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mm: memcontrol: drain memcg stock on force_empty

PATCH In review Shakeel Butt 2 participants 3 messages May 7, 2018 – May 9, 2018

Subsystems (3)
Memory management cgroup memcg
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Shakeel Butt

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#0 lore raw

PATCH 1/1 mm: memcontrol: drain memcg stock on force_empty

From: Junaid Shahid <[email protected]>

The per-cpu memcg stock can retain a charge of upto 32 pages. On a machine with large number of cpus, this can amount to a decent amount of memory. Additionally force_empty interface might be triggering unneeded memcg reclaims.

Signed-off-by Junaid Shahid <[email protected]>
Signed-off-by Shakeel Butt <[email protected]>
---
 mm/memcontrol.c | 3 +++
 1 file changed, 3 insertions(+)
mm/memcontrol.c +3 -0
index e2d33a37f971..2c3c69524b49 100644
@@ -2841,6 +2841,9 @@ static int mem_cgroup_force_empty(struct mem_cgroup *memcg)
 
 	/* we call try-to-free pages for make this cgroup empty */
 	lru_add_drain_all();
+
+	drain_all_stock(memcg);
+
 	/* try to free all pages in this cgroup */
 	while (nr_retries && page_counter_read(&memcg->memory)) {
 		int progress;
Signature · 1 line
2.17.0.441.gb46fe60e1d-goog
author
#1 lore raw
Quoted 8 lines · Shakeel Butt

From: Junaid Shahid <[email protected]>

The per-cpu memcg stock can retain a charge of upto 32 pages. On a machine with large number of cpus, this can amount to a decent amount of memory. Additionally force_empty interface might be triggering unneeded memcg reclaims.

Signed-off-by Junaid Shahid <[email protected]>

This should be "Junaid Shahid <[email protected]>".

mm/memcontrol.c static int mem_cgroup_force_empty(struct mem_cgroup

Quoted 10 lines
Signed-off-by Shakeel Butt <[email protected]>
---
  mm/memcontrol.c | 3 +++
  1 file changed, 3 insertions(+)
mm/memcontrol.c +0 -0
index e2d33a37f971..2c3c69524b49 100644
@@ -2841,6 +2841,9 @@ static int mem_cgroup_force_empty(struct mem_cgroup

*memcg)

Quoted 10 lines
mm/memcontrol.c +3 -1
         /* we call try-to-free pages for make this cgroup empty */
         lru_add_drain_all();
+
+       drain_all_stock(memcg);
+
         /* try to free all pages in this cgroup */
         while (nr_retries && page_counter_read(&memcg->memory)) {
                 int progress;
--

2.17.0.441.gb46fe60e1d-goog

maintainer Acked-by on v1 1/1
#2 lore raw
In reply to Shakeel Butt
Quoted 9 lines · Shakeel Butt

From: Junaid Shahid <[email protected]>

The per-cpu memcg stock can retain a charge of upto 32 pages. On a machine with large number of cpus, this can amount to a decent amount of memory. Additionally force_empty interface might be triggering unneeded memcg reclaims.

Signed-off-by Junaid Shahid <[email protected]>
Signed-off-by Shakeel Butt <[email protected]>
Acked-by Michal Hocko <[email protected]>
Quoted 20 lines
---
 mm/memcontrol.c | 3 +++
 1 file changed, 3 insertions(+)
mm/memcontrol.c +3 -0
index e2d33a37f971..2c3c69524b49 100644
@@ -2841,6 +2841,9 @@ static int mem_cgroup_force_empty(struct mem_cgroup *memcg)
 
 	/* we call try-to-free pages for make this cgroup empty */
 	lru_add_drain_all();
+
+	drain_all_stock(memcg);
+
 	/* try to free all pages in this cgroup */
 	while (nr_retries && page_counter_read(&memcg->memory)) {
 		int progress;
Signature · 1 line
2.17.0.441.gb46fe60e1d-goog
Signature · 2 lines
Michal Hocko
SUSE Labs