From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756525Ab0BBPfm (ORCPT ); Tue, 2 Feb 2010 10:35:42 -0500 Received: from mga09.intel.com ([134.134.136.24]:14323 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756377Ab0BBPeQ (ORCPT ); Tue, 2 Feb 2010 10:34:16 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.49,390,1262592000"; d="scan'208";a="592471018" Message-Id: <20100202153316.513043033@intel.com> User-Agent: quilt/0.48-1 Date: Tue, 02 Feb 2010 23:28:37 +0800 From: Wu Fengguang To: Andrew Morton cc: Jens Axboe , Peter Zijlstra , Martin Schwidefsky , Christian Ehrhardt , Wu Fengguang cc: Linux Memory Management List cc: Cc: LKML Subject: [PATCH 02/11] readahead: bump up the default readahead size References: <20100202152835.683907822@intel.com> Content-Disposition: inline; filename=readahead-enlarge-default-size.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Use 512kb max readahead size, and 32kb min readahead size. The former helps io performance for common workloads. The latter will be used in the thrashing safe context readahead. CC: Jens Axboe CC: Peter Zijlstra CC: Martin Schwidefsky CC: Christian Ehrhardt Signed-off-by: Wu Fengguang --- include/linux/mm.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- linux.orig/include/linux/mm.h 2010-01-30 17:38:49.000000000 +0800 +++ linux/include/linux/mm.h 2010-01-30 18:09:58.000000000 +0800 @@ -1184,8 +1184,8 @@ int write_one_page(struct page *page, in void task_dirty_inc(struct task_struct *tsk); /* readahead.c */ -#define VM_MAX_READAHEAD 128 /* kbytes */ -#define VM_MIN_READAHEAD 16 /* kbytes (includes current page) */ +#define VM_MAX_READAHEAD 512 /* kbytes */ +#define VM_MIN_READAHEAD 32 /* kbytes (includes current page) */ int force_page_cache_readahead(struct address_space *mapping, struct file *filp, pgoff_t offset, unsigned long nr_to_read);