[PATCH 05/43] staging/lustre/osc: Adjustment on osc LRU for performance

From: green
Date: Wed Mar 30 2016 - 13:03:08 EST

From: Jinshan Xiong <jinshan.xiong@xxxxxxxxx>

Add and discard pages from LRU in batch.

Signed-off-by: Jinshan Xiong <jinshan.xiong@xxxxxxxxx>
Reviewed-on: http://review.whamcloud.com/7890
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-3321
Reviewed-by: Niu Yawei <yawei.niu@xxxxxxxxx>
Reviewed-by: Lai Siyao <lai.siyao@xxxxxxxxx>
Signed-off-by: Oleg Drokin <green@xxxxxxxxxxxxxx>
---
drivers/staging/lustre/lustre/llite/llite_lib.c | 5 +-
drivers/staging/lustre/lustre/osc/lproc_osc.c | 2 +-
drivers/staging/lustre/lustre/osc/osc_cache.c | 2 +
.../staging/lustre/lustre/osc/osc_cl_internal.h | 26 +-
drivers/staging/lustre/lustre/osc/osc_internal.h | 3 +-
drivers/staging/lustre/lustre/osc/osc_io.c | 51 ++++
drivers/staging/lustre/lustre/osc/osc_page.c | 301 +++++++++++----------
drivers/staging/lustre/lustre/osc/osc_request.c | 2 +-
8 files changed, 235 insertions(+), 157 deletions(-)

diff --git a/drivers/staging/lustre/lustre/llite/llite_lib.c b/drivers/staging/lustre/lustre/llite/llite_lib.c
index 673d31e..a4401f2 100644
--- a/drivers/staging/lustre/lustre/llite/llite_lib.c
+++ b/drivers/staging/lustre/lustre/llite/llite_lib.c
@@ -85,10 +85,7 @@ static struct ll_sb_info *ll_init_sbi(struct super_block *sb)

si_meminfo(&si);
pages = si.totalram - si.totalhigh;
- if (pages >> (20 - PAGE_CACHE_SHIFT) < 512)
- lru_page_max = pages / 2;
- else
- lru_page_max = (pages / 4) * 3;
+ lru_page_max = pages / 2;

/* initialize lru data */
atomic_set(&sbi->ll_cache.ccc_users, 0);
diff --git a/drivers/staging/lustre/lustre/osc/lproc_osc.c b/drivers/staging/lustre/lustre/osc/lproc_osc.c
index 57c43c5..3eff12c 100644
--- a/drivers/staging/lustre/lustre/osc/lproc_osc.c
+++ b/drivers/staging/lustre/lustre/osc/lproc_osc.c
@@ -223,7 +223,7 @@ static ssize_t osc_cached_mb_seq_write(struct file *file,

rc = atomic_read(&cli->cl_lru_in_list) - pages_number;
if (rc > 0)
- (void)osc_lru_shrink(cli, rc);
+ (void)osc_lru_shrink(cli, rc, true);

return count;
}
diff --git a/drivers/staging/lustre/lustre/osc/osc_cache.c b/drivers/staging/lustre/lustre/osc/osc_cache.c
index 3cfd2b0..6196c3b 100644
--- a/drivers/staging/lustre/lustre/osc/osc_cache.c
+++ b/drivers/staging/lustre/lustre/osc/osc_cache.c
@@ -856,6 +856,8 @@ int osc_extent_finish(const struct lu_env *env, struct osc_extent *ext,

ext->oe_rc = rc ?: ext->oe_nr_pages;
EASSERT(ergo(rc == 0, ext->oe_state == OES_RPC), ext);
+
+ osc_lru_add_batch(cli, &ext->oe_pages);
list_for_each_entry_safe(oap, tmp, &ext->oe_pages, oap_pending_item) {
list_del_init(&oap->oap_rpc_item);
list_del_init(&oap->oap_pending_item);
diff --git a/drivers/staging/lustre/lustre/osc/osc_cl_internal.h b/drivers/staging/lustre/lustre/osc/osc_cl_internal.h
index d55d04d..f516848 100644
--- a/drivers/staging/lustre/lustre/osc/osc_cl_internal.h
+++ b/drivers/staging/lustre/lustre/osc/osc_cl_internal.h
@@ -77,6 +77,8 @@ struct osc_io {
*/
struct osc_extent *oi_trunc;

+ int oi_lru_reserved;
+
struct obd_info oi_info;
struct obdo oi_oa;
struct osc_async_cbargs {
@@ -100,7 +102,7 @@ struct osc_session {
struct osc_io os_io;
};

-#define OTI_PVEC_SIZE 64
+#define OTI_PVEC_SIZE 256
struct osc_thread_info {
struct ldlm_res_id oti_resname;
ldlm_policy_data_t oti_policy;
@@ -369,18 +371,15 @@ struct osc_page {
* Set if the page must be transferred with OBD_BRW_SRVLOCK.
*/
ops_srvlock:1;
- union {
- /**
- * lru page list. ops_inflight and ops_lru are exclusive so
- * that they can share the same data.
- */
- struct list_head ops_lru;
- /**
- * Linkage into a per-osc_object list of pages in flight. For
- * debugging.
- */
- struct list_head ops_inflight;
- };
+ /**
+ * lru page list. See osc_lru_{del|use}() in osc_page.c for usage.
+ */
+ struct list_head ops_lru;
+ /**
+ * Linkage into a per-osc_object list of pages in flight. For
+ * debugging.
+ */
+ struct list_head ops_inflight;
/**
* Thread that submitted this page for transfer. For debugging.
*/
@@ -432,6 +431,7 @@ void osc_index2policy (ldlm_policy_data_t *policy, const struct cl_object *obj,
int osc_lvb_print (const struct lu_env *env, void *cookie,
lu_printer_t p, const struct ost_lvb *lvb);

+void osc_lru_add_batch(struct client_obd *cli, struct list_head *list);
void osc_page_submit(const struct lu_env *env, struct osc_page *opg,
enum cl_req_type crt, int brw_flags);
int osc_cancel_async_page(const struct lu_env *env, struct osc_page *ops);
diff --git a/drivers/staging/lustre/lustre/osc/osc_internal.h b/drivers/staging/lustre/lustre/osc/osc_internal.h
index ea695c2..ec12962 100644
--- a/drivers/staging/lustre/lustre/osc/osc_internal.h
+++ b/drivers/staging/lustre/lustre/osc/osc_internal.h
@@ -130,7 +130,8 @@ int osc_sync_base(struct obd_export *exp, struct obd_info *oinfo,
int osc_process_config_base(struct obd_device *obd, struct lustre_cfg *cfg);
int osc_build_rpc(const struct lu_env *env, struct client_obd *cli,
struct list_head *ext_list, int cmd);
-int osc_lru_shrink(struct client_obd *cli, int target);
+int osc_lru_shrink(struct client_obd *cli, int target, bool force);
+int osc_lru_reclaim(struct client_obd *cli);

extern spinlock_t osc_ast_guard;

diff --git a/drivers/staging/lustre/lustre/osc/osc_io.c b/drivers/staging/lustre/lustre/osc/osc_io.c
index 6bd0a45..a0fa533 100644
--- a/drivers/staging/lustre/lustre/osc/osc_io.c
+++ b/drivers/staging/lustre/lustre/osc/osc_io.c
@@ -308,6 +308,55 @@ static int osc_io_commit_write(const struct lu_env *env,
return 0;
}

+static int osc_io_rw_iter_init(const struct lu_env *env,
+ const struct cl_io_slice *ios)
+{
+ struct cl_io *io = ios->cis_io;
+ struct osc_io *oio = osc_env_io(env);
+ struct osc_object *osc = cl2osc(ios->cis_obj);
+ struct client_obd *cli = osc_cli(osc);
+ unsigned long c;
+ unsigned int npages;
+ unsigned int max_pages;
+
+ if (cl_io_is_append(io))
+ return 0;
+
+ npages = io->u.ci_rw.crw_count >> PAGE_CACHE_SHIFT;
+ if (io->u.ci_rw.crw_pos & ~PAGE_MASK)
+ ++npages;
+
+ max_pages = cli->cl_max_pages_per_rpc * cli->cl_max_rpcs_in_flight;
+ if (npages > max_pages)
+ npages = max_pages;
+
+ c = atomic_read(cli->cl_lru_left);
+ if (c < npages && osc_lru_reclaim(cli) > 0)
+ c = atomic_read(cli->cl_lru_left);
+ while (c >= npages) {
+ if (c == atomic_cmpxchg(cli->cl_lru_left, c, c - npages)) {
+ oio->oi_lru_reserved = npages;
+ break;
+ }
+ c = atomic_read(cli->cl_lru_left);
+ }
+
+ return 0;
+}
+
+static void osc_io_rw_iter_fini(const struct lu_env *env,
+ const struct cl_io_slice *ios)
+{
+ struct osc_io *oio = osc_env_io(env);
+ struct osc_object *osc = cl2osc(ios->cis_obj);
+ struct client_obd *cli = osc_cli(osc);
+
+ if (oio->oi_lru_reserved > 0) {
+ atomic_add(oio->oi_lru_reserved, cli->cl_lru_left);
+ oio->oi_lru_reserved = 0;
+ }
+}
+
static int osc_io_fault_start(const struct lu_env *env,
const struct cl_io_slice *ios)
{
@@ -650,6 +699,8 @@ static const struct cl_io_operations osc_io_ops = {
.cio_fini = osc_io_fini
},
[CIT_WRITE] = {
+ .cio_iter_init = osc_io_rw_iter_init,
+ .cio_iter_fini = osc_io_rw_iter_fini,
.cio_start = osc_io_write_start,
.cio_end = osc_io_end,
.cio_fini = osc_io_fini
diff --git a/drivers/staging/lustre/lustre/osc/osc_page.c b/drivers/staging/lustre/lustre/osc/osc_page.c
index d720b1a..a60b783 100644
--- a/drivers/staging/lustre/lustre/osc/osc_page.c
+++ b/drivers/staging/lustre/lustre/osc/osc_page.c
@@ -42,8 +42,8 @@

#include "osc_cl_internal.h"

-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 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);

@@ -104,10 +104,7 @@ static void osc_page_transfer_add(const struct lu_env *env,
{
struct osc_object *obj = cl2osc(opg->ops_cl.cpl_obj);

- /* 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);
+ osc_lru_use(osc_cli(obj), opg);

spin_lock(&obj->oo_seatbelt);
list_add(&opg->ops_inflight, &obj->oo_inflight[crt]);
@@ -222,21 +219,15 @@ static void osc_page_completion_read(const struct lu_env *env,
int ioret)
{
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);
- 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,
@@ -334,7 +325,7 @@ static void osc_page_delete(const struct lu_env *env,
}
spin_unlock(&obj->oo_seatbelt);

- osc_lru_del(osc_cli(obj), opg, true);
+ osc_lru_del(osc_cli(obj), opg);
}

static void osc_page_clip(const struct lu_env *env,
@@ -483,13 +474,12 @@ void osc_page_submit(const struct lu_env *env, struct osc_page *opg,
*/

static DECLARE_WAIT_QUEUE_HEAD(osc_lru_waitq);
-static atomic_t osc_lru_waiters = 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 finish. */
-static const int lru_shrink_max = 32 << (20 - PAGE_CACHE_SHIFT); /* 32M */
+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
@@ -500,62 +490,127 @@ static const int lru_shrink_max = 32 << (20 - PAGE_CACHE_SHIFT); /* 32M */
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) >> 1;
+ int pages = atomic_read(&cli->cl_lru_in_list);
+ unsigned long budget;

- if (atomic_read(&osc_lru_waiters) > 0 &&
- atomic_read(cli->cl_lru_left) < lru_shrink_max)
- /* drop lru pages aggressively */
- return min(pages, lru_shrink_max);
+ 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 fairness among OSCs.
*/
if (atomic_read(cli->cl_lru_left) < cache->ccc_lru_max >> 4) {
- unsigned long tmp;
+ 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;
+}

- tmp = cache->ccc_lru_max / atomic_read(&cache->ccc_users);
- if (pages > tmp)
- return min(pages, lru_shrink_max);
+void osc_lru_add_batch(struct client_obd *cli, struct list_head *plist)
+{
+ LIST_HEAD(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;

- return pages > lru_shrink_min ? lru_shrink_min : 0;
+ ++npages;
+ LASSERT(list_empty(&opg->ops_lru));
+ list_add(&opg->ops_lru, &lru);
}

- return 0;
+ 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 */
+ osc_lru_shrink(cli, osc_cache_too_much(cli), false);
+ }
}

-/* 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)
+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())
+ osc_lru_shrink(cli, osc_cache_too_much(cli), false);
+ 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 transferred 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 count;
int i;

- for (count = 0, i = 0; i < max_index; i++) {
+ for (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);
- }
+ LASSERT(cl_page_is_owned(page, io));
+ cl_page_unmap(env, io, page);
+ cl_page_discard(env, io, page);
+ cl_page_disown(env, io, page);
cl_page_put(env, page);
+
pvec[i] = NULL;
}
- return max_index - count;
}

/**
* Drop @target of pages from LRU at most.
*/
-int osc_lru_shrink(struct client_obd *cli, int target)
+int osc_lru_shrink(struct client_obd *cli, int target, bool force)
{
struct cl_env_nest nest;
struct lu_env *env;
@@ -573,18 +628,32 @@ int osc_lru_shrink(struct client_obd *cli, int target)
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);
+ }
+
env = cl_env_nested_get(&nest);
- if (IS_ERR(env))
- return PTR_ERR(env);
+ if (IS_ERR(env)) {
+ rc = PTR_ERR(env);
+ goto out;
+ }

pvec = osc_env_info(env)->oti_pvec;
io = &osc_env_info(env)->oti_io;

client_obd_list_lock(&cli->cl_lru_list_lock);
- atomic_inc(&cli->cl_lru_shrinkers);
maxscan = min(target << 1, atomic_read(&cli->cl_lru_in_list));
list_for_each_entry_safe(opg, temp, &cli->cl_lru_list, ops_lru) {
struct cl_page *page;
+ bool will_free = false;

if (--maxscan < 0)
break;
@@ -603,7 +672,7 @@ int osc_lru_shrink(struct client_obd *cli, int target)
client_obd_list_unlock(&cli->cl_lru_list_lock);

if (clobj) {
- count -= discard_pagevec(env, io, pvec, index);
+ discard_pagevec(env, io, pvec, index);
index = 0;

cl_io_fini(env, io);
@@ -625,98 +694,56 @@ int osc_lru_shrink(struct client_obd *cli, int target)
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().
- */
- list_move_tail(&opg->ops_lru, &cli->cl_lru_list);
+ if (cl_page_own_try(env, io, page) == 0) {
+ if (!cl_page_in_use_noref(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);
+ }
+ }

- /* 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 (!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);
- count -= discard_pagevec(env, io, pvec, index);
+ 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) {
- count -= discard_pagevec(env, io, pvec, index);
+ discard_pagevec(env, io, pvec, index);

cl_io_fini(env, io);
cl_object_put(env, clobj);
}
cl_env_nested_put(&nest, env);

+out:
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;
-
- atomic_dec(&cli->cl_lru_busy);
- client_obd_list_lock(&cli->cl_lru_list_lock);
- if (list_empty(&opg->ops_lru)) {
- list_move_tail(&opg->ops_lru, &cli->cl_lru_list);
- atomic_inc_return(&cli->cl_lru_in_list);
- wakeup = 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));
+ if (count > 0) {
+ atomic_add(count, cli->cl_lru_left);
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 (!list_empty(&opg->ops_lru)) {
- LASSERT(atomic_read(&cli->cl_lru_in_list) > 0);
- list_del_init(&opg->ops_lru);
- atomic_dec(&cli->cl_lru_in_list);
- if (!del)
- atomic_inc(&cli->cl_lru_busy);
- } else if (del) {
- LASSERT(atomic_read(&cli->cl_lru_busy) > 0);
- atomic_dec(&cli->cl_lru_busy);
- }
- client_obd_list_unlock(&cli->cl_lru_list_lock);
- if (del) {
- 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 (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(list_empty(&opg->ops_lru));
- }
+ return count > 0 ? count : rc;
}

static inline int max_to_shrink(struct client_obd *cli)
@@ -724,16 +751,19 @@ static inline int max_to_shrink(struct client_obd *cli)
return min(atomic_read(&cli->cl_lru_in_list) >> 1, lru_shrink_max);
}

-static int osc_lru_reclaim(struct client_obd *cli)
+int osc_lru_reclaim(struct client_obd *cli)
{
struct cl_client_cache *cache = cli->cl_cache;
int max_scans;
- int rc;
+ int rc = 0;

LASSERT(cache);

- rc = osc_lru_shrink(cli, lru_shrink_min);
+ rc = osc_lru_shrink(cli, lru_shrink_min, 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);
return rc;
@@ -764,10 +794,10 @@ static int osc_lru_reclaim(struct client_obd *cli)
atomic_read(&cli->cl_lru_busy));

list_move_tail(&cli->cl_lru_osc, &cache->ccc_lru);
- if (atomic_read(&cli->cl_lru_in_list) > 0) {
+ if (osc_cache_too_much(cli) > 0) {
spin_unlock(&cache->ccc_lru_lock);

- rc = osc_lru_shrink(cli, max_to_shrink(cli));
+ rc = osc_lru_shrink(cli, osc_cache_too_much(cli), true);
spin_lock(&cache->ccc_lru_lock);
if (rc != 0)
break;
@@ -784,15 +814,20 @@ 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 osc_io *oio = osc_env_io(env);
struct client_obd *cli = osc_cli(obj);
int rc = 0;

if (!cli->cl_cache) /* 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)) {
- int gen;

/* run out of LRU spaces, try to drop some by itself */
rc = osc_lru_reclaim(cli);
@@ -803,23 +838,15 @@ static int osc_lru_reserve(const struct lu_env *env, struct osc_object *obj,

cond_resched();

- /* slowest case, all of caching pages are busy, notifying
- * other OSCs that we're lack of LRU slots.
- */
- atomic_inc(&osc_lru_waiters);
-
- gen = atomic_read(&cli->cl_lru_in_list);
rc = l_wait_event(osc_lru_waitq,
- atomic_read(cli->cl_lru_left) > 0 ||
- (atomic_read(&cli->cl_lru_in_list) > 0 &&
- gen != atomic_read(&cli->cl_lru_in_list)),
+ atomic_read(cli->cl_lru_left) > 0,
&lwi);

- atomic_dec(&osc_lru_waiters);
if (rc < 0)
break;
}

+out:
if (rc >= 0) {
atomic_inc(&cli->cl_lru_busy);
opg->ops_in_lru = 1;
diff --git a/drivers/staging/lustre/lustre/osc/osc_request.c b/drivers/staging/lustre/lustre/osc/osc_request.c
index 850d5dd..6dadda4 100644
--- a/drivers/staging/lustre/lustre/osc/osc_request.c
+++ b/drivers/staging/lustre/lustre/osc/osc_request.c
@@ -2910,7 +2910,7 @@ static int osc_set_info_async(const struct lu_env *env, struct obd_export *exp,
int nr = atomic_read(&cli->cl_lru_in_list) >> 1;
int target = *(int *)val;

- nr = osc_lru_shrink(cli, min(nr, target));
+ nr = osc_lru_shrink(cli, min(nr, target), true);
*(int *)val -= nr;
return 0;
}
--
2.1.0