[PATCH] mm: fallback_alloc cpuset_zone_allowed irq fix

Paul Jackson
2006-12-06T10:50:03Z

From: Paul Jackson <pj@sgi.com>

fallback_alloc() could end up calling cpuset_zone_allowed()
with interrupts disabled (by code in kmem_cache_alloc_node()),
but without __GFP_HARDWALL set, leading to a possible
call of a sleeping function with interrupts disabled.

This results in the BUG report:

BUG: sleeping function called from invalid context at kernel/cpuset.c:1520
in_atomic():0, irqs_disabled():1

Thanks to Paul Menage for catching this one.

Signed-off-by: Paul Jackson <pj@sgi.com>

---
mm/slab.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletion(-)

--- 2.6.19-rc6-mm2.orig/mm/slab.c 2006-11-30 19:45:50.000000000 -0800
+++ 2.6.19-rc6-mm2/mm/slab.c 2006-12-05 22:41:49.000000000 -0800
@@ -3261,7 +3261,8 @@ void *fallback_alloc(struct kmem_cache *
int nid = zone_to_nid(*z);

if (zone_idx(*z) <= ZONE_NORMAL &&
- cpuset_zone_allowed(*z, flags) &&
+ cpuset_zone_allowed(*z,
+ flags | __GFP_HARDWALL) &&
cache->nodelists[nid])
obj = ____cache_alloc_node(cache,
flags | __GFP_THISNODE, nid);

--
I won't rest till it's the best ...
Programmer, Linux Scalability
Paul Jackson <pj@sgi.com> 1.925.600.0401