Hello.

Should selected_tasksize be added to rem even when TIF_MEMDIE was not set?

Please see a thread from http://www.spinics.net/lists/linux-mm/msg93246.html
if you want to know why to reverse the order.
----------------------------------------
>From 2d4cc11d8128e4c1397631b91fea78da3eaefb47 Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-ker...@i-love.sakura.ne.jp>
Date: Wed, 26 Aug 2015 20:52:39 +0900
Subject: [PATCH 2/2] android, lmk: Reverse the order of setting TIF_MEMDIE and 
sending SIGKILL.

If we set TIF_MEMDIE before sending SIGKILL, memory reserves could be
spent for allocations which are not needed for terminating the victim.
Reverse the order as with oom_kill_process() does.

Signed-off-by: Tetsuo Handa <penguin-ker...@i-love.sakura.ne.jp>
---
 drivers/staging/android/lowmemorykiller.c | 24 +++++++++++-------------
 1 file changed, 11 insertions(+), 13 deletions(-)

diff --git a/drivers/staging/android/lowmemorykiller.c 
b/drivers/staging/android/lowmemorykiller.c
index d5d25e4..c39b6a2 100644
--- a/drivers/staging/android/lowmemorykiller.c
+++ b/drivers/staging/android/lowmemorykiller.c
@@ -156,26 +156,24 @@ next:
        }
        if (selected) {
                task_lock(selected);
-               if (!selected->mm) {
-                       /* Already exited, cannot do mark_tsk_oom_victim() */
-                       task_unlock(selected);
-                       goto out;
-               }
+               lowmem_print(1, "send sigkill to %d (%s), adj %hd, size %d\n",
+                            selected->pid, selected->comm,
+                            selected_oom_score_adj, selected_tasksize);
+               task_unlock(selected);
+               send_sig(SIGKILL, selected, 0);
                /*
                 * FIXME: lowmemorykiller shouldn't abuse global OOM killer
                 * infrastructure. There is no real reason why the selected
                 * task should have access to the memory reserves.
                 */
-               mark_oom_victim(selected);
-               lowmem_print(1, "send sigkill to %d (%s), adj %hd, size %d\n",
-                            selected->pid, selected->comm,
-                            selected_oom_score_adj, selected_tasksize);
+               task_lock(selected);
+               if (selected->mm) {
+                       mark_oom_victim(selected);
+                       lowmem_deathpending_timeout = jiffies + HZ;
+                       rem += selected_tasksize;
+               }
                task_unlock(selected);
-               lowmem_deathpending_timeout = jiffies + HZ;
-               send_sig(SIGKILL, selected, 0);
-               rem += selected_tasksize;
        }
-out:
        lowmem_print(4, "lowmem_scan %lu, %x, return %lu\n",
                     sc->nr_to_scan, sc->gfp_mask, rem);
        rcu_read_unlock();
-- 
1.8.3.1
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