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-rw-r--r--drivers/staging/lustre/lustre/include/lu_object.h6
-rw-r--r--drivers/staging/lustre/lustre/obdclass/lu_object.c80
2 files changed, 43 insertions, 43 deletions
diff --git a/drivers/staging/lustre/lustre/include/lu_object.h b/drivers/staging/lustre/lustre/include/lu_object.h
index f283a036a748..0826c1956ba8 100644
--- a/drivers/staging/lustre/lustre/include/lu_object.h
+++ b/drivers/staging/lustre/lustre/include/lu_object.h
@@ -34,6 +34,7 @@
#define __LUSTRE_LU_OBJECT_H
#include <stdarg.h>
+#include <linux/percpu_counter.h>
#include "../../include/linux/libcfs/libcfs.h"
#include "lustre/lustre_idl.h"
#include "lu_ref.h"
@@ -580,7 +581,6 @@ enum {
LU_SS_CACHE_RACE,
LU_SS_CACHE_DEATH_RACE,
LU_SS_LRU_PURGED,
- LU_SS_LRU_LEN, /* # of objects in lsb_lru lists */
LU_SS_LAST_STAT
};
@@ -635,6 +635,10 @@ struct lu_site {
* XXX: a hack! fld has to find md_site via site, remove when possible
*/
struct seq_server_site *ld_seq_site;
+ /**
+ * Number of objects in lsb_lru_lists - used for shrinking
+ */
+ struct percpu_counter ls_lru_len_counter;
};
static inline struct lu_site_bkt_data *
diff --git a/drivers/staging/lustre/lustre/obdclass/lu_object.c b/drivers/staging/lustre/lustre/obdclass/lu_object.c
index 7971562a3efd..18058615bd96 100644
--- a/drivers/staging/lustre/lustre/obdclass/lu_object.c
+++ b/drivers/staging/lustre/lustre/obdclass/lu_object.c
@@ -151,7 +151,7 @@ void lu_object_put(const struct lu_env *env, struct lu_object *o)
LASSERT(list_empty(&top->loh_lru));
list_add_tail(&top->loh_lru, &bkt->lsb_lru);
bkt->lsb_lru_len++;
- lprocfs_counter_incr(site->ls_stats, LU_SS_LRU_LEN);
+ percpu_counter_inc(&site->ls_lru_len_counter);
CDEBUG(D_INODE, "Add %p to site lru. hash: %p, bkt: %p, lru_len: %ld\n",
o, site->ls_obj_hash, bkt, bkt->lsb_lru_len);
cfs_hash_bd_unlock(site->ls_obj_hash, &bd, 1);
@@ -202,7 +202,7 @@ void lu_object_unhash(const struct lu_env *env, struct lu_object *o)
list_del_init(&top->loh_lru);
bkt = cfs_hash_bd_extra_get(obj_hash, &bd);
bkt->lsb_lru_len--;
- lprocfs_counter_decr(site->ls_stats, LU_SS_LRU_LEN);
+ percpu_counter_dec(&site->ls_lru_len_counter);
}
cfs_hash_bd_del_locked(obj_hash, &bd, &top->loh_hash);
cfs_hash_bd_unlock(obj_hash, &bd, 1);
@@ -379,7 +379,7 @@ int lu_site_purge(const struct lu_env *env, struct lu_site *s, int nr)
&bd2, &h->loh_hash);
list_move(&h->loh_lru, &dispose);
bkt->lsb_lru_len--;
- lprocfs_counter_decr(s->ls_stats, LU_SS_LRU_LEN);
+ percpu_counter_dec(&s->ls_lru_len_counter);
if (did_sth == 0)
did_sth = 1;
@@ -578,7 +578,7 @@ static struct lu_object *htable_lookup(struct lu_site *s,
if (!list_empty(&h->loh_lru)) {
list_del_init(&h->loh_lru);
bkt->lsb_lru_len--;
- lprocfs_counter_decr(s->ls_stats, LU_SS_LRU_LEN);
+ percpu_counter_dec(&s->ls_lru_len_counter);
}
return lu_object_top(h);
}
@@ -820,7 +820,7 @@ EXPORT_SYMBOL(lu_device_type_fini);
* Global list of all sites on this node
*/
static LIST_HEAD(lu_sites);
-static DEFINE_MUTEX(lu_sites_guard);
+static DECLARE_RWSEM(lu_sites_guard);
/**
* Global environment used by site shrinker.
@@ -994,9 +994,15 @@ int lu_site_init(struct lu_site *s, struct lu_device *top)
unsigned long bits;
unsigned long i;
char name[16];
+ int rc;
memset(s, 0, sizeof(*s));
mutex_init(&s->ls_purge_mutex);
+
+ rc = percpu_counter_init(&s->ls_lru_len_counter, 0, GFP_NOFS);
+ if (rc)
+ return -ENOMEM;
+
snprintf(name, sizeof(name), "lu_site_%s", top->ld_type->ldt_name);
for (bits = lu_htable_order(top); bits >= LU_SITE_BITS_MIN; bits--) {
s->ls_obj_hash = cfs_hash_create(name, bits, bits,
@@ -1042,12 +1048,6 @@ int lu_site_init(struct lu_site *s, struct lu_device *top)
0, "cache_death_race", "cache_death_race");
lprocfs_counter_init(s->ls_stats, LU_SS_LRU_PURGED,
0, "lru_purged", "lru_purged");
- /*
- * Unlike other counters, lru_len can be decremented so
- * need lc_sum instead of just lc_count
- */
- lprocfs_counter_init(s->ls_stats, LU_SS_LRU_LEN,
- LPROCFS_CNTR_AVGMINMAX, "lru_len", "lru_len");
INIT_LIST_HEAD(&s->ls_linkage);
s->ls_top_dev = top;
@@ -1069,9 +1069,11 @@ EXPORT_SYMBOL(lu_site_init);
*/
void lu_site_fini(struct lu_site *s)
{
- mutex_lock(&lu_sites_guard);
+ down_write(&lu_sites_guard);
list_del_init(&s->ls_linkage);
- mutex_unlock(&lu_sites_guard);
+ up_write(&lu_sites_guard);
+
+ percpu_counter_destroy(&s->ls_lru_len_counter);
if (s->ls_obj_hash) {
cfs_hash_putref(s->ls_obj_hash);
@@ -1097,11 +1099,11 @@ int lu_site_init_finish(struct lu_site *s)
{
int result;
- mutex_lock(&lu_sites_guard);
+ down_write(&lu_sites_guard);
result = lu_context_refill(&lu_shrink_env.le_ctx);
if (result == 0)
list_add(&s->ls_linkage, &lu_sites);
- mutex_unlock(&lu_sites_guard);
+ up_write(&lu_sites_guard);
return result;
}
EXPORT_SYMBOL(lu_site_init_finish);
@@ -1820,12 +1822,15 @@ static void lu_site_stats_get(struct cfs_hash *hs,
}
/*
- * lu_cache_shrink_count returns the number of cached objects that are
- * candidates to be freed by shrink_slab(). A counter, which tracks
- * the number of items in the site's lru, is maintained in the per cpu
- * stats of each site. The counter is incremented when an object is added
- * to a site's lru and decremented when one is removed. The number of
- * free-able objects is the sum of all per cpu counters for all sites.
+ * lu_cache_shrink_count() returns an approximate number of cached objects
+ * that can be freed by shrink_slab(). A counter, which tracks the
+ * number of items in the site's lru, is maintained in a percpu_counter
+ * for each site. The percpu values are incremented and decremented as
+ * objects are added or removed from the lru. The percpu values are summed
+ * and saved whenever a percpu value exceeds a threshold. Thus the saved,
+ * summed value at any given time may not accurately reflect the current
+ * lru length. But this value is sufficiently accurate for the needs of
+ * a shrinker.
*
* Using a per cpu counter is a compromise solution to concurrent access:
* lu_object_put() can update the counter without locking the site and
@@ -1842,11 +1847,10 @@ static unsigned long lu_cache_shrink_count(struct shrinker *sk,
if (!(sc->gfp_mask & __GFP_FS))
return 0;
- mutex_lock(&lu_sites_guard);
- list_for_each_entry_safe(s, tmp, &lu_sites, ls_linkage) {
- cached += ls_stats_read(s->ls_stats, LU_SS_LRU_LEN);
- }
- mutex_unlock(&lu_sites_guard);
+ down_read(&lu_sites_guard);
+ list_for_each_entry_safe(s, tmp, &lu_sites, ls_linkage)
+ cached += percpu_counter_read_positive(&s->ls_lru_len_counter);
+ up_read(&lu_sites_guard);
cached = (cached / 100) * sysctl_vfs_cache_pressure;
CDEBUG(D_INODE, "%ld objects cached, cache pressure %d\n",
@@ -1877,7 +1881,7 @@ static unsigned long lu_cache_shrink_scan(struct shrinker *sk,
*/
return SHRINK_STOP;
- mutex_lock(&lu_sites_guard);
+ down_write(&lu_sites_guard);
list_for_each_entry_safe(s, tmp, &lu_sites, ls_linkage) {
freed = lu_site_purge(&lu_shrink_env, s, remain);
remain -= freed;
@@ -1888,7 +1892,7 @@ static unsigned long lu_cache_shrink_scan(struct shrinker *sk,
list_move_tail(&s->ls_linkage, &splice);
}
list_splice(&splice, lu_sites.prev);
- mutex_unlock(&lu_sites_guard);
+ up_write(&lu_sites_guard);
return sc->nr_to_scan - remain;
}
@@ -1925,9 +1929,9 @@ int lu_global_init(void)
* conservatively. This should not be too bad, because this
* environment is global.
*/
- mutex_lock(&lu_sites_guard);
+ down_write(&lu_sites_guard);
result = lu_env_init(&lu_shrink_env, LCT_SHRINKER);
- mutex_unlock(&lu_sites_guard);
+ up_write(&lu_sites_guard);
if (result != 0)
return result;
@@ -1953,9 +1957,9 @@ void lu_global_fini(void)
* Tear shrinker environment down _after_ de-registering
* lu_global_key, because the latter has a value in the former.
*/
- mutex_lock(&lu_sites_guard);
+ down_write(&lu_sites_guard);
lu_env_fini(&lu_shrink_env);
- mutex_unlock(&lu_sites_guard);
+ up_write(&lu_sites_guard);
lu_ref_global_fini();
}
@@ -1965,13 +1969,6 @@ static __u32 ls_stats_read(struct lprocfs_stats *stats, int idx)
struct lprocfs_counter ret;
lprocfs_stats_collect(stats, idx, &ret);
- if (idx == LU_SS_LRU_LEN)
- /*
- * protect against counter on cpu A being decremented
- * before counter is incremented on cpu B; unlikely
- */
- return (__u32)((ret.lc_sum > 0) ? ret.lc_sum : 0);
-
return (__u32)ret.lc_count;
}
@@ -1986,7 +1983,7 @@ int lu_site_stats_print(const struct lu_site *s, struct seq_file *m)
memset(&stats, 0, sizeof(stats));
lu_site_stats_get(s->ls_obj_hash, &stats, 1);
- seq_printf(m, "%d/%d %d/%ld %d %d %d %d %d %d %d %d\n",
+ seq_printf(m, "%d/%d %d/%ld %d %d %d %d %d %d %d\n",
stats.lss_busy,
stats.lss_total,
stats.lss_populated,
@@ -1997,8 +1994,7 @@ int lu_site_stats_print(const struct lu_site *s, struct seq_file *m)
ls_stats_read(s->ls_stats, LU_SS_CACHE_MISS),
ls_stats_read(s->ls_stats, LU_SS_CACHE_RACE),
ls_stats_read(s->ls_stats, LU_SS_CACHE_DEATH_RACE),
- ls_stats_read(s->ls_stats, LU_SS_LRU_PURGED),
- ls_stats_read(s->ls_stats, LU_SS_LRU_LEN));
+ ls_stats_read(s->ls_stats, LU_SS_LRU_PURGED));
return 0;
}
EXPORT_SYMBOL(lu_site_stats_print);
generated by cgit v1.2.3 (git 2.39.0) at 2025-01-12 09:03:04 +0300