From: Boaz Harrosh Subject: Re: [PATCH] pnfsblock: Lookup list entry of layouts and tags in reverse order Date: Mon, 17 May 2010 17:24:39 +0300 Message-ID: <4BF151A7.1070003@panasas.com> References: <20100510033610.GA5443@MDS-78.localdomain> <4BEA4ED3.3010702@panasas.com> <20100512202811.GA9296@fieldses.org> <20100517135341.GA30737@fieldses.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: Benny Halevy , Zhang Jingwang , linux-nfs@vger.kernel.org, iisaman@netapp.com To: "J. Bruce Fields" Return-path: Received: from mail-wy0-f174.google.com ([74.125.82.174]:37398 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751441Ab0EQOYq (ORCPT ); Mon, 17 May 2010 10:24:46 -0400 Received: by wyb39 with SMTP id 39so477647wyb.19 for ; Mon, 17 May 2010 07:24:44 -0700 (PDT) In-Reply-To: <20100517135341.GA30737@fieldses.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: On 05/17/2010 04:53 PM, J. Bruce Fields wrote: > On Wed, May 12, 2010 at 04:28:12PM -0400, bfields wrote: >> On Wed, May 12, 2010 at 09:46:43AM +0300, Benny Halevy wrote: >>> On May. 10, 2010, 6:36 +0300, Zhang Jingwang wrote: >>>> Optimize for sequencial write. Layout infos and tags are organized by >>>> file offset. When appending data to a file whole list will be examined, >>>> which introduce notable performance decrease. >>> >>> Looks good to me. >>> >>> Fred, can you please double check? >> >> I don't know if Fred's still up for reviewing block stuff? >> >> I've been trying to keep up with at least some minimal testing, but not >> as well as I'd like. >> >> The one thing I've noticed is that the connectathon general test has >> started failing right at the start with an IO error. The last good >> version I tested was b5c09c21, which was based on 33-rc6. The earliest >> bad version I tested was 419312ada, based on 34-rc2. A quick look at >> network traces from the two traces didn't turn up anything obvious. I >> haven't had the chance yet to look closer. > > As of the latest (6666f47d), in my tests the client is falling back on > IO to the MDS and doing no block IO at all. b5c09c21 still works, so > the problem isn't due to a change in the server I'm testing against. I > haven't investigated any more closely. > You might be hitting the .commit bug, no? Still no fix. I'm using a work around for objects. I'm not sure how it affects blocks. I think you should see that the very first IO goes through layout driver then the IO is redone through MDS, for each node. Even though write/read returned success because commit returns NOT_ATTEMPTED. But I might be totally off. Boaz > --b. > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >