Messages in this thread Patch in this message | | | Date | Fri, 21 Mar 2008 21:02:35 -0400 | From | Joe Korty <> | Subject | Re: [patch 00/76] 2.6.24-stable review |
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On Fri, Mar 21, 2008 at 03:42:50PM -0700, Chris Wright wrote: > This is the start of the stable review cycle for the 2.6.24.4 release.
Hi Chris, The below is also a candidate for 2.6.24.4. It should apply cleanly. Joe
Gitweb: http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=6d2144d355d2a532e5cc3fc12a6ba2a8d4ef15e4 Commit: 6d2144d355d2a532e5cc3fc12a6ba2a8d4ef15e4 Parent: b6210386787728b84db25adc4f1eba70440a4c73 Author: Joe Korty <joe.korty@ccur.com> AuthorDate: Wed Mar 5 15:04:59 2008 -0800 Committer: Christoph Lameter <clameter@sgi.com> CommitDate: Thu Mar 6 16:21:50 2008 -0800
slab: NUMA slab allocator migration bugfix
NUMA slab allocator cpu migration bugfix
The NUMA slab allocator (specifically, cache_alloc_refill) is not refreshing its local copies of what cpu and what numa node it is on, when it drops and reacquires the irq block that it inherited from its caller. As a result those values become invalid if an attempt to migrate the process to another numa node occured while the irq block had been dropped.
The solution is to make cache_alloc_refill reload these variables whenever it drops and reacquires the irq block.
The error is very difficult to hit. When it does occur, one gets the following oops + stack traceback bits in check_spinlock_acquired:
kernel BUG at mm/slab.c:2417 cache_alloc_refill+0xe6 kmem_cache_alloc+0xd0 ...
This patch was developed against 2.6.23, ported to and compiled-tested only against 2.6.25-rc4.
Signed-off-by: Joe Korty <joe.korty@ccur.com> Signed-off-by: Christoph Lameter <clameter@sgi.com> --- mm/slab.c | 5 ++--- 1 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/mm/slab.c b/mm/slab.c index f7faff7..e6c698f 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2964,11 +2964,10 @@ static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags) struct array_cache *ac; int node; - node = numa_node_id(); - +retry: check_irq_off(); + node = numa_node_id(); ac = cpu_cache_get(cachep); -retry: batchcount = ac->batchcount; if (!ac->touched && batchcount > BATCHREFILL_LIMIT) { /*
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