From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752651Ab1IVQgu (ORCPT ); Thu, 22 Sep 2011 12:36:50 -0400 Received: from rcsinet15.oracle.com ([148.87.113.117]:22838 "EHLO rcsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751886Ab1IVQgt (ORCPT ); Thu, 22 Sep 2011 12:36:49 -0400 Date: Thu, 22 Sep 2011 11:54:49 -0400 From: Konrad Rzeszutek Wilk To: Li Dongyang Cc: Christoph Hellwig , "axboe@kernel.dk" , "linux-kernel@vger.kernel.org" , "jaxboe@fusionio.com" , "joe.jin@oracle.com" Subject: Re: [GIT PULL] (xen) stable/for-jens-3.2 - blkback and blkfront patches for 3.2 Message-ID: <20110922155449.GA16401@phenom.oracle.com> References: <20110921150955.GH541@phenom.oracle.com> <20110921151732.GA28043@infradead.org> <20110921153537.GB1512@phenom.oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: acsinet22.oracle.com [141.146.126.238] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090204.4E7B6416.01C0:SCFMA922111,ss=1,re=-4.000,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 22, 2011 at 09:05:17PM +1000, Li Dongyang wrote: > On Thursday, September 22, 2011, Konrad Rzeszutek Wilk < > konrad.wilk@oracle.com> wrote: > > 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? > We deal the discard with 2 ways in the backend depend on what the guest is > using: > punch the hole on the image, to save some disk usage, > or redirect the discard request to phy device. > for the hole punching case, we are already DISCARD_SECURE, > for the phy dev case, we could add the flag and pass it from blkfront to > blkback, and yes > That's not difficult, could be added later. Li, could you implement it please - on top of the 'stable/for-jens-3.2' patch queue ? If it would not be too much trouble of course. > > > >> 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?) > > > Yes, plz tell more about tunable granularity and alignment, and we can add > that later, > Thanks a lot > > Li, did I miss anything in my response? > >