From: Gerd Bavendiek Subject: Re: Differences between 2.6.5 und 2.6.16: getattr with actimeo=0 and O_DIRECT Date: Tue, 13 Nov 2007 16:55:45 +0100 Message-ID: <4739C901.1020404@googlemail.com> References: <4739686E.8080501@googlemail.com> <1194960598.7468.11.camel@heimdal.trondhjem.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: nfs@lists.sourceforge.net To: Trond Myklebust Return-path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list2-new.sourceforge.net with esmtp (Exim 4.43) id 1Iry7C-0006TP-LK for nfs@lists.sourceforge.net; Tue, 13 Nov 2007 07:55:50 -0800 Received: from mu-out-0910.google.com ([209.85.134.184]) by mail.sourceforge.net with esmtp (Exim 4.44) id 1Iry7H-0001fD-W7 for nfs@lists.sourceforge.net; Tue, 13 Nov 2007 07:55:56 -0800 Received: by mu-out-0910.google.com with SMTP id i2so2699201mue for ; Tue, 13 Nov 2007 07:55:53 -0800 (PST) In-Reply-To: <1194960598.7468.11.camel@heimdal.trondhjem.org> List-Id: "Discussion of NFS under Linux development, interoperability, and testing." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: nfs-bounces@lists.sourceforge.net Errors-To: nfs-bounces@lists.sourceforge.net Trond Myklebust schrieb: > On Tue, 2007-11-13 at 10:03 +0100, Gerd Bavendiek wrote: >> Hi, >> >> analyzing performance issues with Oracle databases on an NFS client >> running on SLES9 SP3 and NetApp as NFS server, I found that in SLES9 >> SP3 each write call is followed by an getattr. This is not the case >> with SLES10 SP1. >> >> Mount options in use are: >> >> rw,v3,rsize=32768,wsize=32768,acregmin=0,acregmax=0,acdirmin=0,acdirmax=0,hard,lock,proto=tcp,addr=172.18.131.134 >> >> I do >> >> dd if=/dev/zero of=/mnt/qqq oflag=direct bs=8k count=100000 >> >> and using tcpdump (BTW, is there an easier way ?) I see with SLES9 SP3 >> (i.e. 2.6.5-7.244) each single 8k write followed by an getattr (which >> comes at some cost). >> >> Using SLES10 SP1 (2.6.16.46-0.12) there is only one getattr when dd >> closes the file. >> >> Is there anything I can do to avoid the getattr calls in SLES9 SP3 >> (no, sorry, can't update to SLES10 SP1) ? > > For one thing, you could turn attribute caching back on. I don't know > why SLES10 fails to GETATTR, but acregmin=0,acregmax=0 turns attribute > caching off. Append writes need to know where the end-of-file is, and so > they will force a GETATTR when there is no attribute caching. > > Trond > > Trond, you say: SLES10 fails to GETATTR. So with acregmin=0,acregmax=0 etc. we should always have one write AND one getattr ? So SLES9 SP3 does it the right way ? Gerd ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs