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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A8E36C43217 for ; Thu, 13 Oct 2022 16:01:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229782AbiJMQBY (ORCPT ); Thu, 13 Oct 2022 12:01:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44944 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229790AbiJMQBX (ORCPT ); Thu, 13 Oct 2022 12:01:23 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7441713333B for ; Thu, 13 Oct 2022 09:01:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1665676879; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=8zDpItjAu5ov3bsFW3VuwHkUUIWynjpwr1yozwTgapc=; b=WR9+OsgcaBgrtuRQUbsjQCyDvemj9CboaHmgnwL47PUGTOAwHKt66iLBOdpsW3MFawhELp HUTBW9TaGjCYOCdeNhzb87SHUzXLwz/mF9AQRCx/DW3TTBBaRjrqWcxp/BOV+HXqgDAbY4 idFn7PgHcbfFnJmU6nK08GgAMriW+aI= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-623-d12DpK2UMWyMz9fvft9LNA-1; Thu, 13 Oct 2022 12:01:14 -0400 X-MC-Unique: d12DpK2UMWyMz9fvft9LNA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id BFF16811E7A; Thu, 13 Oct 2022 16:01:13 +0000 (UTC) Received: from localhost (unknown [10.39.194.71]) by smtp.corp.redhat.com (Postfix) with ESMTP id A3D1840398B1; Thu, 13 Oct 2022 16:01:12 +0000 (UTC) Date: Thu, 13 Oct 2022 12:01:10 -0400 From: Stefan Hajnoczi To: Ming Lei Cc: Stefan Hajnoczi , "Richard W.M. Jones" , io-uring@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, Kirill Tkhai , Manuel Bentele , qemu-devel@nongnu.org, Kevin Wolf , Xie Yongji , "Denis V. Lunev" , Stefano Garzarella Subject: Re: ublk-qcow2: ublk-qcow2 is available Message-ID: References: <20221006101400.GC7636@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="Dz5/1ZuMbMXxUtqp" Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org --Dz5/1ZuMbMXxUtqp Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Oct 13, 2022 at 09:50:55AM +0800, Ming Lei wrote: > On Wed, Oct 12, 2022 at 10:15:28AM -0400, Stefan Hajnoczi wrote: > > On Thu, 6 Oct 2022 at 06:14, Richard W.M. Jones wro= te: > > > > > > On Tue, Oct 04, 2022 at 09:53:32AM -0400, Stefan Hajnoczi wrote: > > > > qemu-nbd doesn't use io_uring to handle the backend IO, > > > > > > Would this be fixed by your (not yet upstream) libblkio driver for > > > qemu? > >=20 > > I was wrong, qemu-nbd has syntax to use io_uring: > >=20 > > $ qemu-nbd ... --image-opts driver=3Dfile,filename=3Dtest.img,aio=3Di= o_uring >=20 > Yeah, I saw the option, previously when I tried io_uring via: >=20 > qemu-nbd -c /dev/nbd11 -n --aio=3Dio_uring $my_file >=20 > It complains that 'qemu-nbd: Invalid aio mode 'io_uring'' even though > that 'qemu-nbd --help' does say that io_uring is supported. >=20 > Today just tried it on Fedora 37, looks it starts working with > --aio=3Dio_uring, but the IOPS is basically same with --aio=3Dnative, and > IO trace shows that io_uring is used by qemu-nbd. Okay, similar performance to Linux AIO is expected. That's what we've seen with io_uring in QEMU. QEMU doesn't use io_uring in polling mode, so it's similar to what we get with Linux AIO. Stefan --Dz5/1ZuMbMXxUtqp Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmNINkYACgkQnKSrs4Gr c8ib3Qf/Tgw+o0jMenLQv3Ye1i9s4Mg9WNyB6eTM6ksmacLnBLbt225EDtkqMEqS wRPgsH9kB6d7yKcgAg3HR4/NoZHS+LCkLH4KCw0SyJxzQdecuDazPPQUOMN2U1D3 wBj7ZZDv1In33uW587li1IMtzAajS9BVGwbXSCRK7ZqtaDF0WR85RIDFPbjOMrYK q9fmplUuSVqxYfAQ0deUiO3pM04CoVWdMpdJorpiUDRD6fJdCZBvNNXAxYov8O+8 4Hh7Eyt7MpCwhQUR3cKc/TguVTbbza/uVc8k5o5vBrK0eftv9cT7lUr3+35AnPE4 y+FLbhkaGFOFn4Q0jZDOjcjMRJkdNg== =QYko -----END PGP SIGNATURE----- --Dz5/1ZuMbMXxUtqp--