Merge branch 'linux-linaro-lsk' into linux-linaro-lsk-android

[firefly-linux-kernel-4.4.55.git] / kernel / freezer.c

diff --git a/kernel/freezer.c b/kernel/freezer.c
index 78758512b1e1ef6994bb91371e5bbe5e8a43e686..5420f635111f4b0b9d28760276424e6aa39a7b21 100644 (file)
--- a/kernel/freezer.c
+++ b/kernel/freezer.c
@@ -116,6 +116,18 @@ bool freeze_task(struct task_struct *p)
 {
        unsigned long flags;
 
+       /*
+        * This check can race with freezer_do_not_count, but worst case that
+        * will result in an extra wakeup being sent to the task.  It does not
+        * race with freezer_count(), the barriers in freezer_count() and
+        * freezer_should_skip() ensure that either freezer_count() sees
+        * freezing == true in try_to_freeze() and freezes, or
+        * freezer_should_skip() sees !PF_FREEZE_SKIP and freezes the task
+        * normally.
+        */
+       if (freezer_should_skip(p))
+               return false;
+
        spin_lock_irqsave(&freezer_lock, flags);
        if (!freezing(p) || frozen(p)) {
                spin_unlock_irqrestore(&freezer_lock, flags);