Commit cfb4a541 authored by Mateusz Nosek's avatar Mateusz Nosek Committed by Linus Torvalds
Browse files

mm/page_alloc.c: micro-optimization remove unnecessary branch 



Previously flags check was separated into two separated checks with two
separated branches. In case of presence of any of two mentioned flags,
the same effect on flow occurs. Therefore checks can be merged and one
branch can be avoided.

Signed-off-by: default avatarMateusz Nosek <mateusznosek0@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20200911092310.31136-1-mateusznosek0@gmail.com


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b630749f

mm/page_alloc.c

+3 −5
Original line number Original line Diff line number Diff line
@@ -3986,8 +3986,10 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order, 
	 * success so it is time to admit defeat. We will skip the OOM killer

	 * success so it is time to admit defeat. We will skip the OOM killer

	 * because it is very likely that the caller has a more reasonable

	 * because it is very likely that the caller has a more reasonable

	 * fallback than shooting a random task.

	 * fallback than shooting a random task.

	 *

	 * The OOM killer may not free memory on a specific node.

	 */

	 */

	if (gfp_mask & __GFP_RETRY_MAYFAIL)

	if (gfp_mask & (__GFP_RETRY_MAYFAIL | __GFP_THISNODE))

		goto out;

		goto out;

	/* The OOM killer does not needlessly kill tasks for lowmem */

	/* The OOM killer does not needlessly kill tasks for lowmem */

	if (ac->highest_zoneidx < ZONE_NORMAL)

	if (ac->highest_zoneidx < ZONE_NORMAL)
@@ -4004,10 +4006,6 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order, 
	 * failures more gracefully we should just bail out here.

	 * failures more gracefully we should just bail out here.

	 */

	 */





	/* The OOM killer may not free memory on a specific node */

	if (gfp_mask & __GFP_THISNODE)

		goto out;



	/* Exhausted what can be done so it's blame time */

	/* Exhausted what can be done so it's blame time */

	if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {

	if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {

		*did_some_progress = 1;

		*did_some_progress = 1;