[PATCH 16/16] slub: Enable irqs for __GFP_WAIT

[Sebastian Andrzej Siewior <bigeasy@linutronix.de>]

From: Thomas Gleixner <tglx@linutronix.de>

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>
[bigeasy@linutronix: fix !page conflict]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 mm/slub.c |   13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index 8475580..4c62b7f 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1285,14 +1285,15 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
 	struct page *page;
 	struct kmem_cache_order_objects oo = s->oo;
 	gfp_t alloc_gfp;
+	bool enableirqs;
 
 	flags &= gfp_allowed_mask;
 
+	enableirqs = (flags & __GFP_WAIT) != 0;
 #ifdef CONFIG_PREEMPT_RT_FULL
-	if (system_state == SYSTEM_RUNNING)
-#else
-	if (flags & __GFP_WAIT)
+	enableirqs |= system_state == SYSTEM_RUNNING;
 #endif
+	if (enableirqs)
 		local_irq_enable();
 
 	flags |= s->allocflags;
@@ -1316,11 +1317,7 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
 			stat(s, ORDER_FALLBACK);
 	}
 
-#ifdef CONFIG_PREEMPT_RT_FULL
-	if (system_state == SYSTEM_RUNNING)
-#else
-	if (flags & __GFP_WAIT)
-#endif
+	if (enableirqs)
 		local_irq_disable();
 
 	if (!page)
-- 
1.7.10.4