Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755316Ab3HWOYs (ORCPT ); Fri, 23 Aug 2013 10:24:48 -0400 Received: from mail-vc0-f171.google.com ([209.85.220.171]:34698 "EHLO mail-vc0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754543Ab3HWOYq (ORCPT ); Fri, 23 Aug 2013 10:24:46 -0400 MIME-Version: 1.0 In-Reply-To: <00000140ab69e6be-3b2999b6-93b4-4b22-a91f-8929aee5238f-000000@email.amazonses.com> References: <1377161065-30552-1-git-send-email-iamjoonsoo.kim@lge.com> <1377161065-30552-6-git-send-email-iamjoonsoo.kim@lge.com> <00000140a72870a6-f7c87696-ecbc-432c-9f41-93f414c0c623-000000@email.amazonses.com> <20130823065315.GG22605@lge.com> <00000140ab69e6be-3b2999b6-93b4-4b22-a91f-8929aee5238f-000000@email.amazonses.com> Date: Fri, 23 Aug 2013 23:24:45 +0900 Message-ID: Subject: Re: [PATCH 05/16] slab: remove cachep in struct slab_rcu From: JoonSoo Kim To: Christoph Lameter Cc: Joonsoo Kim , Pekka Enberg , Andrew Morton , David Rientjes , Linux Memory Management List , LKML Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1066 Lines: 29 2013/8/23 Christoph Lameter : > On Fri, 23 Aug 2013, Joonsoo Kim wrote: > >> On Thu, Aug 22, 2013 at 05:53:00PM +0000, Christoph Lameter wrote: >> > On Thu, 22 Aug 2013, Joonsoo Kim wrote: >> > >> > > We can get cachep using page in struct slab_rcu, so remove it. >> > >> > Ok but this means that we need to touch struct page. Additional cacheline >> > in cache footprint. >> >> In following patch, we overload RCU_HEAD to LRU of struct page and >> also overload struct slab to struct page. So there is no >> additional cacheline footprint at final stage. > > If you do not use rcu (standard case) then you have an additional > cacheline. > I don't get it. This patch only affect to the rcu case, because it change the code which is in kmem_rcu_free(). It doesn't touch anything in standard case. Thanks. -- 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/