mm, oom: rename zonelist locking functions

try_set_zonelist_oom() and clear_zonelist_oom() are not named properly
to imply that they require locking semantics to avoid out_of_memory()
being reordered.

zone_scan_lock is required for both functions to ensure that there is
proper locking synchronization.

Rename try_set_zonelist_oom() to oom_zonelist_trylock() and rename
clear_zonelist_oom() to oom_zonelist_unlock() to imply there is proper
locking semantics.

At the same time, convert oom_zonelist_trylock() to return bool instead
of int since only success and failure are tested.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index fb99081..5782360 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2246,8 +2246,8 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
 {
 	struct page *page;
 
-	/* Acquire the OOM killer lock for the zones in zonelist */
-	if (!try_set_zonelist_oom(zonelist, gfp_mask)) {
+	/* Acquire the per-zone oom lock for each zone */
+	if (!oom_zonelist_trylock(zonelist, gfp_mask)) {
 		schedule_timeout_uninterruptible(1);
 		return NULL;
 	}
@@ -2285,7 +2285,7 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
 	out_of_memory(zonelist, gfp_mask, order, nodemask, false);
 
 out:
-	clear_zonelist_oom(zonelist, gfp_mask);
+	oom_zonelist_unlock(zonelist, gfp_mask);
 	return page;
 }