Throttle number of freed slabs based on nr_to_scan

[mirror_spl-debian.git] / module / spl / spl-kmem.c

diff --git a/module/spl/spl-kmem.c b/module/spl/spl-kmem.c
index 446dab128f1392a694f4c6d5dfb9a3c318901282..eadf1cb179a442156b99b6a28e997050c01a4c2b 100644 (file)
--- a/module/spl/spl-kmem.c
+++ b/module/spl/spl-kmem.c
@@ -1087,7 +1087,7 @@ spl_slab_reclaim(spl_kmem_cache_t *skc, int count, int flag)
                 * scanning.  Additionally, stop when reaching the target
                 * reclaim 'count' if a non-zero threshold is given.
                 */
-               if ((sks->sks_ref > 0) || (count && i > count))
+               if ((sks->sks_ref > 0) || (count && i >= count))
                        break;
 
                if (time_after(jiffies,sks->sks_age+skc->skc_delay*HZ)||flag) {
@@ -1857,8 +1857,9 @@ EXPORT_SYMBOL(spl_kmem_cache_free);
  * is called.  The shrinker should return the number of free objects
  * in the cache when called with nr_to_scan == 0 but not attempt to
  * free any objects.  When nr_to_scan > 0 it is a request that nr_to_scan
- * objects should be freed, because Solaris semantics are to free
- * all available objects we may free more objects than requested.
+ * objects should be freed, which differs from Solaris semantics.
+ * Solaris semantics are to free all available objects which may (and
+ * probably will) be more objects than the requested nr_to_scan.
  */
 static int
 __spl_kmem_cache_generic_shrinker(struct shrinker *shrink,
@@ -1870,7 +1871,8 @@ __spl_kmem_cache_generic_shrinker(struct shrinker *shrink,
        down_read(&spl_kmem_cache_sem);
        list_for_each_entry(skc, &spl_kmem_cache_list, skc_list) {
                if (sc->nr_to_scan)
-                       spl_kmem_cache_reap_now(skc);
+                       spl_kmem_cache_reap_now(skc,
+                          MAX(sc->nr_to_scan >> fls64(skc->skc_slab_objs), 1));
 
                /*
                 * Presume everything alloc'ed in reclaimable, this ensures
@@ -1896,7 +1898,7 @@ SPL_SHRINKER_CALLBACK_WRAPPER(spl_kmem_cache_generic_shrinker);
  * effort and we do not want to thrash creating and destroying slabs.
  */
 void
-spl_kmem_cache_reap_now(spl_kmem_cache_t *skc)
+spl_kmem_cache_reap_now(spl_kmem_cache_t *skc, int count)
 {
        SENTRY;
 
@@ -1914,7 +1916,7 @@ spl_kmem_cache_reap_now(spl_kmem_cache_t *skc)
        if (skc->skc_reclaim)
                skc->skc_reclaim(skc->skc_private);
 
-       spl_slab_reclaim(skc, skc->skc_reap, 0);
+       spl_slab_reclaim(skc, count, 0);
        clear_bit(KMC_BIT_REAPING, &skc->skc_flags);
        atomic_dec(&skc->skc_ref);