From: Amit Gud Subject: Re: [PATCH] NFS: Add acreg{min,max} and acdir{min,max} in milliseconds Date: Fri, 12 Jun 2009 14:49:17 -0700 Message-ID: <4A32CD5D.2070502@akamai.com> References: <200906091832.50633.agud@akamai.com> <1244636844.24750.23.camel@heimdal.trondhjem.org> <4A300CE3.8080502@akamai.com> <025BEFCD-2F56-4E29-99F9-1939867B48A7@fys.uio.no> <4A316814.7030609@akamai.com> <1244754888.5047.132.camel@heimdal.trondhjem.org> <4A32ACDB.90802@akamai.com> <1244836259.19533.19.camel@heimdal.trondhjem.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: "linux-nfs@vger.kernel.org" , Steve Dickson , "gud-OYTqUY/oFF8@public.gmane.org" , "Uhlenkott, Jason" To: Trond Myklebust Return-path: Received: from prod-mail-xrelay03.akamai.com ([96.6.114.84]:39346 "EHLO prod-mail-xrelay03.akamai.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755711AbZFLVsz (ORCPT ); Fri, 12 Jun 2009 17:48:55 -0400 In-Reply-To: <1244836259.19533.19.camel-rJ7iovZKK19ZJLDQqaL3InhyD016LWXt@public.gmane.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: Trond Myklebust wrote: > On Fri, 2009-06-12 at 12:30 -0700, Amit Gud wrote: >> We definitely want lookup caching turned on, always, including both >> positive and negative caching. But, we need to see new files, unlinks, >> and renames much quicker than a second. > > Then use the lookupcache option, since that's what it is for. > Sorry, I don't understand. Copying from your last mail: > Secondly, we have already introduced finer control over the lookup > caching as of Linux 2.6.28 and newer: > - if you want to ensure that machine A always see new files and > links immediately once they have been created, then > '-olookupcache=positive' should turn off negative dentry > caching. > - if you also want to ensure that it immediately sees renames, > unlinks and such, then '-olookupcache=none' will turn off lookup > caching altogether. How is it possible to _not_ disable any caching (positive or negative dentries) and still be able to see renames, unlinks and such in << 1s? AG -- May the source be with you. http://www.cis.ksu.edu/~gud