diff options
Diffstat (limited to 'mm/memcontrol.c')
| -rw-r--r-- | mm/memcontrol.c | 47 |
1 files changed, 17 insertions, 30 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index c3f09b2dda5f..14c2f2017e37 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -259,11 +259,6 @@ static void mem_cgroup_oom_notify(struct mem_cgroup *memcg); * page cache and RSS per cgroup. We would eventually like to provide * statistics based on the statistics developed by Rik Van Riel for clock-pro, * to help the administrator determine what knobs to tune. - * - * TODO: Add a water mark for the memory controller. Reclaim will begin when - * we hit the water mark. May be even add a low water mark, such that - * no reclaim occurs from a cgroup at it's low water mark, this is - * a feature that will be implemented much later in the future. */ struct mem_cgroup { struct cgroup_subsys_state css; @@ -460,6 +455,12 @@ static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg) return memcg->css.id; } +/* + * A helper function to get mem_cgroup from ID. must be called under + * rcu_read_lock(). The caller is responsible for calling + * css_tryget_online() if the mem_cgroup is used for charging. (dropping + * refcnt from swap can be called against removed memcg.) + */ static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id) { struct cgroup_subsys_state *css; @@ -673,7 +674,7 @@ static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone *mz, static unsigned long soft_limit_excess(struct mem_cgroup *memcg) { unsigned long nr_pages = page_counter_read(&memcg->memory); - unsigned long soft_limit = ACCESS_ONCE(memcg->soft_limit); + unsigned long soft_limit = READ_ONCE(memcg->soft_limit); unsigned long excess = 0; if (nr_pages > soft_limit) @@ -1041,7 +1042,7 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, goto out_unlock; do { - pos = ACCESS_ONCE(iter->position); + pos = READ_ONCE(iter->position); /* * A racing update may change the position and * put the last reference, hence css_tryget(), @@ -1358,13 +1359,13 @@ static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg) unsigned long limit; count = page_counter_read(&memcg->memory); - limit = ACCESS_ONCE(memcg->memory.limit); + limit = READ_ONCE(memcg->memory.limit); if (count < limit) margin = limit - count; if (do_swap_account) { count = page_counter_read(&memcg->memsw); - limit = ACCESS_ONCE(memcg->memsw.limit); + limit = READ_ONCE(memcg->memsw.limit); if (count <= limit) margin = min(margin, limit - count); } @@ -2349,20 +2350,6 @@ static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages) } /* - * A helper function to get mem_cgroup from ID. must be called under - * rcu_read_lock(). The caller is responsible for calling - * css_tryget_online() if the mem_cgroup is used for charging. (dropping - * refcnt from swap can be called against removed memcg.) - */ -static struct mem_cgroup *mem_cgroup_lookup(unsigned short id) -{ - /* ID 0 is unused ID */ - if (!id) - return NULL; - return mem_cgroup_from_id(id); -} - -/* * try_get_mem_cgroup_from_page - look up page's memcg association * @page: the page * @@ -2388,7 +2375,7 @@ struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) ent.val = page_private(page); id = lookup_swap_cgroup_id(ent); rcu_read_lock(); - memcg = mem_cgroup_lookup(id); + memcg = mem_cgroup_from_id(id); if (memcg && !css_tryget_online(&memcg->css)) memcg = NULL; rcu_read_unlock(); @@ -2650,7 +2637,7 @@ struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep) return cachep; memcg = get_mem_cgroup_from_mm(current->mm); - kmemcg_id = ACCESS_ONCE(memcg->kmemcg_id); + kmemcg_id = READ_ONCE(memcg->kmemcg_id); if (kmemcg_id < 0) goto out; @@ -5020,7 +5007,7 @@ static int mem_cgroup_can_attach(struct cgroup_subsys_state *css, * tunable will only affect upcoming migrations, not the current one. * So we need to save it, and keep it going. */ - move_flags = ACCESS_ONCE(memcg->move_charge_at_immigrate); + move_flags = READ_ONCE(memcg->move_charge_at_immigrate); if (move_flags) { struct mm_struct *mm; struct mem_cgroup *from = mem_cgroup_from_task(p); @@ -5254,7 +5241,7 @@ static u64 memory_current_read(struct cgroup_subsys_state *css, static int memory_low_show(struct seq_file *m, void *v) { struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); - unsigned long low = ACCESS_ONCE(memcg->low); + unsigned long low = READ_ONCE(memcg->low); if (low == PAGE_COUNTER_MAX) seq_puts(m, "max\n"); @@ -5284,7 +5271,7 @@ static ssize_t memory_low_write(struct kernfs_open_file *of, static int memory_high_show(struct seq_file *m, void *v) { struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); - unsigned long high = ACCESS_ONCE(memcg->high); + unsigned long high = READ_ONCE(memcg->high); if (high == PAGE_COUNTER_MAX) seq_puts(m, "max\n"); @@ -5314,7 +5301,7 @@ static ssize_t memory_high_write(struct kernfs_open_file *of, static int memory_max_show(struct seq_file *m, void *v) { struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); - unsigned long max = ACCESS_ONCE(memcg->memory.limit); + unsigned long max = READ_ONCE(memcg->memory.limit); if (max == PAGE_COUNTER_MAX) seq_puts(m, "max\n"); @@ -5869,7 +5856,7 @@ void mem_cgroup_uncharge_swap(swp_entry_t entry) id = swap_cgroup_record(entry, 0); rcu_read_lock(); - memcg = mem_cgroup_lookup(id); + memcg = mem_cgroup_from_id(id); if (memcg) { if (!mem_cgroup_is_root(memcg)) page_counter_uncharge(&memcg->memsw, 1); |