[Devel] [PATCH rh7 2/2] mm/vmscan: add cond_resched() to loop in shrink_slab_memcg()

[Andrey Ryabinin]

shrink_slab_memcg() may iterate for a long time without resched if we
have many memcg with small amount of objects. Add cond_resched() to
avoid potential softlockup.

https://jira.sw.ru/browse/PSBM-125095
Signed-off-by: Andrey Ryabinin <aryabinin at virtuozzo.com>
---
 mm/vmscan.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 080500f4e366..17a7ed60f525 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -527,6 +527,8 @@ static unsigned long shrink_slab_memcg(gfp_t gfp_mask, int nid,
 		struct shrinker *shrinker;
 		bool is_nfs;
 
+		cond_resched();
+
 		shrinker = idr_find(&shrinker_idr, i);
 		if (unlikely(!shrinker)) {
 			clear_bit(i, map->map);
-- 
2.26.2