From 88c8004fd3a5fdd2378069de86b90b21110d33a4 Mon Sep 17 00:00:00 2001 From: Colin Cross Date: Wed, 1 May 2013 18:35:05 -0700 Subject: [PATCH] futex: Use freezable blocking call Avoid waking up every thread sleeping in a futex_wait call during suspend and resume by calling a freezable blocking call. Previous patches modified the freezer to avoid sending wakeups to threads that are blocked in freezable blocking calls. This call was selected to be converted to a freezable call because it doesn't hold any locks or release any resources when interrupted that might be needed by another freezing task or a kernel driver during suspend, and is a common site where idle userspace tasks are blocked. Signed-off-by: Colin Cross Cc: Rafael J. Wysocki Cc: arve@android.com Cc: Tejun Heo Cc: Oleg Nesterov Cc: Darren Hart Cc: Randy Dunlap Cc: Al Viro Link: http://lkml.kernel.org/r/1367458508-9133-8-git-send-email-ccross@android.com Signed-off-by: Thomas Gleixner --- kernel/futex.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/futex.c b/kernel/futex.c index 49dacfb45745..c3a1a55a5214 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -62,6 +62,7 @@ #include #include #include +#include #include @@ -1808,7 +1809,7 @@ static void futex_wait_queue_me(struct futex_hash_bucket *hb, struct futex_q *q, * is no timeout, or if it has yet to expire. */ if (!timeout || timeout->task) - schedule(); + freezable_schedule(); } __set_current_state(TASK_RUNNING); }