From: Thomas Gleixner <tglx@linutronix.de>
Date: Fri, 8 Jul 2011 16:35:35 +0200
Subject: fs/epoll: Do not disable preemption on RT
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git
Git-commit: 53e95048823c782b0b8dedbb23acdc6a9c3c9adc
Patch-mainline: Queued in subsystem maintainer repository
References: SLE Realtime Extension

ep_call_nested() takes a sleeping lock so we can't disable preemption.
The light version is enough since ep_call_nested() doesn't mind beeing
invoked twice on the same CPU.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Mike Galbraith <mgalbraith@suse.de>
---
 fs/eventpoll.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -562,12 +562,12 @@ static int ep_poll_wakeup_proc(void *pri
 
 static void ep_poll_safewake(wait_queue_head_t *wq)
 {
-	int this_cpu = get_cpu();
+	int this_cpu = get_cpu_light();
 
 	ep_call_nested(&poll_safewake_ncalls, EP_MAX_NESTS,
 		       ep_poll_wakeup_proc, NULL, wq, (void *) (long) this_cpu);
 
-	put_cpu();
+	put_cpu_light();
 }
 
 #else