From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752509Ab1IUPfv (ORCPT ); Wed, 21 Sep 2011 11:35:51 -0400 Received: from rcsinet15.oracle.com ([148.87.113.117]:28285 "EHLO rcsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752494Ab1IUPft (ORCPT ); Wed, 21 Sep 2011 11:35:49 -0400 Date: Wed, 21 Sep 2011 11:35:37 -0400 From: Konrad Rzeszutek Wilk To: Christoph Hellwig Cc: axboe@kernel.dk, linux-kernel@vger.kernel.org, jaxboe@fusionio.com, lidongyang@novell.com, joe.jin@oracle.com Subject: Re: [GIT PULL] (xen) stable/for-jens-3.2 - blkback and blkfront patches for 3.2 Message-ID: <20110921153537.GB1512@phenom.oracle.com> References: <20110921150955.GH541@phenom.oracle.com> <20110921151732.GA28043@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110921151732.GA28043@infradead.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: rtcsinet21.oracle.com [66.248.204.29] X-CT-RefId: str=0001.0A090205.4E7A044D.0204,ss=1,re=0.000,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 21, 2011 at 11:17:32AM -0400, Christoph Hellwig wrote: > On Wed, Sep 21, 2011 at 11:09:55AM -0400, Konrad Rzeszutek Wilk wrote: > > Hey Jens, > > > > Please pull the following git tree in your 3.2 drivers tree: > > > > git pull git://oss.oracle.com/git/kwilk/xen.git stable/for-jens-3.2 > > > > which has an exciting new feature - the discard ('feature-discard') > > aka TRIM/UNMAP. Now they can be passed from the guest to the backend. > > What is the design of them? Do you provide the 'discard zeroes data' > flag (mandatory for any kind of relible operation) and 'discard Hmm, not sure what that is. Is that REQ_SECURE, err BLKDEV_DISCARD_SECURE? If so then not in this patchset - but it does not seem like it would dificult to add that in? Li, what do you think? > granularity / alignment' tunables (very useful)? The discard granularity/alignment are certainly there. But they are just one way (backend tells the guest what they are). Should they be more tunable (frontend tells the backend what the values ought to be?) Li, did I miss anything in my response?