struct cl_page_slice *slice, int ioret) { - struct osc_page *opg = cl2osc_page(slice); + struct osc_page *opg = cl2osc_page(slice); + struct osc_object *obj = cl2osc(opg->ops_cl.cpl_obj); - if (likely(opg->ops_lock)) - osc_page_putref_lock(env, opg); + if (likely(opg->ops_lock)) + osc_page_putref_lock(env, opg); + osc_lru_add(osc_cli(obj), opg); +} + +static void osc_page_completion_write(const struct lu_env *env, + const struct cl_page_slice *slice, + int ioret) +{ + struct osc_page *opg = cl2osc_page(slice); + struct osc_object *obj = cl2osc(slice->cpl_obj); + + osc_lru_add(osc_cli(obj), opg); } static int osc_page_fail(const struct lu_env *env, @@ -362,27 +370,23 @@ static int osc_page_print(const struct lu_env *env, struct osc_async_page *oap = &opg->ops_oap; struct osc_object *obj = cl2osc(slice->cpl_obj); struct client_obd *cli = &osc_export(obj)->exp_obd->u.cli; - struct lov_oinfo *loi = obj->oo_oinfo; return (*printer)(env, cookie, LUSTRE_OSC_NAME"-page@%p: " - "1< %#x %d %u %s %s %s > " - "2< "LPU64" %u %u %#x %#x | %p %p %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 %s | %d %s %s>\n", + "1< %#x %d %u %s %s > " + "2< "LPU64" %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", opg, /* 1 */ oap->oap_magic, oap->oap_cmd, oap->oap_interrupted, osc_list(&oap->oap_pending_item), - osc_list(&oap->oap_urgent_item), osc_list(&oap->oap_rpc_item), /* 2 */ oap->oap_obj_off, oap->oap_page_off, oap->oap_count, oap->oap_async_flags, oap->oap_brw_flags, - oap->oap_request, - oap->oap_cli, oap->oap_loi, oap->oap_caller_ops, - oap->oap_caller_data, + oap->oap_request, oap->oap_cli, obj, /* 3 */ osc_list(&opg->ops_inflight), opg->ops_submitter, opg->ops_transfer_pinned, @@ -397,24 +401,22 @@ static int osc_page_print(const struct lu_env *env, osc_list(&cli->cl_loi_write_list), osc_list(&cli->cl_loi_read_list), /* 5 */ - osc_list(&loi->loi_ready_item), - osc_list(&loi->loi_hp_ready_item), - osc_list(&loi->loi_write_item), - osc_list(&loi->loi_read_item), - loi->loi_read_lop.lop_num_pending, - osc_list(&loi->loi_read_lop.lop_pending), - osc_list(&loi->loi_read_lop.lop_urgent), - loi->loi_write_lop.lop_num_pending, - osc_list(&loi->loi_write_lop.lop_pending), - osc_list(&loi->loi_write_lop.lop_urgent)); + osc_list(&obj->oo_ready_item), + osc_list(&obj->oo_hp_ready_item), + osc_list(&obj->oo_write_item), + osc_list(&obj->oo_read_item), + cfs_atomic_read(&obj->oo_nr_reads), + osc_list(&obj->oo_reading_exts), + cfs_atomic_read(&obj->oo_nr_writes), + osc_list(&obj->oo_hp_exts), + osc_list(&obj->oo_urgent_exts)); } static void osc_page_delete(const struct lu_env *env, const struct cl_page_slice *slice) { - struct osc_page *opg = cl2osc_page(slice); - struct osc_object *obj = cl2osc(opg->ops_cl.cpl_obj); - struct osc_async_page *oap = &opg->ops_oap; + struct osc_page *opg = cl2osc_page(slice); + struct osc_object *obj = cl2osc(opg->ops_cl.cpl_obj); int rc; LINVRNT(opg->ops_temp || osc_page_protected(env, opg, CLM_READ, 1)); @@ -422,16 +424,23 @@ static void osc_page_delete(const struct lu_env *env, ENTRY; CDEBUG(D_TRACE, "%p\n", opg); osc_page_transfer_put(env, opg); - rc = osc_teardown_async_page(osc_export(obj), NULL, obj->oo_oinfo, oap); + rc = osc_teardown_async_page(env, obj, opg); if (rc) { CL_PAGE_DEBUG(D_ERROR, env, cl_page_top(slice->cpl_page), "Trying to teardown failed: %d\n", rc); LASSERT(0); } - cfs_spin_lock(&obj->oo_seatbelt); - cfs_list_del_init(&opg->ops_inflight); - cfs_spin_unlock(&obj->oo_seatbelt); - EXIT; + + spin_lock(&obj->oo_seatbelt); + if (opg->ops_submitter != NULL) { + LASSERT(!cfs_list_empty(&opg->ops_inflight)); + cfs_list_del_init(&opg->ops_inflight); + opg->ops_submitter = NULL; + } + spin_unlock(&obj->oo_seatbelt); + + osc_lru_del(osc_cli(obj), opg, true); + EXIT; } void osc_page_clip(const struct lu_env *env, const struct cl_page_slice *slice, @@ -444,31 +453,39 @@ void osc_page_clip(const struct lu_env *env, const struct cl_page_slice *slice, opg->ops_from = from; opg->ops_to = to; - cfs_spin_lock(&oap->oap_lock); - oap->oap_async_flags |= ASYNC_COUNT_STABLE; - cfs_spin_unlock(&oap->oap_lock); + spin_lock(&oap->oap_lock); + oap->oap_async_flags |= ASYNC_COUNT_STABLE; + spin_unlock(&oap->oap_lock); } static int osc_page_cancel(const struct lu_env *env, const struct cl_page_slice *slice) { - struct osc_page *opg = cl2osc_page(slice); - struct osc_async_page *oap = &opg->ops_oap; + struct osc_page *opg = cl2osc_page(slice); int rc = 0; LINVRNT(osc_page_protected(env, opg, CLM_READ, 0)); - client_obd_list_lock(&oap->oap_cli->cl_loi_list_lock); /* Check if the transferring against this page * is completed, or not even queued. */ if (opg->ops_transfer_pinned) /* FIXME: may not be interrupted.. */ - rc = osc_oap_interrupted(env, oap); + rc = osc_cancel_async_page(env, opg); LASSERT(ergo(rc == 0, opg->ops_transfer_pinned == 0)); - client_obd_list_unlock(&oap->oap_cli->cl_loi_list_lock); return rc; } +static int osc_page_flush(const struct lu_env *env, + const struct cl_page_slice *slice, + struct cl_io *io) +{ + struct osc_page *opg = cl2osc_page(slice); + int rc = 0; + ENTRY; + rc = osc_flush_async_page(env, io, opg); + RETURN(rc); +} + static const struct cl_page_operations osc_page_ops = { .cpo_fini = osc_page_fini, .cpo_print = osc_page_print, @@ -481,224 +498,460 @@ static const struct cl_page_operations osc_page_ops = { .cpo_completion = osc_page_completion_read }, [CRT_WRITE] = { - .cpo_cache_add = osc_page_cache_add - } - }, - .cpo_clip = osc_page_clip, - .cpo_cancel = osc_page_cancel + .cpo_cache_add = osc_page_cache_add, + .cpo_completion = osc_page_completion_write + } + }, + .cpo_clip = osc_page_clip, + .cpo_cancel = osc_page_cancel, + .cpo_flush = osc_page_flush }; -static int osc_make_ready(const struct lu_env *env, void *data, int cmd) +int osc_page_init(const struct lu_env *env, struct cl_object *obj, + struct cl_page *page, struct page *vmpage) { - struct osc_page *opg = data; - struct cl_page *page = cl_page_top(opg->ops_cl.cpl_page); - int result; + struct osc_object *osc = cl2osc(obj); + struct osc_page *opg = cl_object_page_slice(obj, page); + int result; + + opg->ops_from = 0; + opg->ops_to = PAGE_CACHE_SIZE; + + result = osc_prep_async_page(osc, opg, vmpage, + cl_offset(obj, page->cp_index)); + if (result == 0) { + struct osc_io *oio = osc_env_io(env); + opg->ops_srvlock = osc_io_srvlock(oio); + cl_page_slice_add(page, &opg->ops_cl, obj, + &osc_page_ops); + } + /* + * Cannot assert osc_page_protected() here as read-ahead + * creates temporary pages outside of a lock. + */ +#ifdef CONFIG_LUSTRE_DEBUG_EXPENSIVE_CHECK + opg->ops_temp = !osc_page_protected(env, opg, CLM_READ, 1); +#endif + /* ops_inflight and ops_lru are the same field, but it doesn't + * hurt to initialize it twice :-) */ + CFS_INIT_LIST_HEAD(&opg->ops_inflight); + CFS_INIT_LIST_HEAD(&opg->ops_lru); - LASSERT(cmd == OBD_BRW_WRITE); /* no cached reads */ - LINVRNT(osc_page_protected(env, opg, CLM_WRITE, 1)); + /* reserve an LRU space for this page */ + if (page->cp_type == CPT_CACHEABLE && result == 0) + result = osc_lru_reserve(env, osc, opg); - ENTRY; - result = cl_page_make_ready(env, page, CRT_WRITE); - if (result == 0) - opg->ops_submit_time = cfs_time_current(); - RETURN(result); + return result; } -static int osc_refresh_count(const struct lu_env *env, void *data, int cmd) +int osc_over_unstable_soft_limit(struct client_obd *cli) { - struct cl_page *page; - struct osc_page *osc = data; - struct cl_object *obj; - struct cl_attr *attr = &osc_env_info(env)->oti_attr; + long obd_upages, obd_dpages, osc_upages; + + /* Can't check cli->cl_unstable_count, therefore, no soft limit */ + if (cli == NULL) + return 0; + + obd_upages = cfs_atomic_read(&obd_unstable_pages); + obd_dpages = cfs_atomic_read(&obd_dirty_pages); + + osc_upages = cfs_atomic_read(&cli->cl_unstable_count); + + /* obd_max_dirty_pages is the max number of (dirty + unstable) + * pages allowed at any given time. To simulate an unstable page + * only limit, we subtract the current number of dirty pages + * from this max. This difference is roughly the amount of pages + * currently available for unstable pages. Thus, the soft limit + * is half of that difference. Check osc_upages to ensure we don't + * set SOFT_SYNC for OSCs without any outstanding unstable pages. */ + return osc_upages != 0 && + obd_upages >= (obd_max_dirty_pages - obd_dpages) / 2; +} - int result; - loff_t kms; - - LINVRNT(osc_page_protected(env, osc, CLM_READ, 1)); - - /* readpage queues with _COUNT_STABLE, shouldn't get here. */ - LASSERT(!(cmd & OBD_BRW_READ)); - LASSERT(osc != NULL); - page = osc->ops_cl.cpl_page; - obj = osc->ops_cl.cpl_obj; - - cl_object_attr_lock(obj); - result = cl_object_attr_get(env, obj, attr); - cl_object_attr_unlock(obj); - if (result < 0) - return result; - kms = attr->cat_kms; - if (cl_offset(obj, page->cp_index) >= kms) - /* catch race with truncate */ - return 0; - else if (cl_offset(obj, page->cp_index + 1) > kms) - /* catch sub-page write at end of file */ - return kms % CFS_PAGE_SIZE; - else - return CFS_PAGE_SIZE; +/** + * Helper function called by osc_io_submit() for every page in an immediate + * transfer (i.e., transferred synchronously). + */ +void osc_page_submit(const struct lu_env *env, struct osc_page *opg, + enum cl_req_type crt, int brw_flags) +{ + struct osc_async_page *oap = &opg->ops_oap; + struct osc_object *obj = oap->oap_obj; + + LINVRNT(osc_page_protected(env, opg, + crt == CRT_WRITE ? CLM_WRITE : CLM_READ, 1)); + + LASSERTF(oap->oap_magic == OAP_MAGIC, "Bad oap magic: oap %p, " + "magic 0x%x\n", oap, oap->oap_magic); + LASSERT(oap->oap_async_flags & ASYNC_READY); + LASSERT(oap->oap_async_flags & ASYNC_COUNT_STABLE); + + oap->oap_cmd = crt == CRT_WRITE ? OBD_BRW_WRITE : OBD_BRW_READ; + oap->oap_page_off = opg->ops_from; + oap->oap_count = opg->ops_to - opg->ops_from; + oap->oap_brw_flags = OBD_BRW_SYNC | brw_flags; + + if (osc_over_unstable_soft_limit(oap->oap_cli)) + oap->oap_brw_flags |= OBD_BRW_SOFT_SYNC; + + if (!client_is_remote(osc_export(obj)) && + cfs_capable(CFS_CAP_SYS_RESOURCE)) { + oap->oap_brw_flags |= OBD_BRW_NOQUOTA; + oap->oap_cmd |= OBD_BRW_NOQUOTA; + } + + opg->ops_submit_time = cfs_time_current(); + osc_page_transfer_get(opg, "transfer\0imm"); + osc_page_transfer_add(env, opg, crt); } -static int osc_completion(const struct lu_env *env, - void *data, int cmd, struct obdo *oa, int rc) +/* --------------- LRU page management ------------------ */ + +/* OSC is a natural place to manage LRU pages as applications are specialized + * to write OSC by OSC. Ideally, if one OSC is used more frequently it should + * occupy more LRU slots. On the other hand, we should avoid using up all LRU + * slots (client_obd::cl_lru_left) otherwise process has to be put into sleep + * for free LRU slots - this will be very bad so the algorithm requires each + * OSC to free slots voluntarily to maintain a reasonable number of free slots + * at any time. + */ + +static CFS_DECL_WAITQ(osc_lru_waitq); +static cfs_atomic_t osc_lru_waiters = CFS_ATOMIC_INIT(0); +/* LRU pages are freed in batch mode. OSC should at least free this + * number of pages to avoid running out of LRU budget, and.. */ +static const int lru_shrink_min = 2 << (20 - PAGE_CACHE_SHIFT); /* 2M */ +/* free this number at most otherwise it will take too long time to finsih. */ +static const int lru_shrink_max = 32 << (20 - PAGE_CACHE_SHIFT); /* 32M */ + +/* Check if we can free LRU slots from this OSC. If there exists LRU waiters, + * we should free slots aggressively. In this way, slots are freed in a steady + * step to maintain fairness among OSCs. + * + * Return how many LRU pages should be freed. */ +static int osc_cache_too_much(struct client_obd *cli) { - struct osc_page *opg = data; - struct osc_async_page *oap = &opg->ops_oap; - struct cl_page *page = cl_page_top(opg->ops_cl.cpl_page); - struct osc_object *obj = cl2osc(opg->ops_cl.cpl_obj); - enum cl_req_type crt; + struct cl_client_cache *cache = cli->cl_cache; + int pages = cfs_atomic_read(&cli->cl_lru_in_list) >> 1; - LINVRNT(osc_page_protected(env, opg, CLM_READ, 1)); - LINVRNT(cl_page_is_vmlocked(env, page)); + if (cfs_atomic_read(&osc_lru_waiters) > 0 && + cfs_atomic_read(cli->cl_lru_left) < lru_shrink_max) + /* drop lru pages aggressively */ + return min(pages, lru_shrink_max); - ENTRY; + /* if it's going to run out LRU slots, we should free some, but not + * too much to maintain faireness among OSCs. */ + if (cfs_atomic_read(cli->cl_lru_left) < cache->ccc_lru_max >> 4) { + unsigned long tmp; - cmd &= ~OBD_BRW_NOQUOTA; - LASSERT(equi(page->cp_state == CPS_PAGEIN, cmd == OBD_BRW_READ)); - LASSERT(equi(page->cp_state == CPS_PAGEOUT, cmd == OBD_BRW_WRITE)); - LASSERT(opg->ops_transfer_pinned); + tmp = cache->ccc_lru_max / cfs_atomic_read(&cache->ccc_users); + if (pages > tmp) + return min(pages, lru_shrink_max); - /* - * page->cp_req can be NULL if io submission failed before - * cl_req was allocated. - */ - if (page->cp_req != NULL) - cl_req_page_done(env, page); - LASSERT(page->cp_req == NULL); - - /* As the transfer for this page is being done, clear the flags */ - cfs_spin_lock(&oap->oap_lock); - oap->oap_async_flags = 0; - cfs_spin_unlock(&oap->oap_lock); - - crt = cmd == OBD_BRW_READ ? CRT_READ : CRT_WRITE; - /* Clear opg->ops_transfer_pinned before VM lock is released. */ - opg->ops_transfer_pinned = 0; - - cfs_spin_lock(&obj->oo_seatbelt); - LASSERT(opg->ops_submitter != NULL); - LASSERT(!cfs_list_empty(&opg->ops_inflight)); - cfs_list_del_init(&opg->ops_inflight); - cfs_spin_unlock(&obj->oo_seatbelt); - - opg->ops_submit_time = 0; - - cl_page_completion(env, page, crt, rc); - - /* statistic */ - if (rc == 0 && oap->oap_brw_flags & OBD_BRW_SRVLOCK) { - struct lu_device *ld = opg->ops_cl.cpl_obj->co_lu.lo_dev; - struct osc_stats *stats = &lu2osc_dev(ld)->od_stats; - int bytes = oap->oap_count; - - if (crt == CRT_READ) - stats->os_lockless_reads += bytes; - else - stats->os_lockless_writes += bytes; - } + return pages > lru_shrink_min ? lru_shrink_min : 0; + } - /* - * This has to be the last operation with the page, as locks are - * released in cl_page_completion() and nothing except for the - * reference counter protects page from concurrent reclaim. - */ - lu_ref_del(&page->cp_reference, "transfer", page); - /* - * As page->cp_obj is pinned by a reference from page->cp_req, it is - * safe to call cl_page_put() without risking object destruction in a - * non-blocking context. - */ - cl_page_put(env, page); - RETURN(0); + return 0; } -const static struct obd_async_page_ops osc_async_page_ops = { - .ap_make_ready = osc_make_ready, - .ap_refresh_count = osc_refresh_count, - .ap_completion = osc_completion -}; - -struct cl_page *osc_page_init(const struct lu_env *env, - struct cl_object *obj, - struct cl_page *page, cfs_page_t *vmpage) +/* Return how many pages are not discarded in @pvec. */ +static int discard_pagevec(const struct lu_env *env, struct cl_io *io, + struct cl_page **pvec, int max_index) { - struct osc_object *osc = cl2osc(obj); - struct osc_page *opg; - int result; - - OBD_SLAB_ALLOC_PTR_GFP(opg, osc_page_kmem, CFS_ALLOC_IO); - if (opg != NULL) { - void *oap = &opg->ops_oap; - - opg->ops_from = 0; - opg->ops_to = CFS_PAGE_SIZE; - - result = osc_prep_async_page(osc_export(osc), - NULL, osc->oo_oinfo, vmpage, - cl_offset(obj, page->cp_index), - &osc_async_page_ops, - opg, (void **)&oap, 1, NULL); - if (result == 0) { - struct osc_io *oio = osc_env_io(env); - opg->ops_srvlock = osc_io_srvlock(oio); - cl_page_slice_add(page, &opg->ops_cl, obj, - &osc_page_ops); - } - /* - * Cannot assert osc_page_protected() here as read-ahead - * creates temporary pages outside of a lock. - */ -#ifdef INVARIANT_CHECK - opg->ops_temp = !osc_page_protected(env, opg, CLM_READ, 1); -#endif - CFS_INIT_LIST_HEAD(&opg->ops_inflight); - } else - result = -ENOMEM; - return ERR_PTR(result); + int count; + int i; + + for (count = 0, i = 0; i < max_index; i++) { + struct cl_page *page = pvec[i]; + if (cl_page_own_try(env, io, page) == 0) { + /* free LRU page only if nobody is using it. + * This check is necessary to avoid freeing the pages + * having already been removed from LRU and pinned + * for IO. */ + if (!cl_page_in_use(page)) { + cl_page_unmap(env, io, page); + cl_page_discard(env, io, page); + ++count; + } + cl_page_disown(env, io, page); + } + cl_page_put(env, page); + pvec[i] = NULL; + } + return max_index - count; } /** - * Helper function called by osc_io_submit() for every page in an immediate - * transfer (i.e., transferred synchronously). + * Drop @target of pages from LRU at most. */ -void osc_io_submit_page(const struct lu_env *env, - struct osc_io *oio, struct osc_page *opg, - enum cl_req_type crt) +int osc_lru_shrink(struct client_obd *cli, int target) { - struct osc_async_page *oap = &opg->ops_oap; - struct client_obd *cli = oap->oap_cli; - int flags = 0; - - LINVRNT(osc_page_protected(env, opg, - crt == CRT_WRITE ? CLM_WRITE : CLM_READ, 1)); - - oap->oap_page_off = opg->ops_from; - oap->oap_count = opg->ops_to - opg->ops_from; - /* Give a hint to OST that requests are coming from kswapd - bug19529 */ - if (cfs_memory_pressure_get()) - oap->oap_brw_flags |= OBD_BRW_MEMALLOC; - oap->oap_brw_flags |= OBD_BRW_SYNC; - if (osc_io_srvlock(oio)) - oap->oap_brw_flags |= OBD_BRW_SRVLOCK; - - oap->oap_cmd = crt == CRT_WRITE ? OBD_BRW_WRITE : OBD_BRW_READ; - if (!client_is_remote(osc_export(cl2osc(opg->ops_cl.cpl_obj))) && - cfs_capable(CFS_CAP_SYS_RESOURCE)) { - oap->oap_brw_flags |= OBD_BRW_NOQUOTA; - oap->oap_cmd |= OBD_BRW_NOQUOTA; - } + struct cl_env_nest nest; + struct lu_env *env; + struct cl_io *io; + struct cl_object *clobj = NULL; + struct cl_page **pvec; + struct osc_page *opg; + int maxscan = 0; + int count = 0; + int index = 0; + int rc = 0; + ENTRY; + + LASSERT(cfs_atomic_read(&cli->cl_lru_in_list) >= 0); + if (cfs_atomic_read(&cli->cl_lru_in_list) == 0 || target <= 0) + RETURN(0); + + env = cl_env_nested_get(&nest); + if (IS_ERR(env)) + RETURN(PTR_ERR(env)); + + pvec = osc_env_info(env)->oti_pvec; + io = &osc_env_info(env)->oti_io; + + client_obd_list_lock(&cli->cl_lru_list_lock); + cfs_atomic_inc(&cli->cl_lru_shrinkers); + maxscan = min(target << 1, cfs_atomic_read(&cli->cl_lru_in_list)); + while (!cfs_list_empty(&cli->cl_lru_list)) { + struct cl_page *page; + + if (--maxscan < 0) + break; + + opg = cfs_list_entry(cli->cl_lru_list.next, struct osc_page, + ops_lru); + page = cl_page_top(opg->ops_cl.cpl_page); + if (cl_page_in_use_noref(page)) { + cfs_list_move_tail(&opg->ops_lru, &cli->cl_lru_list); + continue; + } + + LASSERT(page->cp_obj != NULL); + if (clobj != page->cp_obj) { + struct cl_object *tmp = page->cp_obj; + + cl_object_get(tmp); + client_obd_list_unlock(&cli->cl_lru_list_lock); + + if (clobj != NULL) { + count -= discard_pagevec(env, io, pvec, index); + index = 0; + + cl_io_fini(env, io); + cl_object_put(env, clobj); + clobj = NULL; + } + + clobj = tmp; + io->ci_obj = clobj; + io->ci_ignore_layout = 1; + rc = cl_io_init(env, io, CIT_MISC, clobj); + + client_obd_list_lock(&cli->cl_lru_list_lock); + + if (rc != 0) + break; + + ++maxscan; + continue; + } + + /* move this page to the end of list as it will be discarded + * soon. The page will be finally removed from LRU list in + * osc_page_delete(). */ + cfs_list_move_tail(&opg->ops_lru, &cli->cl_lru_list); + + /* it's okay to grab a refcount here w/o holding lock because + * it has to grab cl_lru_list_lock to delete the page. */ + cl_page_get(page); + pvec[index++] = page; + if (++count >= target) + break; + + if (unlikely(index == OTI_PVEC_SIZE)) { + client_obd_list_unlock(&cli->cl_lru_list_lock); + count -= discard_pagevec(env, io, pvec, index); + index = 0; + + client_obd_list_lock(&cli->cl_lru_list_lock); + } + } + client_obd_list_unlock(&cli->cl_lru_list_lock); + + if (clobj != NULL) { + count -= discard_pagevec(env, io, pvec, index); + + cl_io_fini(env, io); + cl_object_put(env, clobj); + } + cl_env_nested_put(&nest, env); + + cfs_atomic_dec(&cli->cl_lru_shrinkers); + RETURN(count > 0 ? count : rc); +} + +static void osc_lru_add(struct client_obd *cli, struct osc_page *opg) +{ + bool wakeup = false; + + if (!opg->ops_in_lru) + return; + + cfs_atomic_dec(&cli->cl_lru_busy); + client_obd_list_lock(&cli->cl_lru_list_lock); + if (cfs_list_empty(&opg->ops_lru)) { + cfs_list_move_tail(&opg->ops_lru, &cli->cl_lru_list); + cfs_atomic_inc_return(&cli->cl_lru_in_list); + wakeup = cfs_atomic_read(&osc_lru_waiters) > 0; + } + client_obd_list_unlock(&cli->cl_lru_list_lock); + + if (wakeup) { + osc_lru_shrink(cli, osc_cache_too_much(cli)); + wake_up_all(&osc_lru_waitq); + } +} + +/* delete page from LRUlist. The page can be deleted from LRUlist for two + * reasons: redirtied or deleted from page cache. */ +static void osc_lru_del(struct client_obd *cli, struct osc_page *opg, bool del) +{ + if (opg->ops_in_lru) { + client_obd_list_lock(&cli->cl_lru_list_lock); + if (!cfs_list_empty(&opg->ops_lru)) { + LASSERT(cfs_atomic_read(&cli->cl_lru_in_list) > 0); + cfs_list_del_init(&opg->ops_lru); + cfs_atomic_dec(&cli->cl_lru_in_list); + if (!del) + cfs_atomic_inc(&cli->cl_lru_busy); + } else if (del) { + LASSERT(cfs_atomic_read(&cli->cl_lru_busy) > 0); + cfs_atomic_dec(&cli->cl_lru_busy); + } + client_obd_list_unlock(&cli->cl_lru_list_lock); + if (del) { + cfs_atomic_inc(cli->cl_lru_left); + /* this is a great place to release more LRU pages if + * this osc occupies too many LRU pages and kernel is + * stealing one of them. + * cl_lru_shrinkers is to avoid recursive call in case + * we're already in the context of osc_lru_shrink(). */ + if (cfs_atomic_read(&cli->cl_lru_shrinkers) == 0 && + !memory_pressure_get()) + osc_lru_shrink(cli, osc_cache_too_much(cli)); + wake_up(&osc_lru_waitq); + } + } else { + LASSERT(cfs_list_empty(&opg->ops_lru)); + } +} - if (oap->oap_cmd & OBD_BRW_READ) - flags = ASYNC_COUNT_STABLE; - else if (!(oap->oap_brw_page.flag & OBD_BRW_FROM_GRANT)) - osc_enter_cache_try(env, cli, oap->oap_loi, oap, 1); +static inline int max_to_shrink(struct client_obd *cli) +{ + return min(cfs_atomic_read(&cli->cl_lru_in_list) >> 1, lru_shrink_max); +} - cfs_spin_lock(&oap->oap_lock); - oap->oap_async_flags |= OSC_FLAGS | flags; - cfs_spin_unlock(&oap->oap_lock); +static int osc_lru_reclaim(struct client_obd *cli) +{ + struct cl_client_cache *cache = cli->cl_cache; + int max_scans; + int rc; + + LASSERT(cache != NULL); + LASSERT(!cfs_list_empty(&cache->ccc_lru)); + + rc = osc_lru_shrink(cli, lru_shrink_min); + if (rc != 0) { + CDEBUG(D_CACHE, "%s: Free %d pages from own LRU: %p.\n", + cli->cl_import->imp_obd->obd_name, rc, cli); + return rc; + } + + CDEBUG(D_CACHE, "%s: cli %p no free slots, pages: %d, busy: %d.\n", + cli->cl_import->imp_obd->obd_name, cli, + cfs_atomic_read(&cli->cl_lru_in_list), + cfs_atomic_read(&cli->cl_lru_busy)); + + /* Reclaim LRU slots from other client_obd as it can't free enough + * from its own. This should rarely happen. */ + spin_lock(&cache->ccc_lru_lock); + cache->ccc_lru_shrinkers++; + cfs_list_move_tail(&cli->cl_lru_osc, &cache->ccc_lru); + + max_scans = cfs_atomic_read(&cache->ccc_users); + while (--max_scans > 0 && !cfs_list_empty(&cache->ccc_lru)) { + cli = cfs_list_entry(cache->ccc_lru.next, struct client_obd, + cl_lru_osc); + + CDEBUG(D_CACHE, "%s: cli %p LRU pages: %d, busy: %d.\n", + cli->cl_import->imp_obd->obd_name, cli, + cfs_atomic_read(&cli->cl_lru_in_list), + cfs_atomic_read(&cli->cl_lru_busy)); + + cfs_list_move_tail(&cli->cl_lru_osc, &cache->ccc_lru); + if (cfs_atomic_read(&cli->cl_lru_in_list) > 0) { + spin_unlock(&cache->ccc_lru_lock); + + rc = osc_lru_shrink(cli, max_to_shrink(cli)); + spin_lock(&cache->ccc_lru_lock); + if (rc != 0) + break; + } + } + spin_unlock(&cache->ccc_lru_lock); + + CDEBUG(D_CACHE, "%s: cli %p freed %d pages.\n", + cli->cl_import->imp_obd->obd_name, cli, rc); + return rc; +} - osc_oap_to_pending(oap); - osc_page_transfer_get(opg, "transfer\0imm"); - osc_page_transfer_add(env, opg, crt); +static int osc_lru_reserve(const struct lu_env *env, struct osc_object *obj, + struct osc_page *opg) +{ + struct l_wait_info lwi = LWI_INTR(LWI_ON_SIGNAL_NOOP, NULL); + struct client_obd *cli = osc_cli(obj); + int rc = 0; + ENTRY; + + if (cli->cl_cache == NULL) /* shall not be in LRU */ + RETURN(0); + + LASSERT(cfs_atomic_read(cli->cl_lru_left) >= 0); + while (!cfs_atomic_add_unless(cli->cl_lru_left, -1, 0)) { + int gen; + + /* run out of LRU spaces, try to drop some by itself */ + rc = osc_lru_reclaim(cli); + if (rc < 0) + break; + if (rc > 0) + continue; + + cond_resched(); + + /* slowest case, all of caching pages are busy, notifying + * other OSCs that we're lack of LRU slots. */ + cfs_atomic_inc(&osc_lru_waiters); + + gen = cfs_atomic_read(&cli->cl_lru_in_list); + rc = l_wait_event(osc_lru_waitq, + cfs_atomic_read(cli->cl_lru_left) > 0 || + (cfs_atomic_read(&cli->cl_lru_in_list) > 0 && + gen != cfs_atomic_read(&cli->cl_lru_in_list)), + &lwi); + + cfs_atomic_dec(&osc_lru_waiters); + if (rc < 0) + break; + } + + if (rc >= 0) { + cfs_atomic_inc(&cli->cl_lru_busy); + opg->ops_in_lru = 1; + rc = 0; + } + + RETURN(rc); } /** @} osc */