From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 9 Jan 2013 12:08:15 +0100
Subject: slub: Enable irqs for __GFP_WAIT
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git
Git-commit: bda297ffdcb4379e242f126ed76659aa08b2284e
Patch-mainline: Queued in subsystem maintainer repository
References: SLE Realtime Extension

SYSTEM_RUNNING might be too late for enabling interrupts. Allocations
with GFP_WAIT can happen before that. So use this as an indicator.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Mike Galbraith <mgalbraith@suse.de>
---
 mm/slub.c |   13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1538,14 +1538,17 @@ static struct page *allocate_slab(struct
 	void *start, *p;
 	int idx, order;
 	bool shuffle;
+	bool enableirqs = false;
 
 	flags &= gfp_allowed_mask;
 
+	if (gfpflags_allow_blocking(flags))
+		enableirqs = true;
 #ifdef CONFIG_PREEMPT_RT_FULL
 	if (system_state > SYSTEM_BOOTING)
-#else
-	if (gfpflags_allow_blocking(flags))
+		enableirqs = true;
 #endif
+	if (enableirqs)
 		local_irq_enable();
 
 	flags |= s->allocflags;
@@ -1620,11 +1623,7 @@ static struct page *allocate_slab(struct
 	page->frozen = 1;
 
 out:
-#ifdef CONFIG_PREEMPT_RT_FULL
-	if (system_state > SYSTEM_BOOTING)
-#else
-	if (gfpflags_allow_blocking(flags))
-#endif
+	if (enableirqs)
 		local_irq_disable();
 	if (!page)
 		return NULL;