[PATCH] oom: break after selecting process to kill

[Niv Yehezkel <executerx@gmail.com>]

There is no need to fallback and continue computing
badness for each running process after we have found a
process currently performing the swapoff syscall. We ought to
immediately select this process for killing.

Signed-off-by: Niv Yehezkel <executerx@gmail.com>
---
 mm/oom_kill.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 1e11df8..68ac30e 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -305,6 +305,7 @@ static struct task_struct *select_bad_process(unsigned int *ppoints,
 	struct task_struct *g, *p;
 	struct task_struct *chosen = NULL;
 	unsigned long chosen_points = 0;
+	bool process_selected = false;
 
 	rcu_read_lock();
 	for_each_process_thread(g, p) {
@@ -315,7 +316,8 @@ static struct task_struct *select_bad_process(unsigned int *ppoints,
 		case OOM_SCAN_SELECT:
 			chosen = p;
 			chosen_points = ULONG_MAX;
-			/* fall through */
+			process_selected = true;
+			break;
 		case OOM_SCAN_CONTINUE:
 			continue;
 		case OOM_SCAN_ABORT:
@@ -324,6 +326,8 @@ static struct task_struct *select_bad_process(unsigned int *ppoints,
 		case OOM_SCAN_OK:
 			break;
 		};
+		if (process_selected)
+			break;
 		points = oom_badness(p, NULL, nodemask, totalpages);
 		if (!points || points < chosen_points)
 			continue;
-- 
1.7.10.4

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