From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5ADB6C0044C for ; Mon, 5 Nov 2018 11:55:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 15A4E20825 for ; Mon, 5 Nov 2018 11:55:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 15A4E20825 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728827AbeKEVOw (ORCPT ); Mon, 5 Nov 2018 16:14:52 -0500 Received: from mx1.redhat.com ([209.132.183.28]:59584 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726358AbeKEVOw (ORCPT ); Mon, 5 Nov 2018 16:14:52 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 3A9A7308212A; Mon, 5 Nov 2018 11:55:30 +0000 (UTC) Received: from dhcp-4-67.tlv.redhat.com (dhcp-4-67.tlv.redhat.com [10.35.4.67]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4BAF8672C2; Mon, 5 Nov 2018 11:55:26 +0000 (UTC) Message-ID: <71ed924dfecf358f6e13a0d1897f94e148058b4a.camel@redhat.com> Subject: Re: [PATCH 0/1] vhost: add vhost_blk driver From: Maxim Levitsky To: Vitaly Mayatskih Cc: "Michael S . Tsirkin" , Jason Wang , Paolo Bonzini , kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Date: Mon, 05 Nov 2018 13:55:24 +0200 In-Reply-To: References: <20181102182123.29420-1-v.mayatskih@gmail.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Mon, 05 Nov 2018 11:55:30 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 2018-11-04 at 11:40 -0500, Vitaly Mayatskih wrote: > On Sun, Nov 4, 2018 at 6:57 AM Maxim Levitsky wrote: > > > Hi! > > I am also working in this area, and so I am very intersted in this driver. > > > > > 1 171k 151k 148k 151k 195k 187k 175k > > > > If I understand correctly this is fio --numjobs=1? > > It looks like you are getting better that native performance over bare metal > > in > > E,F,G (vhost-blk cases in fact). Is this correct? > > Yes. At such speeds it is a matter of how the workers are scheduled, > i.e. how good is batching. There are other factors why vhost-blk is on > par or slightly higher than fio running in userspace on bare metal, > but from my observation the right batching all through the stack is > more important. I completely agree with you on that. I currently learning profiling/tracing to understand the batching (or lack of) in the tests I run My focus currently is mostly on spdk + native nvme While for multiple threads, the performance is very close to bare metal, on single thread I see significant overhead which probably relate to batching as well. > > > Could you share the full fio command line you have used? > > sysctl -w vm.nr_hugepages=8300; numactl -p 1 -N 1 ./qemu-system-x86_64 > -enable-kvm -cpu host -smp 16 -mem-prealloc -mem-path > /dev/hugepages/foo -m 8G -nographic -drive > if=none,id=drive0,format=raw,file=/dev/mapper/mirror-hello,cache=none > -device virtio-blk-pci,id=blk0,drive=drive0,num-queues=16 -drive > if=none,id=drive1,format=raw,file=/dev/mapper/mirror-volume,cache=none > -device vhost-blk-pci,id=blk1,drive=drive1,num-queues=16 Thanks! > > for i in `seq 1 16`; do echo -n "$i "; ./fio --direct=1 --rw=randread > --ioengine=libaio --bs=4k --iodepth=128 --numjobs=$i --name=foo > --time_based --runtime=15 --group_reporting --filename=/dev/vda > --size=10g | grep -Po 'IOPS=[0-9\.]*k'; done > > > Which IO device did you use for the test? NVME? > > That was LVM mirror over 2 network disks. On the target side it was > LVM stripe over few NVMe's. Have you tried to test this over directly connected NVME device to? The networking might naturally improve batching I think. > > > Which system (cpu model/number of cores/etc) did you test on? > > Dual socket: "model name : Intel(R) Xeon(R) Gold 6142 CPU @ > 2.60GHz" with HT enabled, so 64 logical cores in total. The network > was something from Intel with 53 Gbps PHY and served by fm10k driver. All right, thanks! I'll test your driver on my system where I tested most of the current solutions. Best regards, Maxim Levitsky