mm: memcontrol: drain stocks on resize limit

Resizing the memcg limit for cgroup-v2 drains the stocks before
triggering the memcg reclaim.  Do the same for cgroup-v1 to make the
behavior consistent.

Link: http://lkml.kernel.org/r/20180504205548.110696-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 847a775af225ca6d7e1f8066f32a237f39274450..18dcdac0b158b09e84c1eada2facc96a9951e62a 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2450,6 +2450,7 @@ static int mem_cgroup_resize_max(struct mem_cgroup *memcg,
                                 unsigned long max, bool memsw)
 {
        bool enlarge = false;
+       bool drained = false;
        int ret;
        bool limits_invariant;
        struct page_counter *counter = memsw ? &memcg->memsw : &memcg->memory;
@@ -2480,6 +2481,12 @@ static int mem_cgroup_resize_max(struct mem_cgroup *memcg,
                if (!ret)
                        break;
 
+               if (!drained) {
+                       drain_all_stock(memcg);
+                       drained = true;
+                       continue;
+               }
+
                if (!try_to_free_mem_cgroup_pages(memcg, 1,
                                        GFP_KERNEL, !memsw)) {
                        ret = -EBUSY;