Re: SLUB ia64 linux-next crash bisected to 756dee75

[Christoph Lameter <cl@linux-foundation.org>]

On Thu, 21 Jan 2010, Alex Chiang wrote:

> > Looks like percpu data is corrupted. One of my earlier fixes dimensioned
> > the kmem_cache_cpu array correctly. That is missing here.
>
> Ah, that was pilot error on my part. I didn't realize that the
> second patch you sent was to be in combination with the first.
> Sorry about that.

Difficult since I also did not track how this belonged together. Sorry.


From: Christoph Lameter <cl@linux-foundation.org>
Subject: [SLUB] dma kmalloc handling fixes

1. We need kmalloc_percpu for all of the now extended kmalloc caches
   array not just for each shift value.

2. init_kmem_cache_nodes() must assume node 0 locality for statically
   allocated dma kmem_cache structures even after boot is complete.

Reported-and-tested-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>

---
 mm/slub.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c	2010-01-21 16:39:26.000000000 -0600
+++ linux-2.6/mm/slub.c	2010-01-21 16:40:35.000000000 -0600
@@ -2086,7 +2086,7 @@ init_kmem_cache_node(struct kmem_cache_n
 #endif
 }

-static DEFINE_PER_CPU(struct kmem_cache_cpu, kmalloc_percpu[SLUB_PAGE_SHIFT]);
+static DEFINE_PER_CPU(struct kmem_cache_cpu, kmalloc_percpu[KMALLOC_CACHES]);

 static inline int alloc_kmem_cache_cpus(struct kmem_cache *s, gfp_t flags)
 {
@@ -2176,7 +2176,8 @@ static int init_kmem_cache_nodes(struct
 	int node;
 	int local_node;

-	if (slab_state >= UP)
+	if (slab_state >= UP && (s < kmalloc_caches ||
+			s > kmalloc_caches + KMALLOC_CACHES))
 		local_node = page_to_nid(virt_to_page(s));
 	else
 		local_node = 0;

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