From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46860) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WAMSy-0002gv-UU for qemu-devel@nongnu.org; Mon, 03 Feb 2014 11:33:49 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WAMSy-0004iq-3L for qemu-devel@nongnu.org; Mon, 03 Feb 2014 11:33:48 -0500 Received: from mo6-p00-ob.smtp.rzone.de ([2a01:238:20a:202:5300::3]:18214) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WAMSx-0004iP-Q3 for qemu-devel@nongnu.org; Mon, 03 Feb 2014 11:33:48 -0500 Date: Mon, 3 Feb 2014 17:03:25 +0100 From: Olaf Hering Message-ID: <20140203160325.GA29813@aepfle.de> References: <1391094138-26798-1-git-send-email-olaf@aepfle.de> <20140203154908.GO3643@dhcp-200-207.str.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20140203154908.GO3643@dhcp-200-207.str.redhat.com> Subject: Re: [Qemu-devel] [PATCH] xen_disk: add discard support List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf Cc: qemu-devel@nongnu.org, stefanha@redhat.com, stefano.stabellini@eu.citrix.com On Mon, Feb 03, Kevin Wolf wrote: > Am 30.01.2014 um 16:02 hat Olaf Hering geschrieben: > > + case BLKIF_OP_DISCARD: > > + { > > + struct blkif_request_discard *discard_req = (void *)&ioreq->req; > > + bdrv_acct_start(blkdev->bs, &ioreq->acct, > > + discard_req->nr_sectors * BLOCK_SIZE, BDRV_ACCT_WRITE); > > Neither SCSI nor IDE account for discards. I think we should keep the > behaviour consistent across devices. > > If we do want to introduce accounting for discards, I'm not sure whether > counting them as writes or giving them their own category makes more > sense. This line was just copied. I have to look how virtio does it, maybe I copied it from there. No problem with removing it from my side. But I think in the end a discard is also a write, isnt it? Olaf