[PATCH] sysctl_panic_on_oom broken

[Larry Woodman]

out_of_memory() does not panic when sysctl_panic_on_oom is set
if constrained_alloc() does not return CONSTRAINT_NONE.  Instead,
out_of_memory() kills the current process whenever constrained_alloc()
returns either CONSTRAINT_MEMORY_POLICY or CONSTRAINT_CPUSET.
This patch fixes this problem:

Signed-off-by: Larry Woodman <lwoodman@xxxxxxxxxx>



--- linux-2.6.18.noarch/mm/oom_kill.c.orig
+++ linux-2.6.18.noarch/mm/oom_kill.c
@@ -431,6 +437,9 @@ void out_of_memory(struct zonelist *zone
 	cpuset_lock();
 	read_lock(&tasklist_lock);
 
+	/* check if we are going to panic before enything else... */
+	if (sysctl_panic_on_oom)
+		panic("out of memory. panic_on_oom is selected\n");
 	/*
 	 * Check if there were limitations on the allocation (only relevant for
 	 * NUMA) that may require different handling.
@@ -447,8 +456,6 @@ void out_of_memory(struct zonelist *zone
 		break;
 
 	case CONSTRAINT_NONE:
-		if (sysctl_panic_on_oom)
-			panic("out of memory. panic_on_oom is selected\n");
 retry:
 		/*
 		 * Rambo mode: Shoot down a process and hope it solves whatever