I think this is a next-only thing. Pekka, can you pick this up, please? --
From: Dave Hansen <[email protected]> The slub code does some setup during early boot in early_kmem_cache_node_alloc() with some local data. There is no possible way that another CPU can see this data, so the slub code doesn't unnecessarily lock it. However, some new lockdep asserts check to make sure that add_partial() _always_ has the list_lock held. Just add the locking, even though it is technically unnecessary. Signed-off-by: Dave Hansen <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: Russell King <[email protected]> --- b/mm/slub.c | 6 ++++++ 1 file changed, 6 insertions(+) diff -puN mm/slub.c~slub-lockdep-workaround mm/slub.c --- a/mm/slub.c~slub-lockdep-workaround 2014-01-24 07:19:23.794069012 -0800 +++ b/mm/slub.c 2014-01-24 07:19:23.799069236 -0800 @@ -2890,7 +2890,13 @@ static void early_kmem_cache_node_alloc( init_kmem_cache_node(n); inc_slabs_node(kmem_cache_node, node, page->objects); + /* + * the lock is for lockdep's sake, not for any actual + * race protection + */ + spin_lock(&n->list_lock); add_partial(n, page, DEACTIVATE_TO_HEAD); + spin_unlock(&n->list_lock); } static void free_kmem_cache_nodes(struct kmem_cache *s) _ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
