From 89f342af660332656bbade4cc8a919a40674ac41 Mon Sep 17 00:00:00 2001 From: Shakeel Butt Date: Thu, 3 Apr 2025 18:39:07 -0700 Subject: [PATCH] memcg: introduce memcg_uncharge At multiple places in memcontrol.c, the memory and memsw page counters are being uncharged. This is error-prone. Let's move the functionality to a newly introduced memcg_uncharge and call it from all those places. Link: https://lkml.kernel.org/r/20250404013913.1663035-4-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt Acked-by: Vlastimil Babka Reviewed-by: Roman Gushchin Cc: Johannes Weiner Cc: Michal Hocko Cc: Muchun Song Cc: Sebastian Andrzej Siewior Signed-off-by: Andrew Morton --- mm/memcontrol.c | 28 ++++++++++++---------------- 1 file changed, 12 insertions(+), 16 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 52be78515d70..dfb3f14c1178 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1822,6 +1822,13 @@ static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages, return ret; } +static void memcg_uncharge(struct mem_cgroup *memcg, unsigned int nr_pages) +{ + page_counter_uncharge(&memcg->memory, nr_pages); + if (do_memsw_account()) + page_counter_uncharge(&memcg->memsw, nr_pages); +} + /* * Returns stocks cached in percpu and reset cached information. */ @@ -1834,10 +1841,7 @@ static void drain_stock(struct memcg_stock_pcp *stock) return; if (stock_pages) { - page_counter_uncharge(&old->memory, stock_pages); - if (do_memsw_account()) - page_counter_uncharge(&old->memsw, stock_pages); - + memcg_uncharge(old, stock_pages); WRITE_ONCE(stock->nr_pages, 0); } @@ -1900,9 +1904,7 @@ static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) * In case of unlikely failure to lock percpu stock_lock * uncharge memcg directly. */ - page_counter_uncharge(&memcg->memory, nr_pages); - if (do_memsw_account()) - page_counter_uncharge(&memcg->memsw, nr_pages); + memcg_uncharge(memcg, nr_pages); return; } __refill_stock(memcg, nr_pages); @@ -2876,12 +2878,8 @@ static struct obj_cgroup *drain_obj_stock(struct memcg_stock_pcp *stock) mod_memcg_state(memcg, MEMCG_KMEM, -nr_pages); memcg1_account_kmem(memcg, -nr_pages); - if (!mem_cgroup_is_root(memcg)) { - page_counter_uncharge(&memcg->memory, nr_pages); - if (do_memsw_account()) - page_counter_uncharge(&memcg->memsw, - nr_pages); - } + if (!mem_cgroup_is_root(memcg)) + memcg_uncharge(memcg, nr_pages); css_put(&memcg->css); } @@ -4702,9 +4700,7 @@ static inline void uncharge_gather_clear(struct uncharge_gather *ug) static void uncharge_batch(const struct uncharge_gather *ug) { if (ug->nr_memory) { - page_counter_uncharge(&ug->memcg->memory, ug->nr_memory); - if (do_memsw_account()) - page_counter_uncharge(&ug->memcg->memsw, ug->nr_memory); + memcg_uncharge(ug->memcg, ug->nr_memory); if (ug->nr_kmem) { mod_memcg_state(ug->memcg, MEMCG_KMEM, -ug->nr_kmem); memcg1_account_kmem(ug->memcg, -ug->nr_kmem); -- 2.50.1