Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752429AbcKGVm1 (ORCPT ); Mon, 7 Nov 2016 16:42:27 -0500 Received: from mail-pf0-f176.google.com ([209.85.192.176]:34904 "EHLO mail-pf0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751670AbcKGVm0 (ORCPT ); Mon, 7 Nov 2016 16:42:26 -0500 From: Thomas Garnier To: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, gthelen@google.com, vdavydov.dev@gmail.com, mhocko@kernel.org Subject: [PATCH v3 1/2] memcg: Prevent memcg caches to be both OFF_SLAB & OBJFREELIST_SLAB Date: Mon, 7 Nov 2016 13:11:14 -0800 Message-Id: <1478553075-120242-1-git-send-email-thgarnie@google.com> X-Mailer: git-send-email 2.8.0.rc3.226.g39d4020 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1556 Lines: 41 From: Greg Thelen While testing OBJFREELIST_SLAB integration with pagealloc, we found a bug where kmem_cache(sys) would be created with both CFLGS_OFF_SLAB & CFLGS_OBJFREELIST_SLAB. The original kmem_cache is created early making OFF_SLAB not possible. When kmem_cache(sys) is created, OFF_SLAB is possible and if pagealloc is enabled it will try to enable it first under certain conditions. Given kmem_cache(sys) reuses the original flag, you can have both flags at the same time resulting in allocation failures and odd behaviors. This fix discards allocator specific flags from memcg before calling create_cache. Fixes: b03a017bebc4 ("mm/slab: introduce new slab management type, OBJFREELIST_SLAB") Signed-off-by: Greg Thelen Tested-by: Thomas Garnier --- Based on next-20161027 --- mm/slab_common.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/slab_common.c b/mm/slab_common.c index 71f0b28..329b038 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -533,8 +533,8 @@ void memcg_create_kmem_cache(struct mem_cgroup *memcg, s = create_cache(cache_name, root_cache->object_size, root_cache->size, root_cache->align, - root_cache->flags, root_cache->ctor, - memcg, root_cache); + root_cache->flags & CACHE_CREATE_MASK, + root_cache->ctor, memcg, root_cache); /* * If we could not create a memcg cache, do not complain, because * that's not critical at all as we can always proceed with the root -- 2.8.0.rc3.226.g39d4020