Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934636AbXLPMHC (ORCPT ); Sun, 16 Dec 2007 07:07:02 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934125AbXLPMEe (ORCPT ); Sun, 16 Dec 2007 07:04:34 -0500 Received: from smtp.ustc.edu.cn ([202.38.64.16]:60612 "HELO ustc.edu.cn" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with SMTP id S934083AbXLPME0 (ORCPT ); Sun, 16 Dec 2007 07:04:26 -0500 Message-ID: <397806668.82846@ustc.edu.cn> X-EYOUMAIL-SMTPAUTH: wfg@mail.ustc.edu.cn Message-Id: <20071216120418.055796608@mail.ustc.edu.cn> References: <20071216115927.986126305@mail.ustc.edu.cn> User-Agent: quilt/0.46-1 Date: Sun, 16 Dec 2007 19:59:32 +0800 From: Fengguang Wu To: Andrew Morton Cc: Linus Torvalds Cc: linux-kernel@vger.kernel.org Subject: [PATCH 4/9] readahead: quick startup on sequential mmap readahead Content-Disposition: inline; filename=readahead-sequential-quick-start.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1096 Lines: 30 When the user explicitly sets MADV_SEQUENTIAL, we should really avoid the slow readahead size ramp-up phase and start full-size readahead immediately. This patch won't change behavior for the auto-detected sequential mmap reads. Its previous read-around size is ra_pages/2, so it will be doubled to the full readahead size anyway. Signed-off-by: Fengguang Wu --- mm/filemap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- linux-2.6.24-rc4-mm1.orig/mm/filemap.c +++ linux-2.6.24-rc4-mm1/mm/filemap.c @@ -1320,7 +1320,7 @@ static void do_sync_mmap_readahead(struc if (VM_SequentialReadHint(vma) || offset - 1 == (ra->prev_pos >> PAGE_CACHE_SHIFT)) { - page_cache_sync_readahead(mapping, ra, file, offset, 1); + page_cache_sync_readahead(mapping, ra, file, offset, ra->ra_pages); return; } -- -- 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/