Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753425AbYLTGF6 (ORCPT ); Sat, 20 Dec 2008 01:05:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751980AbYLTGFt (ORCPT ); Sat, 20 Dec 2008 01:05:49 -0500 Received: from mx2.netapp.com ([216.240.18.37]:3622 "EHLO mx2.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750936AbYLTGFs convert rfc822-to-8bit (ORCPT ); Sat, 20 Dec 2008 01:05:48 -0500 X-IronPort-AV: E=Sophos;i="4.36,253,1228118400"; d="scan'208";a="101061253" X-MimeOLE: Produced By Microsoft Exchange V6.5 Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Subject: RE: Pull request for FS-Cache, including NFS patches Date: Fri, 19 Dec 2008 22:05:38 -0800 Message-ID: <7A24DF798E223B4C9864E8F92E8C93EC01AAF709@SACMVEXC1-PRD.hq.netapp.com> In-Reply-To: <13180.1229736005@redhat.com> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: Pull request for FS-Cache, including NFS patches Thread-Index: AcliQSPaPvtPeDn3SJeSfvzUq+HsIQAJ324w From: "Muntz, Daniel" To: "David Howells" , "Bryan Henderson" Cc: "Andrew Morton" , , , , , , X-OriginalArrivalTime: 20 Dec 2008 06:05:45.0669 (UTC) FILETIME=[FF559750:01C96268] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1362 Lines: 37 Callbacks, instead of assuming your data is good for some short period of time. It's all well and good that there are mechanisms to know that data has changed, but without some leasing/callback/(ugh)mandatory locking, you're just estimating consistency. -Dan -----Original Message----- From: David Howells [mailto:dhowells@redhat.com] Sent: Friday, December 19, 2008 5:20 PM To: Bryan Henderson Cc: dhowells@redhat.com; Andrew Morton; Muntz, Daniel; linux-fsdevel@vger.kernel.org; linux-kernel@vger.kernel.org; nfsv4@linux-nfs.org; rwheeler@redhat.com; sfr@canb.auug.org.au; steved@redhat.com Subject: Re: Pull request for FS-Cache, including NFS patches Bryan Henderson wrote: > > > AFS was designed to support local disk cache, so with callbacks > > > you can get a consistent system. > > > > It's less the callbacks and more the data version number that's important. > > Maybe for consistency, but for the performance benefits of local disk > caching, I believe the callbacks are pretty important. Indeed, but he said "so with callbacks you can get a _consistent_ system". David -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/