diff options
| -rw-r--r-- | include/linux/shrinker.h | 1 | ||||
| -rw-r--r-- | mm/vmscan.c | 15 |
2 files changed, 16 insertions, 0 deletions
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h index 9814fff58a69..76fbf92b04d9 100644 --- a/include/linux/shrinker.h +++ b/include/linux/shrinker.h @@ -93,4 +93,5 @@ extern void register_shrinker_prepared(struct shrinker *shrinker); extern int register_shrinker(struct shrinker *shrinker); extern void unregister_shrinker(struct shrinker *shrinker); extern void free_prealloced_shrinker(struct shrinker *shrinker); +extern void synchronize_shrinkers(void); #endif diff --git a/mm/vmscan.c b/mm/vmscan.c index 4620df62f0ff..5d22a63472f0 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -638,6 +638,21 @@ void unregister_shrinker(struct shrinker *shrinker) } EXPORT_SYMBOL(unregister_shrinker); +/** + * synchronize_shrinkers - Wait for all running shrinkers to complete. + * + * This is equivalent to calling unregister_shrink() and register_shrinker(), + * but atomically and with less overhead. This is useful to guarantee that all + * shrinker invocations have seen an update, before freeing memory, similar to + * rcu. + */ +void synchronize_shrinkers(void) +{ + down_write(&shrinker_rwsem); + up_write(&shrinker_rwsem); +} +EXPORT_SYMBOL(synchronize_shrinkers); + #define SHRINK_BATCH 128 static unsigned long do_shrink_slab(struct shrink_control *shrinkctl, |