From: Stefan Hajnoczi <stefanha@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: "Kevin Wolf" <kwolf@redhat.com>, "Fam Zheng" <fam@euphon.net>,
"Daniel P. Berrangé" <berrange@redhat.com>,
"Eduardo Habkost" <ehabkost@redhat.com>,
qemu-block@nongnu.org, "Sergio Lopez" <slp@redhat.com>,
"Cornelia Huck" <cohuck@redhat.com>,
qemu-devel@nongnu.org, "Max Reitz" <mreitz@redhat.com>,
"Paolo Bonzini" <pbonzini@redhat.com>
Subject: Re: [PATCH v2 2/4] virtio-scsi: default num_queues to -smp N
Date: Wed, 12 Feb 2020 11:18:32 +0000 [thread overview]
Message-ID: <20200212111832.GD464050@stefanha-x1.localdomain> (raw)
In-Reply-To: <20200211113108-mutt-send-email-mst@kernel.org>
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On Tue, Feb 11, 2020 at 11:31:17AM -0500, Michael S. Tsirkin wrote:
> On Tue, Feb 11, 2020 at 04:20:41PM +0000, Stefan Hajnoczi wrote:
> > On Mon, Feb 03, 2020 at 12:39:49PM +0100, Sergio Lopez wrote:
> > > On Mon, Feb 03, 2020 at 10:57:44AM +0000, Daniel P. Berrangé wrote:
> > > > On Mon, Feb 03, 2020 at 11:25:29AM +0100, Sergio Lopez wrote:
> > > > > On Thu, Jan 30, 2020 at 10:52:35AM +0000, Stefan Hajnoczi wrote:
> > > > > > On Thu, Jan 30, 2020 at 01:29:16AM +0100, Paolo Bonzini wrote:
> > > > > > > On 29/01/20 16:44, Stefan Hajnoczi wrote:
> > > > > > > > On Mon, Jan 27, 2020 at 02:10:31PM +0100, Cornelia Huck wrote:
> > > > > > > >> On Fri, 24 Jan 2020 10:01:57 +0000
> > > > > > > >> Stefan Hajnoczi <stefanha@redhat.com> wrote:
> > I will create a 32 vCPU guest with 100 virtio-blk devices and verify
> > that enabling multi-queue is successful.
>
> and that it's helpful for performance?
I may be a little while before the next revision of this patch series.
Testing reveals scalability problems when creating so many virtqueues
:).
I've measured boot time, memory consumption, and random read IOPS. They
are all significantly worse (32 vCPUs, 24 GB RAM, 101 virtio-blk
devices, 32 queues/device).
Time to see what's going on and whether some general scalability
improvements are possible here before we enable multi-queue by default.
Stefan
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next prev parent reply other threads:[~2020-02-12 11:19 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-24 10:01 [PATCH v2 0/4] virtio-pci: enable blk and scsi multi-queue by default Stefan Hajnoczi
2020-01-24 10:01 ` [PATCH v2 1/4] virtio-scsi: introduce a constant for fixed virtqueues Stefan Hajnoczi
2020-01-27 12:59 ` Cornelia Huck
2020-01-24 10:01 ` [PATCH v2 2/4] virtio-scsi: default num_queues to -smp N Stefan Hajnoczi
2020-01-27 13:10 ` Cornelia Huck
2020-01-29 15:44 ` Stefan Hajnoczi
2020-01-30 0:29 ` Paolo Bonzini
2020-01-30 10:52 ` Stefan Hajnoczi
2020-01-30 11:03 ` Cornelia Huck
2020-02-03 10:25 ` Sergio Lopez
2020-02-03 10:35 ` Michael S. Tsirkin
2020-02-03 10:51 ` Cornelia Huck
2020-02-03 10:57 ` Daniel P. Berrangé
2020-02-03 11:39 ` Sergio Lopez
2020-02-03 12:53 ` Michael S. Tsirkin
2020-02-11 16:20 ` Stefan Hajnoczi
2020-02-11 16:31 ` Michael S. Tsirkin
2020-02-12 11:18 ` Stefan Hajnoczi [this message]
2020-02-21 10:55 ` Stefan Hajnoczi
2020-01-24 10:01 ` [PATCH v2 3/4] virtio-blk: " Stefan Hajnoczi
2020-01-27 13:14 ` Cornelia Huck
2020-01-24 10:01 ` [PATCH v2 4/4] vhost-user-blk: " Stefan Hajnoczi
2020-01-27 13:17 ` Cornelia Huck
2020-01-27 9:59 ` [PATCH v2 0/4] virtio-pci: enable blk and scsi multi-queue by default Stefano Garzarella
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