* Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
* Use is subject to license terms.
*
- * Copyright (c) 2011, Whamcloud, Inc.
+ * Copyright (c) 2011, 2013, Intel Corporation.
*/
/*
* This file is part of Lustre, http://www.lustre.org/
* Implementation of cl_page for OSC layer.
*
* Author: Nikita Danilov <nikita.danilov@sun.com>
+ * Author: Jinshan Xiong <jinshan.xiong@intel.com>
*/
#define DEBUG_SUBSYSTEM S_OSC
#include "osc_cl_internal.h"
-/** \addtogroup osc
- * @{
+static void osc_lru_del(struct client_obd *cli, struct osc_page *opg);
+static void osc_lru_use(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 ->
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();
- flags = LDLM_FL_TEST_LOCK | LDLM_FL_BLOCK_GRANTED;
- if (pending)
- flags |= LDLM_FL_CBPENDING;
+ 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);
- dlmmode = osc_cl_lock2ldlm(mode) | LCK_PW;
- osc_lock_build_res(env, obj, resname);
- osc_index2policy(policy, page->cp_obj, page->cp_index, page->cp_index);
- return osc_match_base(osc_export(obj), resname, LDLM_EXTENT, policy,
- dlmmode, &flags, NULL, lockh, unref);
+ flags = LDLM_FL_TEST_LOCK | LDLM_FL_BLOCK_GRANTED;
+ if (pending)
+ flags |= LDLM_FL_CBPENDING;
+
+ dlmmode = osc_cl_lock2ldlm(mode) | LCK_PW;
+ osc_lock_build_res(env, obj, resname);
+ osc_index2policy(policy, page->cp_obj, osc_index(opg), osc_index(opg));
+ return osc_match_base(osc_export(obj), resname, LDLM_EXTENT, policy,
+ dlmmode, &flags, NULL, lockh, unref);
}
/**
hdr = cl_object_header(opg->ops_cl.cpl_obj);
descr = &osc_env_info(env)->oti_descr;
descr->cld_mode = mode;
- descr->cld_start = page->cp_index;
- descr->cld_end = page->cp_index;
- cfs_spin_lock(&hdr->coh_lock_guard);
- cfs_list_for_each_entry(scan, &hdr->coh_locks, cll_linkage) {
+ descr->cld_start = osc_index(opg);
+ descr->cld_end = osc_index(opg);
+ spin_lock(&hdr->coh_lock_guard);
+ list_for_each_entry(scan, &hdr->coh_locks, cll_linkage) {
/*
* Lock-less sub-lock has to be either in HELD state
* (when io is actively going on), or in CACHED state,
break;
}
}
- cfs_spin_unlock(&hdr->coh_lock_guard);
+ spin_unlock(&hdr->coh_lock_guard);
}
return result;
}
* Page operations.
*
*/
-static void osc_page_fini(const struct lu_env *env,
- struct cl_page_slice *slice)
-{
- 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)
{
- struct cl_page *page = cl_page_top(opg->ops_cl.cpl_page);
+ struct cl_page *page = opg->ops_cl.cpl_page;
- LASSERT(!opg->ops_transfer_pinned);
- cl_page_get(page);
- lu_ref_add_atomic(&page->cp_reference, label, page);
- opg->ops_transfer_pinned = 1;
+ LASSERT(!opg->ops_transfer_pinned);
+ cl_page_get(page);
+ lu_ref_add_atomic(&page->cp_reference, label, page);
+ opg->ops_transfer_pinned = 1;
}
static void osc_page_transfer_put(const struct lu_env *env,
- struct osc_page *opg)
+ struct osc_page *opg)
{
- struct cl_page *page = cl_page_top(opg->ops_cl.cpl_page);
+ struct cl_page *page = opg->ops_cl.cpl_page;
- if (opg->ops_transfer_pinned) {
- lu_ref_del(&page->cp_reference, "transfer", page);
- opg->ops_transfer_pinned = 0;
- cl_page_put(env, page);
- }
+ if (opg->ops_transfer_pinned) {
+ opg->ops_transfer_pinned = 0;
+ lu_ref_del(&page->cp_reference, "transfer", page);
+ cl_page_put(env, page);
+ }
}
/**
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);
- 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);
+ /* ops_lru and ops_inflight share the same field, so take it from LRU
+ * first and then use it as inflight. */
+ osc_lru_use(osc_cli(obj), opg);
+
+ spin_lock(&obj->oo_seatbelt);
+ 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)
+int osc_page_cache_add(const struct lu_env *env,
+ const struct cl_page_slice *slice, struct cl_io *io)
{
struct osc_page *opg = cl2osc_page(slice);
int result;
LINVRNT(osc_page_protected(env, opg, CLM_WRITE, 0));
osc_page_transfer_get(opg, "transfer\0cache");
- result = osc_queue_async_io(env, opg);
+ 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);
+
RETURN(result);
}
policy->l_extent.end = cl_offset(obj, end + 1) - 1;
}
-static int osc_page_addref_lock(const struct lu_env *env,
- struct osc_page *opg,
- struct cl_lock *lock)
-{
- struct osc_lock *olock;
- int rc;
-
- LASSERT(opg->ops_lock == NULL);
-
- 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;
- } else {
- opg->ops_lock = lock;
- rc = 0;
- }
- return rc;
-}
-
-static void osc_page_putref_lock(const struct lu_env *env,
- struct osc_page *opg)
-{
- struct cl_lock *lock = opg->ops_lock;
- struct osc_lock *olock;
-
- LASSERT(lock != NULL);
- olock = osc_lock_at(lock);
-
- cfs_atomic_dec(&olock->ols_pageref);
- opg->ops_lock = NULL;
-
- cl_lock_put(env, lock);
-}
-
static int osc_page_is_under_lock(const struct lu_env *env,
- const struct cl_page_slice *slice,
- struct cl_io *unused)
+ const struct cl_page_slice *slice,
+ struct cl_io *unused, pgoff_t *max_index)
{
- struct cl_lock *lock;
- int result;
-
- 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;
- RETURN(result);
-}
-
-static void osc_page_disown(const struct lu_env *env,
- const struct cl_page_slice *slice,
- struct cl_io *io)
-{
- struct osc_page *opg = cl2osc_page(slice);
-
- if (unlikely(opg->ops_lock))
- osc_page_putref_lock(env, opg);
-}
-
-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);
-
- if (likely(opg->ops_lock))
- osc_page_putref_lock(env, opg);
-}
+ struct osc_page *opg = cl2osc_page(slice);
+ struct cl_lock *lock;
+ int result = -ENODATA;
+ ENTRY;
-static int osc_page_fail(const struct lu_env *env,
- const struct cl_page_slice *slice,
- struct cl_io *unused)
-{
- /*
- * Cached read?
- */
- LBUG();
- return 0;
+ *max_index = 0;
+ lock = cl_lock_at_pgoff(env, slice->cpl_obj, osc_index(opg),
+ NULL, 1, 0);
+ if (lock != NULL) {
+ *max_index = lock->cll_descr.cld_end;
+ cl_lock_put(env, lock);
+ result = 0;
+ }
+ RETURN(result);
}
-
-static const char *osc_list(cfs_list_t *head)
+static const char *osc_list(struct list_head *head)
{
- return cfs_list_empty(head) ? "-" : "+";
+ return list_empty(head) ? "-" : "+";
}
static inline cfs_time_t osc_submit_duration(struct osc_page *opg)
struct osc_object *obj = cl2osc(slice->cpl_obj);
struct client_obd *cli = &osc_export(obj)->exp_obd->u.cli;
- return (*printer)(env, cookie, LUSTRE_OSC_NAME"-page@%p: "
- "1< %#x %d %u %s %s %s > "
+ return (*printer)(env, cookie, LUSTRE_OSC_NAME"-page@%p %lu: "
+ "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 %s | %d %s %s>\n",
- opg,
+ "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, osc_index(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,
osc_list(&obj->oo_hp_ready_item),
osc_list(&obj->oo_write_item),
osc_list(&obj->oo_read_item),
- obj->oo_read_pages.oop_num_pending,
- osc_list(&obj->oo_read_pages.oop_pending),
- osc_list(&obj->oo_read_pages.oop_urgent),
- obj->oo_write_pages.oop_num_pending,
- osc_list(&obj->oo_write_pages.oop_pending),
- osc_list(&obj->oo_write_pages.oop_urgent));
+ atomic_read(&obj->oo_nr_reads),
+ osc_list(&obj->oo_reading_exts),
+ 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,
ENTRY;
CDEBUG(D_TRACE, "%p\n", opg);
osc_page_transfer_put(env, opg);
- rc = osc_teardown_async_page(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;
+ rc = osc_teardown_async_page(env, obj, opg);
+ if (rc) {
+ CL_PAGE_DEBUG(D_ERROR, env, slice->cpl_page,
+ "Trying to teardown failed: %d\n", rc);
+ LASSERT(0);
+ }
+
+ spin_lock(&obj->oo_seatbelt);
+ if (opg->ops_submitter != NULL) {
+ LASSERT(!list_empty(&opg->ops_inflight));
+ list_del_init(&opg->ops_inflight);
+ opg->ops_submitter = NULL;
+ }
+ spin_unlock(&obj->oo_seatbelt);
+
+ osc_lru_del(osc_cli(obj), opg);
+
+ if (slice->cpl_page->cp_type == CPT_CACHEABLE) {
+ void *value;
+
+ spin_lock(&obj->oo_tree_lock);
+ value = radix_tree_delete(&obj->oo_tree, osc_index(opg));
+ if (value != NULL)
+ --obj->oo_npages;
+ spin_unlock(&obj->oo_tree_lock);
+
+ LASSERT(ergo(value != NULL, value == opg));
+ }
+
+ EXIT;
}
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_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,
- .cpo_delete = osc_page_delete,
- .cpo_is_under_lock = osc_page_is_under_lock,
- .cpo_disown = osc_page_disown,
- .io = {
- [CRT_READ] = {
- .cpo_cache_add = osc_page_fail,
- .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_print = osc_page_print,
+ .cpo_delete = osc_page_delete,
+ .cpo_is_under_lock = osc_page_is_under_lock,
+ .cpo_clip = osc_page_clip,
+ .cpo_cancel = osc_page_cancel,
+ .cpo_flush = osc_page_flush
};
-struct cl_page *osc_page_init(const struct lu_env *env,
- struct cl_object *obj,
- struct cl_page *page, cfs_page_t *vmpage)
+int osc_page_init(const struct lu_env *env, struct cl_object *obj,
+ struct cl_page *page, pgoff_t index)
{
- struct osc_object *osc = cl2osc(obj);
- struct osc_page *opg;
- int result;
+ struct osc_object *osc = cl2osc(obj);
+ struct osc_page *opg = cl_object_page_slice(obj, page);
+ int result;
- OBD_SLAB_ALLOC_PTR_GFP(opg, osc_page_kmem, CFS_ALLOC_IO);
- if (opg != NULL) {
- opg->ops_from = 0;
- opg->ops_to = CFS_PAGE_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 INVARIANT_CHECK
- opg->ops_temp = !osc_page_protected(env, opg, CLM_READ, 1);
+ opg->ops_from = 0;
+ opg->ops_to = PAGE_CACHE_SIZE;
+
+ result = osc_prep_async_page(osc, opg, page->cp_vmpage,
+ cl_offset(obj, 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, index,
+ &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
- CFS_INIT_LIST_HEAD(&opg->ops_inflight);
- } else
- result = -ENOMEM;
- return ERR_PTR(result);
+ /* ops_inflight and ops_lru are the same field, but it doesn't
+ * hurt to initialize it twice :-) */
+ INIT_LIST_HEAD(&opg->ops_inflight);
+ INIT_LIST_HEAD(&opg->ops_lru);
+
+ /* reserve an LRU space for this page */
+ if (page->cp_type == CPT_CACHEABLE && result == 0) {
+ result = osc_lru_reserve(env, osc, opg);
+ if (result == 0) {
+ spin_lock(&osc->oo_tree_lock);
+ result = radix_tree_insert(&osc->oo_tree, index, opg);
+ if (result == 0)
+ ++osc->oo_npages;
+ spin_unlock(&osc->oo_tree_lock);
+ LASSERT(result == 0);
+ }
+ }
+
+ return result;
}
/**
* Helper function called by osc_io_submit() for every page in an immediate
* transfer (i.e., transferred synchronously).
*/
-void osc_io_submit_page(const struct lu_env *env,
- struct osc_io *oio, struct osc_page *opg,
- enum cl_req_type crt)
+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 (!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);
+}
+
+/* --------------- 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);
+/* 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 = 8 << (20 - PAGE_CACHE_SHIFT); /* 8M */
+
+/* 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 cl_client_cache *cache = cli->cl_cache;
+ int pages = atomic_read(&cli->cl_lru_in_list);
+ unsigned long budget;
+
+ budget = cache->ccc_lru_max / atomic_read(&cache->ccc_users);
+
+ /* if it's going to run out LRU slots, we should free some, but not
+ * too much to maintain faireness among OSCs. */
+ if (atomic_read(cli->cl_lru_left) < cache->ccc_lru_max >> 4) {
+ if (pages >= budget)
+ return lru_shrink_max;
+ else if (pages >= budget / 2)
+ return lru_shrink_min;
+ } else if (pages >= budget * 2)
+ return lru_shrink_min;
+ return 0;
+}
+
+int lru_queue_work(const struct lu_env *env, void *data)
+{
+ struct client_obd *cli = data;
+
+ CDEBUG(D_CACHE, "Run LRU work for client obd %p.\n", cli);
+
+ if (osc_cache_too_much(cli))
+ osc_lru_shrink(env, cli, lru_shrink_max, true);
+
+ RETURN(0);
+}
+
+void osc_lru_add_batch(struct client_obd *cli, struct list_head *plist)
+{
+ struct list_head lru = LIST_HEAD_INIT(lru);
+ struct osc_async_page *oap;
+ int npages = 0;
+
+ list_for_each_entry(oap, plist, oap_pending_item) {
+ struct osc_page *opg = oap2osc_page(oap);
+
+ if (!opg->ops_in_lru)
+ continue;
+
+ ++npages;
+ LASSERT(list_empty(&opg->ops_lru));
+ list_add(&opg->ops_lru, &lru);
+ }
+
+ if (npages > 0) {
+ client_obd_list_lock(&cli->cl_lru_list_lock);
+ list_splice_tail(&lru, &cli->cl_lru_list);
+ atomic_sub(npages, &cli->cl_lru_busy);
+ atomic_add(npages, &cli->cl_lru_in_list);
+ client_obd_list_unlock(&cli->cl_lru_list_lock);
+
+ /* XXX: May set force to be true for better performance */
+ if (osc_cache_too_much(cli))
+ (void)ptlrpcd_queue_work(cli->cl_lru_work);
+ }
+}
+
+static void __osc_lru_del(struct client_obd *cli, struct osc_page *opg)
+{
+ LASSERT(atomic_read(&cli->cl_lru_in_list) > 0);
+ list_del_init(&opg->ops_lru);
+ atomic_dec(&cli->cl_lru_in_list);
+}
+
+/**
+ * Page is being destroyed. The page may be not in LRU list, if the transfer
+ * has never finished(error occurred).
+ */
+static void osc_lru_del(struct client_obd *cli, struct osc_page *opg)
+{
+ if (opg->ops_in_lru) {
+ client_obd_list_lock(&cli->cl_lru_list_lock);
+ if (!list_empty(&opg->ops_lru)) {
+ __osc_lru_del(cli, opg);
+ } else {
+ LASSERT(atomic_read(&cli->cl_lru_busy) > 0);
+ atomic_dec(&cli->cl_lru_busy);
+ }
+ client_obd_list_unlock(&cli->cl_lru_list_lock);
+
+ 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. */
+ if (!memory_pressure_get())
+ (void)ptlrpcd_queue_work(cli->cl_lru_work);
+ wake_up(&osc_lru_waitq);
+ } else {
+ LASSERT(list_empty(&opg->ops_lru));
+ }
+}
+
+/**
+ * Delete page from LRUlist for redirty.
+ */
+static void osc_lru_use(struct client_obd *cli, struct osc_page *opg)
+{
+ /* If page is being transfered for the first time,
+ * ops_lru should be empty */
+ if (opg->ops_in_lru && !list_empty(&opg->ops_lru)) {
+ client_obd_list_lock(&cli->cl_lru_list_lock);
+ __osc_lru_del(cli, opg);
+ client_obd_list_unlock(&cli->cl_lru_list_lock);
+ atomic_inc(&cli->cl_lru_busy);
+ }
+}
+
+static void discard_pagevec(const struct lu_env *env, struct cl_io *io,
+ struct cl_page **pvec, int max_index)
+{
+ int i;
+
+ for (i = 0; i < max_index; i++) {
+ struct cl_page *page = pvec[i];
+
+ LASSERT(cl_page_is_owned(page, io));
+ cl_page_discard(env, io, page);
+ cl_page_disown(env, io, page);
+ cl_page_put(env, page);
+
+ pvec[i] = NULL;
+ }
+}
+
+/**
+ * Check if a cl_page can be released, i.e, it's not being used.
+ *
+ * If unstable account is turned on, bulk transfer may hold one refcount
+ * for recovery so we need to check vmpage refcount as well; otherwise,
+ * even we can destroy cl_page but the corresponding vmpage can't be reused.
+ */
+static inline bool lru_page_busy(struct client_obd *cli, struct cl_page *page)
+{
+ if (cl_page_in_use_noref(page))
+ return true;
+
+ if (cli->cl_cache->ccc_unstable_check) {
+ struct page *vmpage = cl_page_vmpage(page);
+
+ /* vmpage have two known users: cl_page and VM page cache */
+ if (page_count(vmpage) - page_mapcount(vmpage) > 2)
+ return true;
+ }
+ return false;
+}
+
+/**
+ * Drop @target of pages from LRU at most.
+ */
+int osc_lru_shrink(const struct lu_env *env, struct client_obd *cli,
+ int target, bool force)
+{
+ 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(atomic_read(&cli->cl_lru_in_list) >= 0);
+ if (atomic_read(&cli->cl_lru_in_list) == 0 || target <= 0)
+ RETURN(0);
+
+ if (!force) {
+ if (atomic_read(&cli->cl_lru_shrinkers) > 0)
+ RETURN(-EBUSY);
+
+ if (atomic_inc_return(&cli->cl_lru_shrinkers) > 1) {
+ atomic_dec(&cli->cl_lru_shrinkers);
+ RETURN(-EBUSY);
+ }
+ } else {
+ atomic_inc(&cli->cl_lru_shrinkers);
+ }
+
+ pvec = (struct cl_page **)osc_env_info(env)->oti_pvec;
+ io = &osc_env_info(env)->oti_io;
+
+ client_obd_list_lock(&cli->cl_lru_list_lock);
+ maxscan = min(target << 1, atomic_read(&cli->cl_lru_in_list));
+ while (!list_empty(&cli->cl_lru_list)) {
+ struct cl_page *page;
+ bool will_free = false;
+
+ if (--maxscan < 0)
+ break;
+
+ opg = list_entry(cli->cl_lru_list.next, struct osc_page,
+ ops_lru);
+ page = opg->ops_cl.cpl_page;
+ if (lru_page_busy(cli, page)) {
+ 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) {
+ 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;
+ }
+
+ if (cl_page_own_try(env, io, page) == 0) {
+ if (!lru_page_busy(cli, page)) {
+ /* remove it from lru list earlier to avoid
+ * lock contention */
+ __osc_lru_del(cli, opg);
+ opg->ops_in_lru = 0; /* will be discarded */
+
+ cl_page_get(page);
+ will_free = true;
+ } else {
+ cl_page_disown(env, io, page);
+ }
+ }
+
+ if (!will_free) {
+ list_move_tail(&opg->ops_lru, &cli->cl_lru_list);
+ continue;
+ }
+
+ /* Don't discard and free the page with cl_lru_list held */
+ pvec[index++] = page;
+ if (unlikely(index == OTI_PVEC_SIZE)) {
+ client_obd_list_unlock(&cli->cl_lru_list_lock);
+ discard_pagevec(env, io, pvec, index);
+ index = 0;
+
+ client_obd_list_lock(&cli->cl_lru_list_lock);
+ }
+
+ if (++count >= target)
+ break;
+ }
+ client_obd_list_unlock(&cli->cl_lru_list_lock);
+
+ if (clobj != NULL) {
+ discard_pagevec(env, io, pvec, index);
+
+ cl_io_fini(env, io);
+ cl_object_put(env, clobj);
+ }
+
+ atomic_dec(&cli->cl_lru_shrinkers);
+ if (count > 0) {
+ atomic_add(count, cli->cl_lru_left);
+ wake_up_all(&osc_lru_waitq);
+ }
+ RETURN(count > 0 ? count : rc);
+}
+
+static inline int max_to_shrink(struct client_obd *cli)
+{
+ return min(atomic_read(&cli->cl_lru_in_list) >> 1, lru_shrink_max);
+}
+
+int osc_lru_reclaim(struct client_obd *cli)
+{
+ struct cl_env_nest nest;
+ struct lu_env *env;
+ struct cl_client_cache *cache = cli->cl_cache;
+ int max_scans;
+ int rc = 0;
+ ENTRY;
+
+ LASSERT(cache != NULL);
+ LASSERT(!list_empty(&cache->ccc_lru));
+
+ env = cl_env_nested_get(&nest);
+ if (IS_ERR(env))
+ RETURN(rc);
+
+ rc = osc_lru_shrink(env, cli, osc_cache_too_much(cli), false);
+ if (rc != 0) {
+ if (rc == -EBUSY)
+ rc = 0;
+
+ CDEBUG(D_CACHE, "%s: Free %d pages from own LRU: %p.\n",
+ cli->cl_import->imp_obd->obd_name, rc, cli);
+ GOTO(out, rc);
+ }
+
+ CDEBUG(D_CACHE, "%s: cli %p no free slots, pages: %d, busy: %d.\n",
+ cli->cl_import->imp_obd->obd_name, cli,
+ atomic_read(&cli->cl_lru_in_list),
+ 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++;
+ list_move_tail(&cli->cl_lru_osc, &cache->ccc_lru);
+
+ max_scans = atomic_read(&cache->ccc_users);
+ while (--max_scans > 0 && !list_empty(&cache->ccc_lru)) {
+ cli = 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,
+ atomic_read(&cli->cl_lru_in_list),
+ atomic_read(&cli->cl_lru_busy));
+
+ list_move_tail(&cli->cl_lru_osc, &cache->ccc_lru);
+ if (osc_cache_too_much(cli) > 0) {
+ spin_unlock(&cache->ccc_lru_lock);
+
+ rc = osc_lru_shrink(env, cli, osc_cache_too_much(cli),
+ true);
+ spin_lock(&cache->ccc_lru_lock);
+ if (rc != 0)
+ break;
+ }
+ }
+ spin_unlock(&cache->ccc_lru_lock);
+
+out:
+ cl_env_nested_put(&nest, env);
+ CDEBUG(D_CACHE, "%s: cli %p freed %d pages.\n",
+ cli->cl_import->imp_obd->obd_name, cli, rc);
+ return rc;
+}
+
+/**
+ * osc_lru_reserve() is called to reserve an LRU slot for a cl_page.
+ *
+ * Usually the LRU slots are reserved in osc_io_iter_rw_init().
+ * Only in the case that the LRU slots are in extreme shortage, it should
+ * have reserved enough slots for an IO.
+ */
+static int osc_lru_reserve(const struct lu_env *env, struct osc_object *obj,
+ struct osc_page *opg)
{
- LINVRNT(osc_page_protected(env, opg,
- crt == CRT_WRITE ? CLM_WRITE : CLM_READ, 1));
+ struct l_wait_info lwi = LWI_INTR(LWI_ON_SIGNAL_NOOP, NULL);
+ struct osc_io *oio = osc_env_io(env);
+ struct client_obd *cli = osc_cli(obj);
+ int rc = 0;
+ ENTRY;
+
+ if (cli->cl_cache == NULL) /* shall not be in LRU */
+ RETURN(0);
+
+ if (oio->oi_lru_reserved > 0) {
+ --oio->oi_lru_reserved;
+ goto out;
+ }
+
+ LASSERT(atomic_read(cli->cl_lru_left) >= 0);
+ while (!atomic_add_unless(cli->cl_lru_left, -1, 0)) {
+
+ /* 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();
+ rc = l_wait_event(osc_lru_waitq,
+ atomic_read(cli->cl_lru_left) > 0,
+ &lwi);
+ if (rc < 0)
+ break;
+ }
+
+out:
+ if (rc >= 0) {
+ atomic_inc(&cli->cl_lru_busy);
+ opg->ops_in_lru = 1;
+ rc = 0;
+ }
+
+ RETURN(rc);
+}
+
+/**
+ * Atomic operations are expensive. We accumulate the accounting for the
+ * same page zone to get better performance.
+ * In practice this can work pretty good because the pages in the same RPC
+ * are likely from the same page zone.
+ */
+static inline void unstable_page_accounting(struct ptlrpc_bulk_desc *desc,
+ int factor)
+{
+ obd_count page_count = desc->bd_iov_count;
+ void *zone = NULL;
+ int count = 0;
+ int i;
+
+ for (i = 0; i < page_count; i++) {
+ void *pz = page_zone(desc->bd_iov[i].kiov_page);
+
+ if (likely(pz == zone)) {
+ ++count;
+ continue;
+ }
+
+ if (count > 0) {
+ mod_zone_page_state(zone, NR_UNSTABLE_NFS,
+ factor * count);
+ count = 0;
+ }
+ zone = pz;
+ ++count;
+ }
+ if (count > 0)
+ mod_zone_page_state(zone, NR_UNSTABLE_NFS, factor * count);
+}
+
+static inline void add_unstable_page_accounting(struct ptlrpc_bulk_desc *desc)
+{
+ unstable_page_accounting(desc, 1);
+}
+
+static inline void dec_unstable_page_accounting(struct ptlrpc_bulk_desc *desc)
+{
+ unstable_page_accounting(desc, -1);
+}
+
+/**
+ * Performs "unstable" page accounting. This function balances the
+ * increment operations performed in osc_inc_unstable_pages. It is
+ * registered as the RPC request callback, and is executed when the
+ * bulk RPC is committed on the server. Thus at this point, the pages
+ * involved in the bulk transfer are no longer considered unstable.
+ *
+ * If this function is called, the request should have been committed
+ * or req:rq_unstable must have been set; it implies that the unstable
+ * statistic have been added.
+ */
+void osc_dec_unstable_pages(struct ptlrpc_request *req)
+{
+ struct ptlrpc_bulk_desc *desc = req->rq_bulk;
+ struct client_obd *cli = &req->rq_import->imp_obd->u.cli;
+ obd_count page_count = desc->bd_iov_count;
+ int unstable_count;
+
+ LASSERT(page_count >= 0);
+ dec_unstable_page_accounting(desc);
+
+ unstable_count = atomic_sub_return(page_count, &cli->cl_unstable_count);
+ LASSERT(unstable_count >= 0);
+
+ unstable_count = atomic_sub_return(page_count,
+ &cli->cl_cache->ccc_unstable_nr);
+ LASSERT(unstable_count >= 0);
+ if (unstable_count == 0)
+ wake_up_all(&cli->cl_cache->ccc_unstable_waitq);
+
+ if (osc_cache_too_much(cli))
+ (void)ptlrpcd_queue_work(cli->cl_lru_work);
+}
+
+/**
+ * "unstable" page accounting. See: osc_dec_unstable_pages.
+ */
+void osc_inc_unstable_pages(struct ptlrpc_request *req)
+{
+ struct ptlrpc_bulk_desc *desc = req->rq_bulk;
+ struct client_obd *cli = &req->rq_import->imp_obd->u.cli;
+ obd_count page_count = desc->bd_iov_count;
+
+ /* No unstable page tracking */
+ if (cli->cl_cache == NULL || !cli->cl_cache->ccc_unstable_check)
+ return;
+
+ add_unstable_page_accounting(desc);
+ atomic_add(page_count, &cli->cl_unstable_count);
+ atomic_add(page_count, &cli->cl_cache->ccc_unstable_nr);
+
+ /* If the request has already been committed (i.e. brw_commit
+ * called via rq_commit_cb), we need to undo the unstable page
+ * increments we just performed because rq_commit_cb wont be
+ * called again. */
+ spin_lock(&req->rq_lock);
+ if (unlikely(req->rq_committed)) {
+ spin_unlock(&req->rq_lock);
+
+ osc_dec_unstable_pages(req);
+ } else {
+ req->rq_unstable = 1;
+ spin_unlock(&req->rq_lock);
+ }
+}
+
+/**
+ * Check if it piggybacks SOFT_SYNC flag to OST from this OSC.
+ * This function will be called by every BRW RPC so it's critical
+ * to make this function fast.
+ */
+bool osc_over_unstable_soft_limit(struct client_obd *cli)
+{
+ long unstable_nr, osc_unstable_count;
+
+ /* Can't check cli->cl_unstable_count, therefore, no soft limit */
+ if (cli->cl_cache == NULL || !cli->cl_cache->ccc_unstable_check)
+ return false;
+
+ osc_unstable_count = atomic_read(&cli->cl_unstable_count);
+ unstable_nr = atomic_read(&cli->cl_cache->ccc_unstable_nr);
- osc_queue_sync_page(env, opg,
- crt == CRT_WRITE ? OBD_BRW_WRITE : OBD_BRW_READ,
- osc_io_srvlock(oio) ? OBD_BRW_SRVLOCK : 0);
+ CDEBUG(D_CACHE,
+ "%s: cli: %p unstable pages: %lu, osc unstable pages: %lu\n",
+ cli->cl_import->imp_obd->obd_name, cli,
+ unstable_nr, osc_unstable_count);
- osc_page_transfer_get(opg, "transfer\0imm");
- osc_page_transfer_add(env, opg, crt);
+ /* If the LRU slots are in shortage - 25% remaining AND this OSC
+ * has one full RPC window of unstable pages, it's a good chance
+ * to piggyback a SOFT_SYNC flag.
+ * Please notice that the OST won't take immediate response for the
+ * SOFT_SYNC request so active OSCs will have more chance to carry
+ * the flag, this is reasonable. */
+ return unstable_nr > cli->cl_cache->ccc_lru_max >> 2 &&
+ osc_unstable_count > cli->cl_max_pages_per_rpc *
+ cli->cl_max_rpcs_in_flight;
}
/** @} osc */