diff options
author | Ravikiran G Thirumalai <kiran@scalex86.org> | 2006-02-04 23:27:59 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-02-05 11:06:53 -0800 |
commit | 4484ebf12bdb0ebcdc6e8951243cbab3d7f6f4c1 (patch) | |
tree | 9feabea0bac1e6401742bc95bf381e36d2651fbc /arch/frv | |
parent | ca3b9b91735316f0ec7f01976f85842e0bfe5c6e (diff) | |
download | op-kernel-dev-4484ebf12bdb0ebcdc6e8951243cbab3d7f6f4c1.zip op-kernel-dev-4484ebf12bdb0ebcdc6e8951243cbab3d7f6f4c1.tar.gz |
[PATCH] NUMA slab locking fixes: fix cpu down and up locking
This fixes locking and bugs in cpu_down and cpu_up paths of the NUMA slab
allocator. Sonny Rao <sonny@burdell.org> reported problems sometime back on
POWER5 boxes, when the last cpu on the nodes were being offlined. We could
not reproduce the same on x86_64 because the cpumask (node_to_cpumask) was not
being updated on cpu down. Since that issue is now fixed, we can reproduce
Sonny's problems on x86_64 NUMA, and here is the fix.
The problem earlier was on CPU_DOWN, if it was the last cpu on the node to go
down, the array_caches (shared, alien) and the kmem_list3 of the node were
being freed (kfree) with the kmem_list3 lock held. If the l3 or the
array_caches were to come from the same cache being cleared, we hit on
badness.
This patch cleans up the locking in cpu_up and cpu_down path. We cannot
really free l3 on cpu down because, there is no node offlining yet and even
though a cpu is not yet up, node local memory can be allocated for it. So l3s
are usually allocated at keme_cache_create and destroyed at
kmem_cache_destroy. Hence, we don't need cachep->spinlock protection to get
to the cachep->nodelist[nodeid] either.
Patch survived onlining and offlining on a 4 core 2 node Tyan box with a 4
dbench process running all the time.
Signed-off-by: Alok N Kataria <alokk@calsoftinc.com>
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: Christoph Lameter <christoph@lameter.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/frv')
0 files changed, 0 insertions, 0 deletions