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=-8.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 B0B1BC34056 for ; Wed, 19 Feb 2020 17:59:44 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 81BE724656 for ; Wed, 19 Feb 2020 17:59:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="FX2cxlfv" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 81BE724656 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 ([::1]:57728 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j4TdP-0007X9-Nt for qemu-devel@archiver.kernel.org; Wed, 19 Feb 2020 12:59:43 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:54099) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j4Tbw-0005Jm-Ed for qemu-devel@nongnu.org; Wed, 19 Feb 2020 12:58:13 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j4Tbu-0000wO-Nx for qemu-devel@nongnu.org; Wed, 19 Feb 2020 12:58:11 -0500 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:37140 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1j4Tbu-0000vN-KI for qemu-devel@nongnu.org; Wed, 19 Feb 2020 12:58:10 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582135089; 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=aoMcZECwJyOP1Gq85SIjQEettvg8amgYeWvqcmYe9nc=; b=FX2cxlfvf5hAfGGDuubDsw3KNktpvpdMxvFpn5ao+DRXI33Lge/R69ggLRqtyA+8TjzKR3 aWm6DUjRsK1U8LcIZFqJtGeBmkrCZLK6I0Y3mUIEN1qOEq69fkaN65L0D73RZr7T7Umpx0 Gw+Cacj6FzTQ+Z2C7tZl7xZtd+cDDzI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-96-CU0ZuIcaNweg1sy6yK-aoQ-1; Wed, 19 Feb 2020 12:58:00 -0500 X-MC-Unique: CU0ZuIcaNweg1sy6yK-aoQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 53F14107ACC5; Wed, 19 Feb 2020 17:57:59 +0000 (UTC) Received: from localhost (unknown [10.36.118.184]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9AF9648; Wed, 19 Feb 2020 17:57:58 +0000 (UTC) Date: Wed, 19 Feb 2020 15:14:16 +0000 From: Stefan Hajnoczi To: Denis Plotnikov Subject: Re: [PATCH v3] virtio: increase virtqueue size for virtio-scsi and virtio-blk Message-ID: <20200219151416.GJ1078625@stefanha-x1.localdomain> References: <20200214074648.958-1-dplotnikov@virtuozzo.com> MIME-Version: 1.0 In-Reply-To: <20200214074648.958-1-dplotnikov@virtuozzo.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="NgG1H2o5aFKkgPy/" Content-Disposition: inline X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.61 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, fam@euphon.net, ehabkost@redhat.com, qemu-block@nongnu.org, mst@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com, pbonzini@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --NgG1H2o5aFKkgPy/ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Feb 14, 2020 at 10:46:48AM +0300, Denis Plotnikov wrote: > The goal is to reduce the amount of requests issued by a guest on > 1M reads/writes. This rises the performance up to 4% on that kind of > disk access pattern. >=20 > The maximum chunk size to be used for the guest disk accessing is > limited with seg_max parameter, which represents the max amount of > pices in the scatter-geather list in one guest disk request. >=20 > Since seg_max is virqueue_size dependent, increasing the virtqueue > size increases seg_max, which, in turn, increases the maximum size > of data to be read/write from a guest disk. >=20 > More details in the original problem statment: > https://lists.gnu.org/archive/html/qemu-devel/2017-12/msg03721.html >=20 > Suggested-by: Denis V. Lunev > Signed-off-by: Denis Plotnikov >=20 > --- >=20 > v3: > * typos fixed >=20 > v2: > * seg_max default value changing removed > --- > hw/block/virtio-blk.c | 2 +- > hw/core/machine.c | 2 ++ > hw/scsi/virtio-scsi.c | 2 +- > 3 files changed, 4 insertions(+), 2 deletions(-) Thanks, applied to my block tree: https://github.com/stefanha/qemu/commits/block Stefan --NgG1H2o5aFKkgPy/ Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAl5NUMgACgkQnKSrs4Gr c8i32Af/b3yKup0k8k+MZPXrxYV8oQkiTpBuHdtOH8wceXUMWvDeXJBGbixtJqr+ H1udQ2JVezNrOR+ZI/R0I8ZxSCfM9Zabqesn0QyYKAsURzajmaemMUdW4AYf8H0u oIpyg7jcLn0yVX7hjEg2vtg+xvgjNofq9SCT+H+8dRkuv7lmxoVl6pq9V710A91k ew063dldBOLcbeVbJpzqRi2kg6WMubZacFYxOHLmNBK+1GS1aNKGBIiZ1KKEqhw4 k6amBFGb+8W6IAMpElmUTqi6wyL6oTcw3hSmHlCLtaVqYzvfQ0WNoxo5PkvEfkhk zRjSvNgQVa3m3DZkMz/tLvaquqoCsA== =QAsH -----END PGP SIGNATURE----- --NgG1H2o5aFKkgPy/--