#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);
{
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]);
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,
}
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,
*/
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
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;
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;
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);
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)
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;
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;
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);
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;
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