From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44322) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cUcE6-0008Bi-1W for qemu-devel@nongnu.org; Fri, 20 Jan 2017 11:39:47 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cUcE2-00017o-OX for qemu-devel@nongnu.org; Fri, 20 Jan 2017 11:39:46 -0500 Received: from mail-wm0-x242.google.com ([2a00:1450:400c:c09::242]:35231) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cUcE2-000170-IO for qemu-devel@nongnu.org; Fri, 20 Jan 2017 11:39:42 -0500 Received: by mail-wm0-x242.google.com with SMTP id d140so7970925wmd.2 for ; Fri, 20 Jan 2017 08:39:42 -0800 (PST) Sender: Paolo Bonzini References: <20170113131731.1246-1-pbonzini@redhat.com> <20170118160315.GS30347@stefanha-x1.localdomain> <08705645-17e8-1ffa-4199-c962f7198ab3@redhat.com> <20170119170128.GD27032@stefanha-x1.localdomain> From: Paolo Bonzini Message-ID: <0969c169-772e-d213-675a-30aee616f8a8@redhat.com> Date: Fri, 20 Jan 2017 17:39:40 +0100 MIME-Version: 1.0 In-Reply-To: <20170119170128.GD27032@stefanha-x1.localdomain> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [PATCH 00/16] aio_context_acquire/release pushdown, part 2 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi Cc: famz@redhat.com, qemu-devel@nongnu.org On 19/01/2017 18:01, Stefan Hajnoczi wrote: >>> This is a big and somewhat risky change. Have you run any performance >>> benchmarks? >> >> Not recently; I ran them a year ago and there was no measurable difference. > > Good, please re-run for the final version. Done, went better than expected. :) base 4k-1 null READ: io=6646.8MB, aggrb=226852KB/s, minb=226852KB/s, maxb=226852KB/s, mint=30000msec, maxt=30000msec 4k-1 nvme READ: io=3086.4MB, aggrb=105342KB/s, minb=105342KB/s, maxb=105342KB/s, mint=30001msec, maxt=30001msec 4k-32 nvme READ: io=14246MB, aggrb=486241KB/s, minb=486241KB/s, maxb=486241KB/s, mint=30001msec, maxt=30001msec patched: 4k-1 null READ: io=7044.5MB, aggrb=240436KB/s, minb=240436KB/s, maxb=240436KB/s, mint=30000msec, maxt=30000msec 4k-1 nvme READ: io=3463.3MB, aggrb=118208KB/s, minb=118208KB/s, maxb=118208KB/s, mint=30001msec, maxt=30001msec 4k-32 nvme READ: io=15217MB, aggrb=519378KB/s, minb=519378KB/s, maxb=519378KB/s, mint=30001msec, maxt=30001msec null is null-co://, nvme is a fast (180kIOPS on bare-metal) NVMe SSD. So it seems to be some 5-10% faster. No idea why so I would not give too much importance on the numbers, but at least it's not worse. Paolo