[01/78] mm/memcg: bail early from swap accounting if memcg disabled

Commit Message

Andrew Morton Dec. 18, 2020, 10:01 p.m. UTC

From: Alex Shi <[e-mail]>
Subject: mm/memcg: bail early from swap accounting if memcg disabled

Patch series "bail out early for memcg disable".

These 2 patches are indepenedent from per memcg lru lock, and may
encounter unexpected warning, so let's move out them from per memcg
lru locking patchset.


This patch (of 2):

We could bail out early when memcg wasn't enabled.

Link: https://lkml.kernel.org/r/[e-mail]
Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Alex Shi <[e-mail]>
Reviewed-by: Roman Gushchin <[e-mail]>
Acked-by: Michal Hocko <[e-mail]>
Acked-by: Hugh Dickins <[e-mail]>
Acked-by: Johannes Weiner <[e-mail]>
Cc: Vladimir Davydov <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 mm/memcontrol.c |    6 ++++++
 1 file changed, 6 insertions(+)

Patch

--- a/mm/memcontrol.c~mm-memcg-bail-early-from-swap-accounting-if-memcg-disabled
+++ a/mm/memcontrol.c
@@ -7178,6 +7178,9 @@  void mem_cgroup_swapout(struct page *pag
 	VM_BUG_ON_PAGE(PageLRU(page), page);
 	VM_BUG_ON_PAGE(page_count(page), page);
 
+	if (mem_cgroup_disabled())
+		return;
+
 	if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
 		return;
 
@@ -7242,6 +7245,9 @@  int mem_cgroup_try_charge_swap(struct pa
 	struct mem_cgroup *memcg;
 	unsigned short oldid;
 
+	if (mem_cgroup_disabled())
+		return 0;
+
 	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
 		return 0;