Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751125AbVLLIuX (ORCPT ); Mon, 12 Dec 2005 03:50:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751138AbVLLIuX (ORCPT ); Mon, 12 Dec 2005 03:50:23 -0500 Received: from gw1.cosmosbay.com ([62.23.185.226]:17025 "EHLO gw1.cosmosbay.com") by vger.kernel.org with ESMTP id S1751125AbVLLIuW (ORCPT ); Mon, 12 Dec 2005 03:50:22 -0500 Message-ID: <439D39A8.1020806@cosmosbay.com> Date: Mon, 12 Dec 2005 09:49:44 +0100 From: Eric Dumazet User-Agent: Mozilla Thunderbird 1.0 (Windows/20041206) X-Accept-Language: fr, en MIME-Version: 1.0 To: Paul Jackson CC: akpm@osdl.org, linux-kernel@vger.kernel.org, Nick Piggin , Simon Derr , Andi Kleen , Christoph Lameter Subject: Re: [PATCH] Cpuset: rcu optimization of page alloc hook References: <20051211233130.18000.2748.sendpatchset@jackhammer.engr.sgi.com> In-Reply-To: <20051211233130.18000.2748.sendpatchset@jackhammer.engr.sgi.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-1.6 (gw1.cosmosbay.com [172.16.8.80]); Mon, 12 Dec 2005 09:49:45 +0100 (CET) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 644 Lines: 22 Paul Jackson a ?crit : > + > +static kmem_cache_t *cpuset_cache; > + Hi Paul Please do use __read_mostly for new kmem_cache : static kmem_cache_t *cpuset_cache __read_mostly; If not, the pointer can sit in the midle of a highly modified cache line, and multiple CPUS will have memory cache misses to access the cpuset_cache, while slab code/data layout itself is very NUMA/SMP friendly. Eric - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/