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=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 155A7C2D0DB for ; Thu, 30 Jan 2020 14:59:43 +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 D30BD2051A for ; Thu, 30 Jan 2020 14:59:42 +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="jS6/DiY1" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D30BD2051A 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]:33878 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ixBIE-0005xM-2q for qemu-devel@archiver.kernel.org; Thu, 30 Jan 2020 09:59:42 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:46381) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ixBHW-0005JF-67 for qemu-devel@nongnu.org; Thu, 30 Jan 2020 09:58:59 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ixBHU-0004Uz-VJ for qemu-devel@nongnu.org; Thu, 30 Jan 2020 09:58:58 -0500 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:29027 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 1ixBHU-0004Ug-R2 for qemu-devel@nongnu.org; Thu, 30 Jan 2020 09:58:56 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580396336; 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=mMrncPKYJjEF+ysiZnqEvv0QLKUhyIsU36C4jrTRlic=; b=jS6/DiY1TfzSsEDYJiMp44pMbJ2exl94WWD9LxVatK16xukgDw5J418CHB7JfVs2kCvR22 LH/blcqdGEmyukyBUKL70p6PDWQw3R2s1CAIkCIdeDgdGr9wLboE0koGGELfqAJwwQgsBu xIiWZfSKs9JC+2xYzuzswvXJt2u3gUk= 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-198-tY8kBWQpPGqejHMtuyRH2Q-1; Thu, 30 Jan 2020 09:58:46 -0500 X-MC-Unique: tY8kBWQpPGqejHMtuyRH2Q-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A439CDB60; Thu, 30 Jan 2020 14:58:44 +0000 (UTC) Received: from localhost (unknown [10.36.118.87]) by smtp.corp.redhat.com (Postfix) with ESMTP id BB81C100194E; Thu, 30 Jan 2020 14:58:41 +0000 (UTC) Date: Thu, 30 Jan 2020 14:58:40 +0000 From: Stefan Hajnoczi To: Denis Plotnikov Subject: Re: [PATCH v1 2/4] virtio: increase virtuqueue size for virtio-scsi and virtio-blk Message-ID: <20200130145840.GH180311@stefanha-x1.localdomain> References: <20200129140702.5411-1-dplotnikov@virtuozzo.com> <20200129140702.5411-3-dplotnikov@virtuozzo.com> MIME-Version: 1.0 In-Reply-To: <20200129140702.5411-3-dplotnikov@virtuozzo.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="MGu/vTNewDGZ7tmp" 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: fam@euphon.net, kwolf@redhat.com, vsementsov@virtuozzo.com, ehabkost@redhat.com, qemu-block@nongnu.org, mst@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com, pbonzini@redhat.com, den@virtuozzo.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --MGu/vTNewDGZ7tmp Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Jan 29, 2020 at 05:07:00PM +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 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 > --- > hw/core/machine.c | 3 +++ > include/hw/virtio/virtio.h | 2 +- > 2 files changed, 4 insertions(+), 1 deletion(-) >=20 > diff --git a/hw/core/machine.c b/hw/core/machine.c > index 3e288bfceb..8bc401d8b7 100644 > --- a/hw/core/machine.c > +++ b/hw/core/machine.c > @@ -28,6 +28,9 @@ > #include "hw/mem/nvdimm.h" > =20 > GlobalProperty hw_compat_4_2[] =3D { > + { "virtio-blk-device", "queue-size", "128"}, > + { "virtio-scsi-device", "virtqueue_size", "128"}, > + { "vhost-blk-device", "virtqueue_size", "128"}, vhost-blk-device?! Who has this? It's not in qemu.git so please omit this line. ;-) On the other hand, do you want to do this for the vhost-user-blk, vhost-user-scsi, and vhost-scsi devices that exist in qemu.git? Those devices would benefit from better performance too. --MGu/vTNewDGZ7tmp Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAl4y7yAACgkQnKSrs4Gr c8j3yQf/fLGA6WL61DUwvEFDPvkiK2PNNcRnC5FvlEoenP8Dk8Q8Ol3aeQLlpJ4C 14jyZU10YvWn6WeMtPYTyC3wbv++w7J9irpJsimJHPfcl7zOqxSV4D6lvN1l0gAu SiS0YotiJwrN5aUNWJsXfJcmUtZKD/LgmLcK2SqD5mi5Q1mHgeUT5vxVCKXxizIH BvNd1bdTpOhQNF5Y1nw3MhQJNdFJAnVOhQxghHZrGcKARSFX6QtHqNjcVhZQklF4 sBAd3sVSZoYJZjs8letLPVUG4ftR8h4EbCMoHcSIgf4TZBXolZ7yA/ktCfZlO/1E DOPAveWr/Ji58v2bG2xyA2LaOSMEhQ== =9G86 -----END PGP SIGNATURE----- --MGu/vTNewDGZ7tmp--