From: Trond Myklebust Subject: Re: [PATCH] Smooth out NFS client writeback Date: Tue, 07 Jun 2005 00:12:23 -0400 Message-ID: <1118117543.13667.28.camel@lade.trondhjem.org> References: <20050602121624.41192.qmail@web30705.mail.mud.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain Cc: nfs@lists.sourceforge.net Return-path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.11] helo=sc8-sf-mx1.sourceforge.net) by sc8-sf-list2.sourceforge.net with esmtp (Exim 4.30) id 1DfVSC-0001Jk-Cc for nfs@lists.sourceforge.net; Mon, 06 Jun 2005 21:12:40 -0700 Received: from pat.uio.no ([129.240.130.16] ident=7411) by sc8-sf-mx1.sourceforge.net with esmtp (TLSv1:AES256-SHA:256) (Exim 4.41) id 1DfVSB-0007Rh-Ie for nfs@lists.sourceforge.net; Mon, 06 Jun 2005 21:12:40 -0700 To: Shantanu Goel In-Reply-To: <20050602121624.41192.qmail@web30705.mail.mud.yahoo.com> Sender: nfs-admin@lists.sourceforge.net Errors-To: nfs-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: Discussion of NFS under Linux development, interoperability, and testing. List-Post: List-Help: List-Subscribe: , List-Archive: to den 02.06.2005 Klokka 05:16 (-0700) skreiv Shantanu Goel: > The low memory situation is avoided because of the > congestion check I added in writepage(). If the inode > is congested, it redirty's the page and returns. It > also issues a commit request if there are at least > NFS_WRITE_CLUSTER pages. This sounds very much like what we were doing in the early 2.6 series when we were returning WRITEPAGE_ACTIVATE in order to achieve the same effect. We ended up reverting those patches after learning that systematically redirtying pages in low-memory situations may lead to some _very_ nasty deadlocks. The above have "works" for ramdisks because they have hard limits on the amount of physical memory they can use in the form of the ramdisk size. NFS OTOH really shouldn't do it, since it has no such limits, and can basically end up eating all of physical memory. Have you BTW tested the performance of the other changes without this part of the patch? I assume the numbers you presented last week were for the combined changes. Cheers, Trond ------------------------------------------------------- This SF.Net email is sponsored by: NEC IT Guy Games. How far can you shotput a projector? How fast can you ride your desk chair down the office luge track? If you want to score the big prize, get to know the little guy. Play to win an NEC 61" plasma display: http://www.necitguy.com/?r=20 _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs