Check shrinker enablement early, and use a less costly stat flushing.
Suggested-by: Yosry Ahmed yosryahmed@google.com Suggested-by: Chengming Zhou chengming.zhou@linux.dev Signed-off-by: Nhat Pham nphamcs@gmail.com --- mm/zswap.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/mm/zswap.c b/mm/zswap.c index 27c749f6c1ba..d8ecd79120f3 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -596,13 +596,17 @@ static unsigned long zswap_shrinker_scan(struct shrinker *shrinker, struct zswap_pool *pool = shrinker->private_data; bool encountered_page_in_swapcache = false;
+ if (!zswap_shrinker_enabled) { + sc->nr_scanned = 0; + return SHRINK_STOP; + } + nr_protected = atomic_long_read(&lruvec->zswap_lruvec_state.nr_zswap_protected); lru_size = list_lru_shrink_count(&pool->list_lru, sc);
/* - * Abort if the shrinker is disabled or if we are shrinking into the - * protected region. + * Abort if we are shrinking into the protected region. * * This short-circuiting is necessary because if we have too many multiple * concurrent reclaimers getting the freeable zswap object counts at the @@ -611,7 +615,7 @@ static unsigned long zswap_shrinker_scan(struct shrinker *shrinker, * objects (i.e the reclaimers will reclaim into the protected area of the * zswap LRU). */ - if (!zswap_shrinker_enabled || nr_protected >= lru_size - sc->nr_to_scan) { + if (nr_protected >= lru_size - sc->nr_to_scan) { sc->nr_scanned = 0; return SHRINK_STOP; } @@ -633,8 +637,11 @@ static unsigned long zswap_shrinker_count(struct shrinker *shrinker, struct lruvec *lruvec = mem_cgroup_lruvec(memcg, NODE_DATA(sc->nid)); unsigned long nr_backing, nr_stored, nr_freeable, nr_protected;
+ if (!zswap_shrinker_enabled) + return 0; + #ifdef CONFIG_MEMCG_KMEM - cgroup_rstat_flush(memcg->css.cgroup); + mem_cgroup_flush_stats(); nr_backing = memcg_page_state(memcg, MEMCG_ZSWAP_B) >> PAGE_SHIFT; nr_stored = memcg_page_state(memcg, MEMCG_ZSWAPPED); #else @@ -643,7 +650,7 @@ static unsigned long zswap_shrinker_count(struct shrinker *shrinker, nr_stored = atomic_read(&pool->nr_stored); #endif
- if (!zswap_shrinker_enabled || !nr_stored) + if (!nr_stored) return 0;
nr_protected =