lkml.org 
[lkml]   [2015]   [Jan]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/6] mm/slab: fix gfp flags of percpu allocation at boot phase
Date
__alloc_percpu() passed GFP_KERNEL implicitly to core function of
percpu allocator. At boot phase, it's not valid gfp flag so change it.

Without this change, while implementing new feature, I found that
__alloc_percpu() calls kmalloc() which is not initialized at this time
and the system fail to boot. percpu allocator regards GFP_KERNEL as
the sign of the system fully initialized so aggressively try to make
spare room. With GFP_NOWAIT, it doesn't do that so succeed to boot.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
---
mm/slab.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/mm/slab.c b/mm/slab.c
index 65b5dcb..1150c8b 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1990,9 +1990,12 @@ static struct array_cache __percpu *alloc_kmem_cache_cpus(
int cpu;
size_t size;
struct array_cache __percpu *cpu_cache;
+ gfp_t gfp_flags = GFP_KERNEL;

size = sizeof(void *) * entries + sizeof(struct array_cache);
- cpu_cache = __alloc_percpu(size, sizeof(void *));
+ if (slab_state < FULL)
+ gfp_flags = GFP_NOWAIT;
+ cpu_cache = __alloc_percpu_gfp(size, sizeof(void *), gfp_flags);

if (!cpu_cache)
return NULL;
--
1.7.9.5


\
 
 \ /
  Last update: 2015-01-05 03:01    [W:2.123 / U:0.316 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site