mm/memcontrol.c:mem_cgroup_select_victim_node(): clarify comment

> The comment seems to have not much to do with the code?

I guess the comment tries to say that the code path is triggered when we
charge the page which happens _before_ it is added to the LRU list and
so last_scanned_node might contain the stale data.

Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Michal Hocko 2016-05-19 17:11:34 -07:00 committed by Linus Torvalds
parent 4ee815be1d
commit fda3d69be9
1 changed files with 3 additions and 4 deletions

View File

@ -1391,10 +1391,9 @@ int mem_cgroup_select_victim_node(struct mem_cgroup *memcg)
node = next_node_in(node, memcg->scan_nodes);
/*
* We call this when we hit limit, not when pages are added to LRU.
* No LRU may hold pages because all pages are UNEVICTABLE or
* memcg is too small and all pages are not on LRU. In that case,
* we use curret node.
* mem_cgroup_may_update_nodemask might have seen no reclaimmable pages
* last time it really checked all the LRUs due to rate limiting.
* Fallback to the current node in that case for simplicity.
*/
if (unlikely(node == MAX_NUMNODES))
node = numa_node_id();