From mboxrd@z Thu Jan 1 00:00:00 1970 From: Trond Myklebust Subject: Re: [PATCH 06/43] FS-Cache: Recruit a couple of page flags for cache management [ver #46] Date: Thu, 02 Apr 2009 15:19:47 -0400 Message-ID: <1238699987.16087.26.camel@heimdal.trondhjem.org> References: <200904030431.04079.nickpiggin@yahoo.com.au> <200904030353.17713.nickpiggin@yahoo.com.au> <200904030315.03606.nickpiggin@yahoo.com.au> <7249.1238692155@redhat.com> <7516.1238694057@redhat.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Nick Piggin , viro@zeniv.linux.org.uk, nfsv4@linux-nfs.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org To: David Howells Return-path: Received: from mail-out2.uio.no ([129.240.10.58]:53791 "EHLO mail-out2.uio.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1764980AbZDBTUT (ORCPT ); Thu, 2 Apr 2009 15:20:19 -0400 In-Reply-To: <7516.1238694057@redhat.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Thu, 2009-04-02 at 18:40 +0100, David Howells wrote: > Nick Piggin wrote: > > > Well in theory I still think it would be cleanest to modify buffer to > > play more nicely with it. But maybe that ends up being harder to > > distinguish the 3 cases of attached metadata on the page. I don't know, > > you haven't posted any isofs code so either way it is inappropriate to > > use up this extra page flag here. > > > > Is isofs cache worth a page flag? > > Well, isofs was something I wanted at the time. > > Besides, as I said NFS uses PG_private for its own purposes, and entangling > the two wasn't the most fun I've had. Trond didn't like it either. We use it for exactly the same purpose as everyone else: to signal that we need a callback to ->releasepage() if the VM wants to truncate the page. Trond