mm: remove rest of ACCESS_ONCE() usages

We converted some of the usages of ACCESS_ONCE to READ_ONCE in the mm/
tree since it doesn't work reliably on non-scalar types.

This patch removes the rest of the usages of ACCESS_ONCE, and use the new
READ_ONCE API for the read accesses.  This makes things cleaner, instead
of using separate/multiple sets of APIs.

Signed-off-by: Jason Low <jason.low2@hp.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 9 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 74a9641d8f9f..14c2f2017e37 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -674,7 +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)
@@ -1042,7 +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(),
@@ -1359,13 +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);
 	}
@@ -2637,7 +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;
 
@@ -5007,7 +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);
@@ -5241,7 +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");
@@ -5271,7 +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");
@@ -5301,7 +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");