Commit af9a3b69 authored by Johannes Weiner's avatar Johannes Weiner Committed by Linus Torvalds
Browse files

mm/memcg: opencode the inner part of obj_cgroup_uncharge_pages() in drain_obj_stock() 

Provide the inner part of refill_stock() as __refill_stock() without
disabling interrupts.  This eases the integration of local_lock_t where
recursive locking must be avoided.

Open code obj_cgroup_uncharge_pages() in drain_obj_stock() and use
__refill_stock().  The caller of drain_obj_stock() already disables
interrupts.

[bigeasy@linutronix.de: patch body around Johannes' diff]

Link: https://lkml.kernel.org/r/20220226204144.1008339-5-bigeasy@linutronix.de


Signed-off-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: default avatarShakeel Butt <shakeelb@google.com>
Reviewed-by: default avatarRoman Gushchin <guro@fb.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Cc: kernel test robot <oliver.sang@intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent be3e67b5

mm/memcontrol.c

+18 −6
Original line number Diff line number Diff line
@@ -2251,12 +2251,9 @@ static void drain_local_stock(struct work_struct *dummy) 
 * Cache charges(val) to local per_cpu area.

 * This will be consumed by consume_stock() function, later.

 */

static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)

static void __refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)

{

	struct memcg_stock_pcp *stock;

	unsigned long flags;



	local_irq_save(flags);



	stock = this_cpu_ptr(&memcg_stock);

	if (stock->cached != memcg) { /* reset if necessary */
@@ -2268,7 +2265,14 @@ static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) 


	if (stock->nr_pages > MEMCG_CHARGE_BATCH)

		drain_stock(stock);

}



static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)

{

	unsigned long flags;



	local_irq_save(flags);

	__refill_stock(memcg, nr_pages);

	local_irq_restore(flags);

}
@@ -3185,8 +3189,16 @@ static void drain_obj_stock(struct memcg_stock_pcp *stock) 
		unsigned int nr_pages = stock->nr_bytes >> PAGE_SHIFT;

		unsigned int nr_bytes = stock->nr_bytes & (PAGE_SIZE - 1);



		if (nr_pages)

			obj_cgroup_uncharge_pages(old, nr_pages);

		if (nr_pages) {

			struct mem_cgroup *memcg;



			memcg = get_mem_cgroup_from_objcg(old);



			memcg_account_kmem(memcg, -nr_pages);

			__refill_stock(memcg, nr_pages);



			css_put(&memcg->css);

		}



		/*

		 * The leftover is flushed to the centralized per-memcg value.