From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f200.google.com (mail-pf0-f200.google.com [209.85.192.200]) by kanga.kvack.org (Postfix) with ESMTP id C40DF6B0038 for ; Mon, 7 Nov 2016 17:19:21 -0500 (EST) Received: by mail-pf0-f200.google.com with SMTP id i88so56548961pfk.3 for ; Mon, 07 Nov 2016 14:19:21 -0800 (PST) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id n19si4245022pfk.284.2016.11.07.14.19.20 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 07 Nov 2016 14:19:20 -0800 (PST) Date: Mon, 7 Nov 2016 14:19:19 -0800 From: Andrew Morton Subject: Re: [PATCH v3 1/2] memcg: Prevent memcg caches to be both OFF_SLAB & OBJFREELIST_SLAB Message-Id: <20161107141919.fe50cef419918c7a4660f3c2@linux-foundation.org> In-Reply-To: <1478553075-120242-1-git-send-email-thgarnie@google.com> References: <1478553075-120242-1-git-send-email-thgarnie@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Thomas Garnier Cc: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , linux-mm@kvack.org, linux-kernel@vger.kernel.org, gthelen@google.com, vdavydov.dev@gmail.com, mhocko@kernel.org On Mon, 7 Nov 2016 13:11:14 -0800 Thomas Garnier wrote: > 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. Can we please have a better description of the problems which this bug causes? Without this info it's unclear to me which kernel version(s) need the fix. Given that the bug is 6 months old I'm assuming "not very urgent". > 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 This should have had your signed-off-by, as you were on the delivery path. I've made that change. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org