The mem_cgroup_get_max() function 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.
Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
---
mm/memcontrol.c | 24 +++++++++++++-----------
1 file changed, 13 insertions(+), 11 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 8c74f1200261..cad1ac4551ad 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;
}
--
2.18.1
