From: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Subject: mm, memcg: add mem_cgroup_disabled checks in vmpressure and swap-related functions
Add mem_cgroup_disabled check in vmpressure, mem_cgroup_uncharge_swap and
cgroup_throttle_swaprate functions. This minimizes the memcg overhead in
the pagefault and exit_mmap paths when memcgs are disabled using
cgroup_disable=memory command-line option.
This change results in ~2.1% overhead reduction when running PFT test [1]
comparing {CONFIG_MEMCG=n, CONFIG_MEMCG_SWAP=n} against {CONFIG_MEMCG=y,
CONFIG_MEMCG_SWAP=y, cgroup_disable=memory} configuration on an 8-core
ARM64 Android device.
[1] https://lkml.org/lkml/2006/8/29/294 also used in mmtests suite
Link: https://lkml.kernel.org/r/20210713010934.299876-1-surenb@xxxxxxxxxx
Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Cc: Alex Shi <alexs@xxxxxxxxxx>
Cc: Alistair Popple <apopple@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Roman Gushchin <guro@xxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Wei Yang <richard.weiyang@xxxxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 3 +++
mm/swapfile.c | 3 +++
mm/vmpressure.c | 7 ++++++-
3 files changed, 12 insertions(+), 1 deletion(-)
--- a/mm/memcontrol.c~mm-memcg-add-mem_cgroup_disabled-checks-in-vmpressure-and-swap-related-functions
+++ a/mm/memcontrol.c
@@ -7297,6 +7297,9 @@ void mem_cgroup_uncharge_swap(swp_entry_
struct mem_cgroup *memcg;
unsigned short id;
+ if (mem_cgroup_disabled())
+ return;
+
id = swap_cgroup_record(entry, 0, nr_pages);
rcu_read_lock();
memcg = mem_cgroup_from_id(id);
--- a/mm/swapfile.c~mm-memcg-add-mem_cgroup_disabled-checks-in-vmpressure-and-swap-related-functions
+++ a/mm/swapfile.c
@@ -3784,6 +3784,9 @@ void cgroup_throttle_swaprate(struct pag
struct swap_info_struct *si, *next;
int nid = page_to_nid(page);
+ if (mem_cgroup_disabled())
+ return;
+
if (!(gfp_mask & __GFP_IO))
return;
--- a/mm/vmpressure.c~mm-memcg-add-mem_cgroup_disabled-checks-in-vmpressure-and-swap-related-functions
+++ a/mm/vmpressure.c
@@ -240,7 +240,12 @@ static void vmpressure_work_fn(struct wo
void vmpressure(gfp_t gfp, struct mem_cgroup *memcg, bool tree,
unsigned long scanned, unsigned long reclaimed)
{
- struct vmpressure *vmpr = memcg_to_vmpressure(memcg);
+ struct vmpressure *vmpr;
+
+ if (mem_cgroup_disabled())
+ return;
+
+ vmpr = memcg_to_vmpressure(memcg);
/*
* Here we only want to account pressure that userland is able to
_
