mm/oom_kill: squashed reverts to a stable state

Revert "mm, oom: fix use-after-free in oom_kill_process"

This reverts commit e1bebdeedb497f03d426c85a89c3807c7e75268d.

Signed-off-by: Corinna Vinschen <xda@vinschen.de>

Revert "mm,oom: make oom_killer_disable() killable"

This reverts commit 65a7400a432639aa8d5e572f30687fbca204b6f8.

Signed-off-by: Corinna Vinschen <xda@vinschen.de>

Revert "mm: oom_kill: don't ignore oom score on exiting tasks"

This reverts commit d60dae46b27a8f381e4a7ad9dde870faa49fa5f1.

Signed-off-by: Corinna Vinschen <xda@vinschen.de>

Revert "mm/oom_kill.c: avoid attempting to kill init sharing same memory"

This reverts commit 10773c0325259d6640b93c0694b5598ddf84939f.

Signed-off-by: Corinna Vinschen <xda@vinschen.de>

Revert "CHROMIUM: DROP: mm/oom_kill: Double-check before killing a child in our place"

This reverts commit 2bdd9a2042a0e12d96c545773d9d8038c920f813.

Revert "mm/oom_kill: fix the wrong task->mm == mm checks in oom_kill_process()"

This reverts commit 419a313435b31821e4d045ca4b7ea1cc5fa02035.

Signed-off-by: Corinna Vinschen <xda@vinschen.de>

Revert "mm/oom_kill: cleanup the "kill sharing same memory" loop"

This reverts commit afda78c6de38f9f66eba0955153b380d540d8276.

Revert "mm/oom_kill: remove the wrong fatal_signal_pending() check in oom_kill_process()"

This reverts commit acde9c2ace298b249c06ec5b0b971c333449dc09.

Signed-off-by: Corinna Vinschen <xda@vinschen.de>

Revert "mm, oom: remove task_lock protecting comm printing"

This reverts commit 9a9ca142d250ec9de1215284857f4528c6ddb080.

Signed-off-by: Corinna Vinschen <xda@vinschen.de>

Revert "mm/oom_kill.c: suppress unnecessary "sharing same memory" message"

This reverts commit 1aa2960f7c70d65b1481f805ac73b988faff6747.

Signed-off-by: Corinna Vinschen <xda@vinschen.de>

Revert "mm/oom_kill.c: reverse the order of setting TIF_MEMDIE and sending SIGKILL"

This reverts commit f028aedfcfd2e2bb98921b98d3ae183387ab8fed.

Revert "mm, oom: remove unnecessary variable"

This reverts commit 54b0b58224146d68a11bccb5e64683ab3029373a.

Revert "mm/oom_kill.c: print points as unsigned int"

This reverts commit 603f975a6d4f0b56c7f6df7889ef2a704eca94a3.

Signed-off-by: Corinna Vinschen <xda@vinschen.de>

Revert "mm: oom_kill: simplify OOM killer locking"

This reverts commit 7951a52ed35d162063fa08b27894e302fd716ccd.

Revert "mm: oom_kill: remove unnecessary locking in exit_oom_victim()"

This reverts commit f0739b25ac884682865d6aae7485e79489107bfb.

Revert "mm: oom_kill: generalize OOM progress waitqueue"

This reverts commit eb4b1243c72ba0b392bbe05dbf9f91959f70eb18.

Revert "mm: oom_kill: switch test-and-clear of known TIF_MEMDIE to clear"

This reverts commit e611f16275c3642cb8a6345ff2470926fef52110.

Revert "mm: oom_kill: clean up victim marking and exiting interfaces"

This reverts commit c6fada01b9370e3d7603b4ad8c26b56759174667.

Revert "mm: oom_kill: remove unnecessary locking in oom_enable()"

This reverts commit 5dd152d7351b3805f59b2b1f624722ab2f3c5fd8.

Revert "oom, PM: make OOM detection in the freezer path raceless"

This reverts commit 5fc5b1ddee5404a7629dd7045f54eaf8941bc11c.

1 files changed, 9 insertions, 13 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b843aeeb3..f58bcb213 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1807,16 +1807,14 @@ static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
 	unsigned int points = 0;
 	struct task_struct *chosen = NULL;
 
-	mutex_lock(&oom_lock);
-
 	/*
 	 * If current has a pending SIGKILL or is exiting, then automatically
 	 * select it.  The goal is to allow it to allocate so that it may
 	 * quickly exit and free its memory.
 	 */
 	if (fatal_signal_pending(current) || task_will_free_mem(current)) {
-		mark_oom_victim(current);
-		goto unlock;
+		mark_tsk_oom_victim(current);
+		return;
 	}
 
 	check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, order, NULL);
@@ -1844,7 +1842,7 @@ static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
 				mem_cgroup_iter_break(memcg, iter);
 				if (chosen)
 					put_task_struct(chosen);
-				goto unlock;
+				return;
 			case OOM_SCAN_OK:
 				break;
 			};
@@ -1865,13 +1863,11 @@ static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
 		cgroup_iter_end(cgroup, &it);
 	}
 
-	if (chosen) {
-		points = chosen_points * 1000 / totalpages;
-		oom_kill_process(chosen, gfp_mask, order, points, totalpages,
-				 memcg, NULL, "Memory cgroup out of memory");
-	}
-unlock:
-	mutex_unlock(&oom_lock);
+	if (!chosen)
+		return;
+	points = chosen_points * 1000 / totalpages;
+	oom_kill_process(chosen, gfp_mask, order, points, totalpages, memcg,
+			 NULL, "Memory cgroup out of memory");
 }
 
 static unsigned long mem_cgroup_reclaim(struct mem_cgroup *memcg,
@@ -2266,7 +2262,7 @@ bool mem_cgroup_oom_synchronize(bool handle)
 	if (!memcg)
 		return false;
 
-	if (!handle || oom_killer_disabled)
+	if (!handle)
 		goto cleanup;
 
 	owait.memcg = memcg;