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

Sebastian Andrzej Siewior
2013-02-13T16:41:35Z

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