From: Joanna Rutkowska <joanna@invisiblethingslab.com>
To: Jan Beulich <JBeulich@suse.com>
Cc: Marek Marczykowski <marmarek@invisiblethingslab.com>,
xen-devel <xen-devel@lists.xen.org>
Subject: Re: Noticeably poor Intel GPU performance on 3.3 and 3.4 dom0 kernels
Date: Thu, 31 May 2012 11:15:03 +0200 [thread overview]
Message-ID: <4FC73697.20509@invisiblethingslab.com> (raw)
In-Reply-To: <4FC614770200007800086D0C@nat28.tlf.novell.com>
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On 05/30/12 12:37, Jan Beulich wrote:
>>>> On 30.05.12 at 12:14, Joanna Rutkowska <joanna@invisiblethingslab.com> wrote:
>> > I've recently been some newer Dom0 kernels (3.3.5, 3.4) under Xen 4.1.2,
>> > and have noticed that those kernel noticeably downgrade performance of
>> > (at least) Intel GPUs. This is easily noticeable even on such trivial
>> > tasks as scrolling a webpage in Firefox or Chrome. This slow GPU
>> > performance on 3.3 and 3.4 kernels is in stark contrast with what I see
>> > on 3.2.7 Dom0 kernel, where graphics works just great...
>> >
>> > In order to make sure that this is not caused by power management set
>> > too strictly, I played with xenpm and made sure to set the following:
>> > 1) xenpm set-scaling-governor performance
>> > 2) xenpm set-max-cstate 0
>> >
>> > I have verified then that my processor: 1) keeps staying in P0 state
>> > (so, max frequency), and 2) keeps staying in C0 state.
>> >
>> > Those setting didn't change anything regarding the poor graphics
>> > performance, though.
>> >
>> > Any ideas what else I could test to find out the cause of this?
> To check whether the DRM drivers' supposedly more extensive
> use of the DMA API is the reason, could you check whether the
> performance is as bad with "mem=4G" on the Xen command line?
With mem=4G xen option, the graphics performance is just as poor as without.
joanna.
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next prev parent reply other threads:[~2012-05-31 9:15 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-30 10:14 Noticeably poor Intel GPU performance on 3.3 and 3.4 dom0 kernels Joanna Rutkowska
2012-05-30 10:37 ` Jan Beulich
2012-05-31 9:15 ` Joanna Rutkowska [this message]
2012-05-30 14:28 ` Konrad Rzeszutek Wilk
2012-05-30 14:57 ` Marek Marczykowski
2012-05-30 21:21 ` Konrad Rzeszutek Wilk
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