From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751253AbWFYNJj (ORCPT ); Sun, 25 Jun 2006 09:09:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751257AbWFYNJV (ORCPT ); Sun, 25 Jun 2006 09:09:21 -0400 Received: from smtp.ustc.edu.cn ([202.38.64.16]:19166 "HELO ustc.edu.cn") by vger.kernel.org with SMTP id S1751419AbWFYNJQ (ORCPT ); Sun, 25 Jun 2006 09:09:16 -0400 Message-ID: <351240953.20240@ustc.edu.cn> X-EYOUMAIL-SMTPAUTH: wfg@mail.ustc.edu.cn Message-Id: <20060625130923.154258797@localhost.localdomain> References: <20060625130704.464870100@localhost.localdomain> Date: Sun, 25 Jun 2006 21:07:10 +0800 From: Wu Fengguang To: Andrew Morton Cc: linux-kernel@vger.kernel.org, Wu Fengguang Subject: [PATCH 6/6] readahead: remove the size limit of max_sectors_kb on read_ahead_kb Content-Disposition: inline; filename=readahead-size-limited-by-max-sectors-fix.patch Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Remove the corelation between max_sectors_kb and read_ahead_kb. It's unnecessary to reduce readahead size when setting max_sectors_kb. Signed-off-by: Wu Fengguang --- --- linux-2.6.17-mm2.orig/block/ll_rw_blk.c +++ linux-2.6.17-mm2/block/ll_rw_blk.c @@ -3851,25 +3851,11 @@ queue_max_sectors_store(struct request_q max_hw_sectors_kb = q->max_hw_sectors >> 1, page_kb = 1 << (PAGE_CACHE_SHIFT - 10); ssize_t ret = queue_var_store(&max_sectors_kb, page, count); - int ra_kb; if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb) return -EINVAL; - /* - * Take the queue lock to update the readahead and max_sectors - * values synchronously: - */ - spin_lock_irq(q->queue_lock); - /* - * Trim readahead window as well, if necessary: - */ - ra_kb = q->backing_dev_info.ra_pages << (PAGE_CACHE_SHIFT - 10); - if (ra_kb > max_sectors_kb) - q->backing_dev_info.ra_pages = - max_sectors_kb >> (PAGE_CACHE_SHIFT - 10); q->max_sectors = max_sectors_kb << 1; - spin_unlock_irq(q->queue_lock); return ret; } --