From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: RFC: always use REQ_OP_WRITE_ZEROES for zeroing offload Date: Mon, 27 Mar 2017 02:10:56 -0700 Message-ID: <20170327091056.GB6879@infradead.org> References: <20170323143341.31549-1-hch@lst.de> <20170323155410.GD1138@soda.linbit> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20170323155410.GD1138-w1SgEEioFePxa46PmUWvFg@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: drbd-dev-bounces-cunTk1MwBs8qoQakbn7OcQ@public.gmane.org Errors-To: drbd-dev-bounces-cunTk1MwBs8qoQakbn7OcQ@public.gmane.org To: Christoph Hellwig , axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org, martin.petersen-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org, agk-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, snitzer-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, shli-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, philipp.reisner-63ez5xqkn6DQT0dZR+AlfA@public.gmane.org, linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, drbd-dev-cunTk1MwBs8qoQakbn7OcQ@public.gmane.org, dm-devel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, linux-raid-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-raid.ids It sounds like you don't want to support traditional discard at all, but only WRITE ZEROES. So in many ways this series is the right way forward. It would be nice if we could do a full blown REQ_OP_WRITE_ZEROES for dm_think that zeroes out partial blocks, similar to what hardware that implements WRITE SAME of zeroes or WRITE ZEROES would do. I'll see if I could include that in my series. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Mon, 27 Mar 2017 02:10:56 -0700 From: Christoph Hellwig To: Christoph Hellwig , axboe@kernel.dk, martin.petersen@oracle.com, agk@redhat.com, snitzer@redhat.com, shli@kernel.org, philipp.reisner@linbit.com, linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, drbd-dev@lists.linbit.com, dm-devel@redhat.com, linux-raid@vger.kernel.org Subject: Re: RFC: always use REQ_OP_WRITE_ZEROES for zeroing offload Message-ID: <20170327091056.GB6879@infradead.org> References: <20170323143341.31549-1-hch@lst.de> <20170323155410.GD1138@soda.linbit> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20170323155410.GD1138@soda.linbit> List-ID: It sounds like you don't want to support traditional discard at all, but only WRITE ZEROES. So in many ways this series is the right way forward. It would be nice if we could do a full blown REQ_OP_WRITE_ZEROES for dm_think that zeroes out partial blocks, similar to what hardware that implements WRITE SAME of zeroes or WRITE ZEROES would do. I'll see if I could include that in my series.