commit: 04d94879c8a4973b5499dc26b9d38acee8928791 From: Christoph Lameter <[email protected]> Date: Mon, 10 Jan 2011 10:15:15 -0600 Subject: [PATCH] slub: Avoid use of slub_lock in show_slab_objects()
The purpose of the locking is to prevent removal and additions of nodes when statistics are gathered for a slab cache. So we need to avoid racing with memory hotplug functionality. It is enough to take the memory hotplug locks there instead of the slub_lock. online_pages() currently does not acquire the memory_hotplug lock. Another patch will be submitted by the memory hotplug authors to take the memory hotplug lock and describe the uses of the memory hotplug lock to protect against adding and removal of nodes from non hotplug data structures. Cc: <[email protected]> # 2.6.37 Reported-and-tested-by: Bart Van Assche <[email protected]> Acked-by: David Rientjes <[email protected]> Signed-off-by: Christoph Lameter <[email protected]> Signed-off-by: Pekka Enberg <[email protected]> --- mm/slub.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index bec0e35..96e6907 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -3821,7 +3821,7 @@ static ssize_t show_slab_objects(struct kmem_cache *s, } } - down_read(&slub_lock); + lock_memory_hotplug(); #ifdef CONFIG_SLUB_DEBUG if (flags & SO_ALL) { for_each_node_state(node, N_NORMAL_MEMORY) { @@ -3862,7 +3862,7 @@ static ssize_t show_slab_objects(struct kmem_cache *s, x += sprintf(buf + x, " N%d=%lu", node, nodes[node]); #endif - up_read(&slub_lock); + unlock_memory_hotplug(); kfree(nodes); return x + sprintf(buf + x, "\n"); } _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
