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From: Rusty Russell <rusty@rustcorp.com.au>
To: Dongsu Park <dongsu.park@profitbricks.com>, qemu-devel@nongnu.org
Cc: kvm@vger.kernel.org
Subject: Re: virtio-blk performance regression and qemu-kvm
Date: Mon, 13 Feb 2012 10:25:59 +1030	[thread overview]
Message-ID: <87sjifd2sw.fsf@rustcorp.com.au> (raw)
In-Reply-To: <20120210143639.GA17883@gmail.com>

On Fri, 10 Feb 2012 15:36:39 +0100, Dongsu Park <dongsu.park@profitbricks.com> wrote:
> Hi,
> 
> Recently I observed performance regression regarding virtio-blk,
> especially different IO bandwidths between qemu-kvm 0.14.1 and 1.0.
> So I want to share the benchmark results, and ask you what the reason
> would be.

Interesting.  There are two obvious possibilities here.  One is that
qemu has regressed, the other is that virtio_blk has regressed; the new
qemu may negotiate new features.  Please do the following in the guest
with old and new qemus:

cat /sys/class/block/vdb/device/features

(eg, here that gives: 0010101101100000000000000000100e0).

Thanks,
Rusty.

WARNING: multiple messages have this Message-ID (diff)
From: Rusty Russell <rusty@rustcorp.com.au>
To: Dongsu Park <dongsu.park@profitbricks.com>, qemu-devel@nongnu.org
Cc: kvm@vger.kernel.org
Subject: Re: [Qemu-devel] virtio-blk performance regression and qemu-kvm
Date: Mon, 13 Feb 2012 10:25:59 +1030	[thread overview]
Message-ID: <87sjifd2sw.fsf@rustcorp.com.au> (raw)
In-Reply-To: <20120210143639.GA17883@gmail.com>

On Fri, 10 Feb 2012 15:36:39 +0100, Dongsu Park <dongsu.park@profitbricks.com> wrote:
> Hi,
> 
> Recently I observed performance regression regarding virtio-blk,
> especially different IO bandwidths between qemu-kvm 0.14.1 and 1.0.
> So I want to share the benchmark results, and ask you what the reason
> would be.

Interesting.  There are two obvious possibilities here.  One is that
qemu has regressed, the other is that virtio_blk has regressed; the new
qemu may negotiate new features.  Please do the following in the guest
with old and new qemus:

cat /sys/class/block/vdb/device/features

(eg, here that gives: 0010101101100000000000000000100e0).

Thanks,
Rusty.

  reply	other threads:[~2012-02-12 23:59 UTC|newest]

Thread overview: 52+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-02-10 14:36 virtio-blk performance regression and qemu-kvm Dongsu Park
2012-02-10 14:36 ` [Qemu-devel] " Dongsu Park
2012-02-12 23:55 ` Rusty Russell [this message]
2012-02-12 23:55   ` Rusty Russell
2012-02-21 16:45   ` Dongsu Park
2012-02-21 16:45     ` [Qemu-devel] " Dongsu Park
2012-02-21 22:16     ` Rusty Russell
2012-02-21 22:16       ` [Qemu-devel] " Rusty Russell
2012-02-13 11:57 ` Stefan Hajnoczi
2012-02-13 11:57   ` [Qemu-devel] " Stefan Hajnoczi
2012-02-21 15:57   ` Dongsu Park
2012-02-21 15:57     ` [Qemu-devel] " Dongsu Park
2012-02-21 17:27     ` Stefan Hajnoczi
2012-02-21 17:27       ` [Qemu-devel] " Stefan Hajnoczi
2012-02-22 16:48       ` Dongsu Park
2012-02-22 16:48         ` [Qemu-devel] " Dongsu Park
2012-02-22 19:53         ` Stefan Hajnoczi
2012-02-22 19:53           ` [Qemu-devel] " Stefan Hajnoczi
2012-02-28 16:39           ` Martin Mailand
2012-02-28 16:39             ` [Qemu-devel] " Martin Mailand
2012-02-28 17:05             ` Stefan Hajnoczi
2012-02-28 17:05               ` [Qemu-devel] " Stefan Hajnoczi
2012-02-28 17:15               ` Martin Mailand
2012-02-28 17:15                 ` [Qemu-devel] " Martin Mailand
2012-02-29  8:38                 ` Stefan Hajnoczi
2012-02-29  8:38                   ` [Qemu-devel] " Stefan Hajnoczi
2012-02-29 13:12                   ` Martin Mailand
2012-02-29 13:12                     ` [Qemu-devel] " Martin Mailand
2012-02-29 13:44                     ` Stefan Hajnoczi
2012-02-29 13:44                       ` [Qemu-devel] " Stefan Hajnoczi
2012-02-29 13:52                       ` Stefan Hajnoczi
2012-02-29 13:52                         ` [Qemu-devel] " Stefan Hajnoczi
2012-03-05 16:13 ` Martin Mailand
2012-03-05 16:13   ` [Qemu-devel] " Martin Mailand
2012-03-05 16:35   ` Stefan Hajnoczi
2012-03-05 16:35     ` [Qemu-devel] " Stefan Hajnoczi
2012-03-05 16:44     ` Martin Mailand
2012-03-05 16:44       ` [Qemu-devel] " Martin Mailand
2012-03-06 12:59       ` Stefan Hajnoczi
2012-03-06 12:59         ` [Qemu-devel] " Stefan Hajnoczi
2012-03-06 22:07         ` Reeted
2012-03-06 22:07           ` Reeted
2012-03-07  8:04           ` Stefan Hajnoczi
2012-03-07 14:21             ` Reeted
2012-03-07 14:33               ` Stefan Hajnoczi
2012-03-07 14:33                 ` Stefan Hajnoczi
2012-03-07 10:39         ` Martin Mailand
2012-03-07 10:39           ` [Qemu-devel] " Martin Mailand
2012-03-07 11:21           ` Paolo Bonzini
2012-03-07 11:21             ` [Qemu-devel] " Paolo Bonzini
2012-03-06 14:32   ` Dongsu Park
2012-03-06 14:32     ` [Qemu-devel] " Dongsu Park

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