From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:40052) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hKEtM-0004qY-N8 for qemu-devel@nongnu.org; Sat, 27 Apr 2019 00:24:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hKEtL-0005wM-Na for qemu-devel@nongnu.org; Sat, 27 Apr 2019 00:24:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43704) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hKEtL-0005uz-Hc for qemu-devel@nongnu.org; Sat, 27 Apr 2019 00:24:47 -0400 Date: Sat, 27 Apr 2019 00:24:45 -0400 (EDT) From: Paolo Bonzini Message-ID: <825292440.15675844.1556339085478.JavaMail.zimbra@redhat.com> In-Reply-To: <7044D39A-8D7B-41F7-B8C3-DC2214E6826A@oracle.com> References: <5FF901C1-0AA5-4308-A65C-C448D0A2BA63@oracle.com> <898ef1d4-bfa2-9952-8ceb-f1282b85e29c@oracle.com> <20190416092042.GB32709@stefanha-x1.localdomain> <8E5AF770-69ED-4D44-8A25-B51344996D9E@oracle.com> <3F7E854A-3C1D-4204-8C35-893FC0614796@oracle.com> <20190423120453.GF32465@stefanha-x1.localdomain> <44520476-d6a8-2e3f-1602-388e2e1e874e@redhat.com> <7044D39A-8D7B-41F7-B8C3-DC2214E6826A@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] Following up questions related to QEMU and I/O Thread List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Wei Li Cc: Stefan Hajnoczi , Stefan Hajnoczi , Dongli Zhang , qemu-devel@nongnu.org > Thanks Stefan and Paolo for your response and advice! > > Hi Paolo, > > As to the virtio-scsi batch I/O submission feature in QEMU which you > mentioned, is this feature turned on by default in QEMU 2.9 or there is a > tunable parameters to turn on/off the feature? Yes, it is available by default since 2.2.0. It cannot be turned off, however it is only possible to batch I/O with aio=native (and, since 2.12.0, with the NVMe backend). Paolo 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=-0.9 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 83DBCC43219 for ; Sat, 27 Apr 2019 04:25:41 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 49F88206BF for ; Sat, 27 Apr 2019 04:25:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 49F88206BF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([127.0.0.1]:55433 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hKEuC-0005Yo-6x for qemu-devel@archiver.kernel.org; Sat, 27 Apr 2019 00:25:40 -0400 Received: from eggs.gnu.org ([209.51.188.92]:40052) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hKEtM-0004qY-N8 for qemu-devel@nongnu.org; Sat, 27 Apr 2019 00:24:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hKEtL-0005wM-Na for qemu-devel@nongnu.org; Sat, 27 Apr 2019 00:24:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43704) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hKEtL-0005uz-Hc for qemu-devel@nongnu.org; Sat, 27 Apr 2019 00:24:47 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id EB00530B27BE; Sat, 27 Apr 2019 04:24:45 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id DCBE427BA2; Sat, 27 Apr 2019 04:24:45 +0000 (UTC) Received: from zmail18.collab.prod.int.phx2.redhat.com (zmail18.collab.prod.int.phx2.redhat.com [10.5.83.21]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id B04843FB10; Sat, 27 Apr 2019 04:24:45 +0000 (UTC) Date: Sat, 27 Apr 2019 00:24:45 -0400 (EDT) From: Paolo Bonzini To: Wei Li Message-ID: <825292440.15675844.1556339085478.JavaMail.zimbra@redhat.com> In-Reply-To: <7044D39A-8D7B-41F7-B8C3-DC2214E6826A@oracle.com> References: <5FF901C1-0AA5-4308-A65C-C448D0A2BA63@oracle.com> <898ef1d4-bfa2-9952-8ceb-f1282b85e29c@oracle.com> <20190416092042.GB32709@stefanha-x1.localdomain> <8E5AF770-69ED-4D44-8A25-B51344996D9E@oracle.com> <3F7E854A-3C1D-4204-8C35-893FC0614796@oracle.com> <20190423120453.GF32465@stefanha-x1.localdomain> <44520476-d6a8-2e3f-1602-388e2e1e874e@redhat.com> <7044D39A-8D7B-41F7-B8C3-DC2214E6826A@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [93.56.166.5, 10.4.196.15, 10.5.101.130, 10.4.195.24] Thread-Topic: [Qemu-devel] Following up questions related to QEMU and I/O Thread Thread-Index: nrya/PIFCrUmu8omI+ihQgdYpvhqFg== X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Sat, 27 Apr 2019 04:24:46 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] Following up questions related to QEMU and I/O Thread X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Stefan Hajnoczi , qemu-devel@nongnu.org, Stefan Hajnoczi , Dongli Zhang Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Message-ID: <20190427042445.yrGk3SnaRcx5w1GPDAjiiPiA95STQMTfun6z4jwLOrs@z> > Thanks Stefan and Paolo for your response and advice! > > Hi Paolo, > > As to the virtio-scsi batch I/O submission feature in QEMU which you > mentioned, is this feature turned on by default in QEMU 2.9 or there is a > tunable parameters to turn on/off the feature? Yes, it is available by default since 2.2.0. It cannot be turned off, however it is only possible to batch I/O with aio=native (and, since 2.12.0, with the NVMe backend). Paolo