From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936036Ab0BZM4G (ORCPT ); Fri, 26 Feb 2010 07:56:06 -0500 Received: from anchor-post-3.mail.demon.net ([195.173.77.134]:50638 "EHLO anchor-post-3.mail.demon.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935925Ab0BZM4E (ORCPT ); Fri, 26 Feb 2010 07:56:04 -0500 Subject: [PATCH] io: remove padding from io_context on 64bit builds From: Richard Kennedy To: Jens Axboe , Andrew Morton , Nikanth Karthikesan , Jeff Moyer , Vivek Goyal Cc: lkml Content-Type: text/plain; charset="UTF-8" Date: Fri, 26 Feb 2010 12:56:00 +0000 Message-ID: <1267188960.2077.10.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.28.2 (2.28.2-1.fc12) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 64 bit builds when CONFIG_BLK_CGROUP=n (the default) this removes 8 bytes of padding from structure io_context and drops its size from 72 to 64 bytes, so needing one fewer cachelines and allowing more objects per slab in it's kmem_cache. Signed-off-by: Richard Kennedy ---- patch against 2.6.33 compiled & test on x86_64 AMDX2 regards Richard diff --git a/include/linux/iocontext.h b/include/linux/iocontext.h index 78ef023..1195a80 100644 --- a/include/linux/iocontext.h +++ b/include/linux/iocontext.h @@ -49,8 +49,8 @@ struct io_context { /* * For request batching */ - unsigned long last_waited; /* Time last woken after wait for request */ int nr_batch_requests; /* Number of requests left in the batch */ + unsigned long last_waited; /* Time last woken after wait for request */ struct radix_tree_root radix_root; struct hlist_head cic_list;