From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752253AbaEVTZe (ORCPT ); Thu, 22 May 2014 15:25:34 -0400 Received: from qmta02.emeryville.ca.mail.comcast.net ([76.96.30.24]:60262 "EHLO qmta02.emeryville.ca.mail.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750870AbaEVTZd (ORCPT ); Thu, 22 May 2014 15:25:33 -0400 Date: Thu, 22 May 2014 14:25:30 -0500 (CDT) From: Christoph Lameter To: Vladimir Davydov cc: hannes@cmpxchg.org, mhocko@suse.cz, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH RFC 3/3] slub: reparent memcg caches' slabs on memcg offline In-Reply-To: <20140522134726.GA3147@esperanza> Message-ID: References: <20140515071650.GB32113@esperanza> <20140516132234.GF32113@esperanza> <20140519152437.GB25889@esperanza> <537A4D27.1050909@parallels.com> <20140521150408.GB23193@esperanza> <20140522134726.GA3147@esperanza> Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 22 May 2014, Vladimir Davydov wrote: > On Wed, May 21, 2014 at 07:13:21PM -0500, Christoph Lameter wrote: > > On Wed, 21 May 2014, Vladimir Davydov wrote: > > > > > Do I understand you correctly that the following change looks OK to you? > > > > Almost. Preemption needs to be enabled before functions that invoke the > > page allocator etc etc. > > I need to disable preemption only in slab_free, which never blocks > according to its semantics, so everything should be fine just like that. slab_free calls __slab_free which can release slabs via put_cpu_partial()/unfreeze_partials()/discard_slab() to the page allocator. I'd rather have preemption enabled there.