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authorWaiman Long <[email protected]>2020-10-13 16:52:52 -0700
committerLinus Torvalds <[email protected]>2020-10-13 18:38:30 -0700
commit8d387a5f172f26ff8c76096d5876b881dec6b7ce (patch)
treedc9826a812183e50957132e408e270c466f5b0f0
parentf9f84ec56f7e370cc6fc478b7d09fbf41de970ea (diff)
mm/memcg: simplify mem_cgroup_get_max()
mem_cgroup_get_max() used to get memory+swap max from both the v1 memsw and v2 memory+swap page counters & return the maximum of these 2 values. This is redundant and it is more efficient to just get either the v1 or the v2 values depending on which one is currently in use. [[email protected]: v4] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Waiman Long <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Reviewed-by: Shakeel Butt <[email protected]> Acked-by: Michal Hocko <[email protected]> Cc: Chris Down <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Tejun Heo <[email protected]> Cc: Vladimir Davydov <[email protected]> Cc: Yafang Shao <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>
-rw-r--r--mm/memcontrol.c24
1 files changed, 13 insertions, 11 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 09e851f0bee3..962f8d649b83 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1633,17 +1633,19 @@ void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg)
*/
unsigned long mem_cgroup_get_max(struct mem_cgroup *memcg)
{
- unsigned long max;
-
- max = READ_ONCE(memcg->memory.max);
- if (mem_cgroup_swappiness(memcg)) {
- unsigned long memsw_max;
- unsigned long swap_max;
-
- memsw_max = memcg->memsw.max;
- swap_max = READ_ONCE(memcg->swap.max);
- swap_max = min(swap_max, (unsigned long)total_swap_pages);
- max = min(max + swap_max, memsw_max);
+ unsigned long max = READ_ONCE(memcg->memory.max);
+
+ if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) {
+ if (mem_cgroup_swappiness(memcg))
+ max += min(READ_ONCE(memcg->swap.max),
+ (unsigned long)total_swap_pages);
+ } else { /* v1 */
+ if (mem_cgroup_swappiness(memcg)) {
+ /* Calculate swap excess capacity from memsw limit */
+ unsigned long swap = READ_ONCE(memcg->memsw.max) - max;
+
+ max += min(swap, (unsigned long)total_swap_pages);
+ }
}
return max;
}