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| author | Joe Korty <joe.korty@ccur.com> | 2008-03-05 15:04:59 -0800 |
|---|---|---|
| committer | Christoph Lameter <clameter@sgi.com> | 2008-03-06 16:21:50 -0800 |
| commit | 6d2144d355d2a532e5cc3fc12a6ba2a8d4ef15e4 (patch) | |
| tree | 1c27eecfce86a166ca827bfbd2fe7a46888a7bc0 | |
| parent | b6210386787728b84db25adc4f1eba70440a4c73 (diff) | |
| download | linux-6d2144d355d2a532e5cc3fc12a6ba2a8d4ef15e4.tar.bz2 | |
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>
| -rw-r--r-- | mm/slab.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/mm/slab.c b/mm/slab.c index f7faff72cf56..e6c698f55674 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) { /* |