The patch titled
Subject: mm, memcontrol: avoid duplicated memcg enable check
has been added to the -mm mm-unstable branch. Its filename is
mm-memcontrol-avoid-duplicated-memcg-enable-check.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-memcontrol-avoid-duplicated-memcg-enable-check.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Kairui Song <kasong@xxxxxxxxxxx>
Subject: mm, memcontrol: avoid duplicated memcg enable check
Date: Tue, 10 Dec 2024 17:28:03 +0800
Patch series "mm/swap_cgroup: remove global swap cgroup lock", v2.
This series removes the global swap cgroup lock. The critical section of
this lock is very short but it's still a bottle neck for mass parallel
swap workloads.
Up to 10% performance gain for tmpfs build kernel test on a 48c96t system,
and no regression for other cases:
Testing using 64G brd and build with build kernel with make -j96 in 1.5G
memory cgroup using 4k folios showed below improvement (10 test run):
Before this series:
Sys time: 10809.46 (stdev 80.831491)
Real time: 171.41 (stdev 1.239894)
After this commit:
Sys time: 9621.26 (stdev 34.620000), -10.42%
Real time: 160.00 (stdev 0.497814), -6.57%
With 64k folios and 2G memcg:
Before this series:
Sys time: 8231.99 (stdev 30.030994)
Real time: 143.57 (stdev 0.577394)
After this commit:
Sys time: 7403.47 (stdev 6.270000), -10.06%
Real time: 135.18 (stdev 0.605000), -5.84%
Sequential swapout of 8G 64k zero folios (24 test run):
Before this series:
5461409.12 us (stdev 183957.827084)
After this commit:
5420447.26 us (stdev 196419.240317)
Sequential swapin of 8G 4k zero folios (24 test run):
Before this series:
19736958.916667 us (stdev 189027.246676)
After this commit:
19662182.629630 us (stdev 172717.640614)
This patch (of 3):
mem_cgroup_uncharge_swap() includes a mem_cgroup_disabled() check, so the
caller doesn't need to check that.
Link: https://lkml.kernel.org/r/20241210092805.87281-1-ryncsn@xxxxxxxxx
Link: https://lkml.kernel.org/r/20241210092805.87281-2-ryncsn@xxxxxxxxx
Signed-off-by: Kairui Song <kasong@xxxxxxxxxxx>
Reviewed-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Reviewed-by: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Acked-by: Shakeel Butt <shakeel.butt@xxxxxxxxx>
Acked-by: Chris Li <chrisl@xxxxxxxxxx>
Cc: Barry Song <baohua@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/memcontrol.c~mm-memcontrol-avoid-duplicated-memcg-enable-check
+++ a/mm/memcontrol.c
@@ -4609,7 +4609,7 @@ void mem_cgroup_swapin_uncharge_swap(swp
* correspond 1:1 to page and swap slot lifetimes: we charge the
* page to memory here, and uncharge swap when the slot is freed.
*/
- if (!mem_cgroup_disabled() && do_memsw_account()) {
+ if (do_memsw_account()) {
/*
* The swap entry might not get freed for a long time,
* let's not wait for it. The page already received a
_
Patches currently in -mm which might be from kasong@xxxxxxxxxxx are
zram-refuse-to-use-zero-sized-block-device-as-backing-device.patch
zram-fix-uninitialized-zram-not-releasing-backing-device.patch
mm-memcontrol-avoid-duplicated-memcg-enable-check.patch
mm-swap_cgroup-remove-swap_cgroup_cmpxchg.patch
mm-swap_cgroup-remove-global-swap-cgroup-lock.patch
