From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46920) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gIXFu-0005qS-LR for qemu-devel@nongnu.org; Fri, 02 Nov 2018 07:04:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gIXFq-0006rd-GJ for qemu-devel@nongnu.org; Fri, 02 Nov 2018 07:04:46 -0400 Date: Fri, 2 Nov 2018 12:04:12 +0100 From: Kevin Wolf Message-ID: <20181102110412.GD7521@dhcp-200-186.str.redhat.com> References: <154115285434.11300.8459925605672823399.stgit@dhcp-3-135.uk.xensource.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <154115285434.11300.8459925605672823399.stgit@dhcp-3-135.uk.xensource.com> Subject: [Qemu-devel] xen_disk qdevification (was: [PATCH 0/3] Performance improvements for xen_disk v2) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Tim Smith Cc: xen-devel@lists.xenproject.org, qemu-devel@nongnu.org, qemu-block@nongnu.org, Anthony Perard , Paul Durrant , Stefano Stabellini , Max Reitz , armbru@redhat.com Am 02.11.2018 um 11:00 hat Tim Smith geschrieben: > A series of performance improvements for disks using the Xen PV ring. > > These have had fairly extensive testing. > > The batching and latency improvements together boost the throughput > of small reads and writes by two to six percent (measured using fio > in the guest) > > Avoiding repeated calls to posix_memalign() reduced the dirty heap > from 25MB to 5MB in the case of a single datapath process while also > improving performance. > > v2 removes some checkpatch complaints and fixes the CCs Completely unrelated, but since you're the first person touching xen_disk in a while, you're my victim: At KVM Forum we discussed sending a patch to deprecate xen_disk because after all those years, it still hasn't been converted to qdev. Markus is currently fixing some other not yet qdevified block device, but after that xen_disk will be the only one left. A while ago, a downstream patch review found out that there are some QMP commands that would immediately crash if a xen_disk device were present because of the lacking qdevification. This is not the code quality standard I envision for QEMU. It's time for non-qdev devices to go. So if you guys are still interested in the device, could someone please finally look into converting it? Kevin