From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932985Ab3LDQqJ (ORCPT ); Wed, 4 Dec 2013 11:46:09 -0500 Received: from a9-50.smtp-out.amazonses.com ([54.240.9.50]:55450 "EHLO a9-50.smtp-out.amazonses.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932508Ab3LDQqG (ORCPT ); Wed, 4 Dec 2013 11:46:06 -0500 X-Greylist: delayed 741 seconds by postgrey-1.27 at vger.kernel.org; Wed, 04 Dec 2013 11:46:06 EST Date: Wed, 4 Dec 2013 16:33:43 +0000 From: Christoph Lameter X-X-Sender: cl@gentwo.org To: Joonsoo Kim cc: Andrew Morton , Joonsoo Kim , Johannes Weiner , Michal Hocko , azurIt , Linux Memory Management List , cgroups@vger.kernel.org, LKML , Christian Casteyde , Pekka Enberg Subject: Re: [patch 2/2] fs: buffer: move allocation failure loop into the allocator In-Reply-To: Message-ID: <00000142be753b07-aa0e2354-6704-41f8-8e11-3c856a186af5-000000@email.amazonses.com> References: <1381265890-11333-1-git-send-email-hannes@cmpxchg.org> <1381265890-11333-2-git-send-email-hannes@cmpxchg.org> <20131203165910.54d6b4724a1f3e329af52ac6@linux-foundation.org> <20131204015218.GA19709@lge.com> <20131203180717.94c013d1.akpm@linux-foundation.org> <00000142be2f1de0-764bb035-adbc-4367-b2b4-bf05498510a6-000000@email.amazonses.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-SES-Outgoing: 2013.12.04-54.240.9.50 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 5 Dec 2013, Joonsoo Kim wrote: > Now we have cpu partial slabs facility, so I think that slowpath isn't really > slow. And it doesn't much increase the management overhead in the node > partial lists, because of cpu partial slabs. Well yes that may address some of the issues here. > And larger frame may cause more slab_lock contention or cmpxchg contention > if there are parallel freeings. > > But, I don't know which one is better. Is larger frame still better? :) Could you run some tests to figure this one out? There are also some situations in which we disable the per cpu partial pages though. F.e. for low latency/realtime. I posted in kernel synthetic benchmarks for slab a while back. That maybe something to start with. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Lameter Subject: Re: [patch 2/2] fs: buffer: move allocation failure loop into the allocator Date: Wed, 4 Dec 2013 16:33:43 +0000 Message-ID: <00000142be753b07-aa0e2354-6704-41f8-8e11-3c856a186af5-000000@email.amazonses.com> References: <1381265890-11333-1-git-send-email-hannes@cmpxchg.org> <1381265890-11333-2-git-send-email-hannes@cmpxchg.org> <20131203165910.54d6b4724a1f3e329af52ac6@linux-foundation.org> <20131204015218.GA19709@lge.com> <20131203180717.94c013d1.akpm@linux-foundation.org> <00000142be2f1de0-764bb035-adbc-4367-b2b4-bf05498510a6-000000@email.amazonses.com> Mime-Version: 1.0 Return-path: In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: Content-Type: TEXT/PLAIN; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Joonsoo Kim Cc: Andrew Morton , Joonsoo Kim , Johannes Weiner , Michal Hocko , azurIt , Linux Memory Management List , cgroups@vger.kernel.org, LKML , Christian Casteyde , Pekka Enberg On Thu, 5 Dec 2013, Joonsoo Kim wrote: > Now we have cpu partial slabs facility, so I think that slowpath isn't really > slow. And it doesn't much increase the management overhead in the node > partial lists, because of cpu partial slabs. Well yes that may address some of the issues here. > And larger frame may cause more slab_lock contention or cmpxchg contention > if there are parallel freeings. > > But, I don't know which one is better. Is larger frame still better? :) Could you run some tests to figure this one out? There are also some situations in which we disable the per cpu partial pages though. F.e. for low latency/realtime. I posted in kernel synthetic benchmarks for slab a while back. That maybe something to start with. -- 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