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-rw-r--r--mm/memcontrol.c47
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);