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| author | Shakeel Butt <shakeel.butt@linux.dev> | 2025-04-03 18:39:09 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-05-11 17:48:11 -0700 |
| commit | b6d0471117daec360bad2b881c1e2d0f4d2c4d3b (patch) | |
| tree | fd44261b293a3449b5165093ffc9c1d2aff67988 /mm/memcontrol.c | |
| parent | cbc091441d3adce9a1fbcd0a0a84bd6abe077a5b (diff) | |
| download | linux-b6d0471117daec360bad2b881c1e2d0f4d2c4d3b.tar.gz linux-b6d0471117daec360bad2b881c1e2d0f4d2c4d3b.tar.bz2 linux-b6d0471117daec360bad2b881c1e2d0f4d2c4d3b.zip | |
memcg: no refilling stock from obj_cgroup_release
obj_cgroup_release is called when all the references to the objcg have
been released i.e. no more memory objects are pointing to it. Most
probably objcg->memcg will be pointing to some ancestor memcg. In
obj_cgroup_release(), the kernel calls obj_cgroup_uncharge_pages() which
refills the local stock.
There is no need to refill the local stock with some ancestor memcg and
flush the local stock. Let's decouple obj_cgroup_release() from the local
stock by uncharging instead of refilling. One additional benefit of this
change is that it removes the requirement to only call obj_cgroup_put()
outside of local_lock.
Link: https://lkml.kernel.org/r/20250404013913.1663035-6-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/memcontrol.c')
| -rw-r--r-- | mm/memcontrol.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 03a2be6d4a67..df52084e90f4 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -129,8 +129,7 @@ bool mem_cgroup_kmem_disabled(void) return cgroup_memory_nokmem; } -static void obj_cgroup_uncharge_pages(struct obj_cgroup *objcg, - unsigned int nr_pages); +static void memcg_uncharge(struct mem_cgroup *memcg, unsigned int nr_pages); static void obj_cgroup_release(struct percpu_ref *ref) { @@ -163,8 +162,16 @@ static void obj_cgroup_release(struct percpu_ref *ref) WARN_ON_ONCE(nr_bytes & (PAGE_SIZE - 1)); nr_pages = nr_bytes >> PAGE_SHIFT; - if (nr_pages) - obj_cgroup_uncharge_pages(objcg, nr_pages); + if (nr_pages) { + struct mem_cgroup *memcg; + + memcg = get_mem_cgroup_from_objcg(objcg); + mod_memcg_state(memcg, MEMCG_KMEM, -nr_pages); + memcg1_account_kmem(memcg, -nr_pages); + if (!mem_cgroup_is_root(memcg)) + memcg_uncharge(memcg, nr_pages); + mem_cgroup_put(memcg); + } spin_lock_irqsave(&objcg_lock, flags); list_del(&objcg->list); |