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Commit 567e9ab2 authored by Johannes Weiner's avatar Johannes Weiner Committed by Linus Torvalds
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mm: memcontrol: give the kmem states more descriptive names 



On any given memcg, the kmem accounting feature has three separate
states: not initialized, structures allocated, and actively accounting
slab memory.  These are represented through a combination of the
kmem_acct_activated and kmem_acct_active flags, which is confusing.

Convert to a kmem_state enum with the states NONE, ALLOCATED, and
ONLINE.  Then rename the functions to modify the state accordingly.
This follows the nomenclature of css object states more closely.

Signed-off-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: default avatarVladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b15aac11

include/linux/memcontrol.h

+10 −5
Original line number Diff line number Diff line
@@ -152,6 +152,12 @@ struct mem_cgroup_thresholds { 
	struct mem_cgroup_threshold_ary *spare;

};



enum memcg_kmem_state {

	KMEM_NONE,

	KMEM_ALLOCATED,

	KMEM_ONLINE,

};



/*

 * The memory controller data structure. The memory controller controls both

 * page cache and RSS per cgroup. We would eventually like to provide
@@ -233,8 +239,7 @@ struct mem_cgroup { 
#if defined(CONFIG_MEMCG_KMEM)

        /* Index in the kmem_cache->memcg_params.memcg_caches array */

	int kmemcg_id;

	bool kmem_acct_activated;

	bool kmem_acct_active;

	enum memcg_kmem_state kmem_state;

#endif



	int last_scanned_node;
@@ -750,9 +755,9 @@ static inline bool memcg_kmem_enabled(void) 
	return static_branch_unlikely(&memcg_kmem_enabled_key);

}



static inline bool memcg_kmem_is_active(struct mem_cgroup *memcg)

static inline bool memcg_kmem_online(struct mem_cgroup *memcg)

{

	return memcg->kmem_acct_active;

	return memcg->kmem_state == KMEM_ONLINE;

}



/*
@@ -850,7 +855,7 @@ static inline bool memcg_kmem_enabled(void) 
	return false;

}



static inline bool memcg_kmem_is_active(struct mem_cgroup *memcg)

static inline bool memcg_kmem_online(struct mem_cgroup *memcg)

{

	return false;

}

mm/memcontrol.c

+25 −27
Original line number Diff line number Diff line
@@ -2378,7 +2378,7 @@ int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order, 
	struct page_counter *counter;

	int ret;



	if (!memcg_kmem_is_active(memcg))

	if (!memcg_kmem_online(memcg))

		return 0;



	if (!page_counter_try_charge(&memcg->kmem, nr_pages, &counter))
@@ -2861,14 +2861,13 @@ static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css, 
}



#ifdef CONFIG_MEMCG_KMEM

static int memcg_activate_kmem(struct mem_cgroup *memcg)

static int memcg_online_kmem(struct mem_cgroup *memcg)

{

	int err = 0;

	int memcg_id;



	BUG_ON(memcg->kmemcg_id >= 0);

	BUG_ON(memcg->kmem_acct_activated);

	BUG_ON(memcg->kmem_acct_active);

	BUG_ON(memcg->kmem_state);



	/*

	 * For simplicity, we won't allow this to be disabled.  It also can't
@@ -2898,14 +2897,13 @@ static int memcg_activate_kmem(struct mem_cgroup *memcg) 


	static_branch_inc(&memcg_kmem_enabled_key);

	/*

	 * A memory cgroup is considered kmem-active as soon as it gets

	 * A memory cgroup is considered kmem-online as soon as it gets

	 * kmemcg_id. Setting the id after enabling static branching will

	 * guarantee no one starts accounting before all call sites are

	 * patched.

	 */

	memcg->kmemcg_id = memcg_id;

	memcg->kmem_acct_activated = true;

	memcg->kmem_acct_active = true;

	memcg->kmem_state = KMEM_ONLINE;

out:

	return err;

}
@@ -2917,8 +2915,8 @@ static int memcg_update_kmem_limit(struct mem_cgroup *memcg, 


	mutex_lock(&memcg_limit_mutex);

	/* Top-level cgroup doesn't propagate from root */

	if (!memcg_kmem_is_active(memcg)) {

		ret = memcg_activate_kmem(memcg);

	if (!memcg_kmem_online(memcg)) {

		ret = memcg_online_kmem(memcg);

		if (ret)

			goto out;

	}
@@ -2938,11 +2936,12 @@ static int memcg_propagate_kmem(struct mem_cgroup *memcg) 


	mutex_lock(&memcg_limit_mutex);

	/*

	 * If the parent cgroup is not kmem-active now, it cannot be activated

	 * after this point, because it has at least one child already.

	 * If the parent cgroup is not kmem-online now, it cannot be

	 * onlined after this point, because it has at least one child

	 * already.

	 */

	if (memcg_kmem_is_active(parent))

		ret = memcg_activate_kmem(memcg);

	if (memcg_kmem_online(parent))

		ret = memcg_online_kmem(memcg);

	mutex_unlock(&memcg_limit_mutex);

	return ret;

}
@@ -3590,22 +3589,21 @@ static int memcg_init_kmem(struct mem_cgroup *memcg) 
	return tcp_init_cgroup(memcg);

}



static void memcg_deactivate_kmem(struct mem_cgroup *memcg)

static void memcg_offline_kmem(struct mem_cgroup *memcg)

{

	struct cgroup_subsys_state *css;

	struct mem_cgroup *parent, *child;

	int kmemcg_id;



	if (!memcg->kmem_acct_active)

	if (memcg->kmem_state != KMEM_ONLINE)

		return;



	/*

	 * Clear the 'active' flag before clearing memcg_caches arrays entries.

	 * Since we take the slab_mutex in memcg_deactivate_kmem_caches(), it

	 * guarantees no cache will be created for this cgroup after we are

	 * done (see memcg_create_kmem_cache()).

	 * Clear the online state before clearing memcg_caches array

	 * entries. The slab_mutex in memcg_deactivate_kmem_caches()

	 * guarantees that no cache will be created for this cgroup

	 * after we are done (see memcg_create_kmem_cache()).

	 */

	memcg->kmem_acct_active = false;

	memcg->kmem_state = KMEM_ALLOCATED;



	memcg_deactivate_kmem_caches(memcg);
@@ -3636,9 +3634,9 @@ static void memcg_deactivate_kmem(struct mem_cgroup *memcg) 
	memcg_free_cache_id(kmemcg_id);

}



static void memcg_destroy_kmem(struct mem_cgroup *memcg)

static void memcg_free_kmem(struct mem_cgroup *memcg)

{

	if (memcg->kmem_acct_activated) {

	if (memcg->kmem_state == KMEM_ALLOCATED) {

		memcg_destroy_kmem_caches(memcg);

		static_branch_dec(&memcg_kmem_enabled_key);

		WARN_ON(page_counter_read(&memcg->kmem));
@@ -3651,11 +3649,11 @@ static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) 
	return 0;

}



static void memcg_deactivate_kmem(struct mem_cgroup *memcg)

static void memcg_offline_kmem(struct mem_cgroup *memcg)

{

}



static void memcg_destroy_kmem(struct mem_cgroup *memcg)

static void memcg_free_kmem(struct mem_cgroup *memcg)

{

}

#endif
@@ -4308,7 +4306,7 @@ static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) 


	vmpressure_cleanup(&memcg->vmpressure);



	memcg_deactivate_kmem(memcg);

	memcg_offline_kmem(memcg);



	wb_memcg_offline(memcg);

}
@@ -4324,7 +4322,7 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css) 
{

	struct mem_cgroup *memcg = mem_cgroup_from_css(css);



	memcg_destroy_kmem(memcg);

	memcg_free_kmem(memcg);

#ifdef CONFIG_INET

	if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket)

		static_branch_dec(&memcg_sockets_enabled_key);

mm/slab_common.c

+2 −2
Original line number Diff line number Diff line
@@ -503,10 +503,10 @@ void memcg_create_kmem_cache(struct mem_cgroup *memcg, 
	mutex_lock(&slab_mutex);



	/*

	 * The memory cgroup could have been deactivated while the cache

	 * The memory cgroup could have been offlined while the cache

	 * creation work was pending.

	 */

	if (!memcg_kmem_is_active(memcg))

	if (!memcg_kmem_online(memcg))

		goto out_unlock;



	idx = memcg_cache_id(memcg);

mm/vmscan.c

+1 −1
Original line number Diff line number Diff line
@@ -411,7 +411,7 @@ static unsigned long shrink_slab(gfp_t gfp_mask, int nid, 
	struct shrinker *shrinker;

	unsigned long freed = 0;



	if (memcg && !memcg_kmem_is_active(memcg))

	if (memcg && !memcg_kmem_online(memcg))

		return 0;



	if (nr_scanned == 0)