oom: add oom_kill_allocating_task sysctl
Adds a new sysctl, 'oom_kill_allocating_task', which will automatically kill
the OOM-triggering task instead of scanning through the tasklist to find a
memory-hogging target. This is helpful for systems with an insanely large
number of tasks where scanning the tasklist significantly degrades
performance.
Cc: Andrea Arcangeli <andrea@suse.de>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 6e999c8..00d0bd7 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -27,6 +27,7 @@
#include <linux/notifier.h>
int sysctl_panic_on_oom;
+int sysctl_oom_kill_allocating_task;
static DEFINE_MUTEX(zone_scan_mutex);
/* #define DEBUG */
@@ -471,14 +472,16 @@
"No available memory (MPOL_BIND)");
break;
- case CONSTRAINT_CPUSET:
- oom_kill_process(current, points,
- "No available memory in cpuset");
- break;
-
case CONSTRAINT_NONE:
if (sysctl_panic_on_oom)
panic("out of memory. panic_on_oom is selected\n");
+ /* Fall-through */
+ case CONSTRAINT_CPUSET:
+ if (sysctl_oom_kill_allocating_task) {
+ oom_kill_process(current, points,
+ "Out of memory (oom_kill_allocating_task)");
+ break;
+ }
retry:
/*
* Rambo mode: Shoot down a process and hope it solves whatever