From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id 7F7A16B004D for ; Tue, 19 May 2009 21:07:42 -0400 (EDT) Received: from m2.gw.fujitsu.co.jp ([10.0.50.72]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n4K17lTW021449 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Wed, 20 May 2009 10:07:47 +0900 Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 0D4F445DD79 for ; Wed, 20 May 2009 10:07:47 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (s2.gw.fujitsu.co.jp [10.0.50.92]) by m2.gw.fujitsu.co.jp (Postfix) with ESMTP id E398E45DE51 for ; Wed, 20 May 2009 10:07:46 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id C87D4E18001 for ; Wed, 20 May 2009 10:07:46 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.249.87.104]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 7FEA1E38001 for ; Wed, 20 May 2009 10:07:46 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH] readahead:add blk_run_backing_dev In-Reply-To: <6.0.0.20.2.20090518183752.0581fdc0@172.19.0.2> References: <6.0.0.20.2.20090518183752.0581fdc0@172.19.0.2> Message-Id: <20090520100602.7438.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Wed, 20 May 2009 10:07:45 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Hisashi Hifumi Cc: kosaki.motohiro@jp.fujitsu.com, Andrew Morton , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm , Wu Fengguang List-ID: (cc to Wu and linux-mm) > Hi. > > I wrote a patch that adds blk_run_backing_dev on page_cache_async_readahead > so readahead I/O is unpluged to improve throughput. > > Following is the test result with dd. > > #dd if=testdir/testfile of=/dev/null bs=16384 > > -2.6.30-rc6 > 1048576+0 records in > 1048576+0 records out > 17179869184 bytes (17 GB) copied, 224.182 seconds, 76.6 MB/s > > -2.6.30-rc6-patched > 1048576+0 records in > 1048576+0 records out > 17179869184 bytes (17 GB) copied, 206.465 seconds, 83.2 MB/s > > Sequential read performance on a big file was improved. > Please merge my patch. I guess the improvement depend on readahead window size. Have you mesure random access workload? > > Thanks. > > Signed-off-by: Hisashi Hifumi > > diff -Nrup linux-2.6.30-rc6.org/mm/readahead.c linux-2.6.30-rc6.unplug/mm/readahead.c > --- linux-2.6.30-rc6.org/mm/readahead.c 2009-05-18 10:46:15.000000000 +0900 > +++ linux-2.6.30-rc6.unplug/mm/readahead.c 2009-05-18 13:00:42.000000000 +0900 > @@ -490,5 +490,7 @@ page_cache_async_readahead(struct addres > > /* do read-ahead */ > ondemand_readahead(mapping, ra, filp, true, offset, req_size); > + > + blk_run_backing_dev(mapping->backing_dev_info, NULL); > } > EXPORT_SYMBOL_GPL(page_cache_async_readahead); > > -- > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org