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From: Anthony Liguori <anthony@codemonkey.ws>
To: dlaor@redhat.com
Cc: Paolo Bonzini <pbonzini@redhat.com>, Avi Kivity <avi@redhat.com>,
	Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>,
	kvm-devel <kvm@vger.kernel.org>,
	qemu-devel <qemu-devel@nongnu.org>
Subject: Re: Better qemu/kvm defaults (was Re: [RFC PATCH 0/4] Gang scheduling in CFS)
Date: Tue, 03 Jan 2012 16:45:19 -0600	[thread overview]
Message-ID: <4F0384FF.8070207@codemonkey.ws> (raw)
In-Reply-To: <4F0381CF.30204@redhat.com>

On 01/03/2012 04:31 PM, Dor Laor wrote:
>> We can just set this for pc-1.1. I don't see any real harm in doing that.
>
> Great, it 'only' took about 3 years from the time it got developed originally by
> Uri...

Someone just needs to send a patch.

>> When using 'guests-pick', we initially present the most compatible
>> network model (rtl8139, for instance). We would provide a paravirtual
>> channel (guest-agent?) that could be used to enumerate which models were
>> available and let guest decide which model to use for the next reboot.
>> You could also enable immediate switch over using hot plug.
>
> If guest uses an agent, it probably has virtio-serial driver and it indicates it
> has other virtio ones, otherwise, the agent won't fly

Right, but I still you want the ability for the guest to indicate that it would 
like to use virtio drivers or not.

If you think about it, it makes no sense to choose which type of device gets 
used in the hypervisor.  In an ideal world, the guest would just figure out what 
it wants to see and get that.

The same is probably true about most device model properties.  rtc clock slew 
policy is another good example.  Instead of trying to figure out what the guest 
type is, we should just let the guest request device model settings like that.

>>> We need to keep on recommending the best profile for virtualization,
>>> for Fedora
>>> I think it either enterprise-storage and maybe throughput-performance.
>>
>> I think that's more of a distro. It might be worth referring to in our
>> documentation but I'm not sure it's something we can do much about.
>
> Someone said on the kvm community call today: "no one reads documentation", so
> it better be a script. As noted about we do have it in my favorite distribution,
> I hoped all distributions gets it.

Indeed, "referring to it in our documentation" was a polite way of saying, it's 
a distro problem :-)

The distro should let you choose a profile during installation or something like 
that.

Regards,

Anthony Liguori

>
>
>> Regards,
>>
>> Anthony Liguori
>>
>>>
>>> If we have a such a script, it can call the matching tuned profile
>>> instead of
>>> tweaking every /sys option.
>>>
>>>>
>>>> Regards,
>>>>
>>>> Anthony Liguori
>>>>
>>>>> HTH,
>>>>> Dor
>>>>>
>>>>
>>>>
>>>
>>>
>>
>
>

WARNING: multiple messages have this Message-ID (diff)
From: Anthony Liguori <anthony@codemonkey.ws>
To: dlaor@redhat.com
Cc: Paolo Bonzini <pbonzini@redhat.com>, Avi Kivity <avi@redhat.com>,
	Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>,
	kvm-devel <kvm@vger.kernel.org>,
	qemu-devel <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] Better qemu/kvm defaults (was Re: [RFC PATCH 0/4] Gang scheduling in CFS)
Date: Tue, 03 Jan 2012 16:45:19 -0600	[thread overview]
Message-ID: <4F0384FF.8070207@codemonkey.ws> (raw)
In-Reply-To: <4F0381CF.30204@redhat.com>

On 01/03/2012 04:31 PM, Dor Laor wrote:
>> We can just set this for pc-1.1. I don't see any real harm in doing that.
>
> Great, it 'only' took about 3 years from the time it got developed originally by
> Uri...

Someone just needs to send a patch.

>> When using 'guests-pick', we initially present the most compatible
>> network model (rtl8139, for instance). We would provide a paravirtual
>> channel (guest-agent?) that could be used to enumerate which models were
>> available and let guest decide which model to use for the next reboot.
>> You could also enable immediate switch over using hot plug.
>
> If guest uses an agent, it probably has virtio-serial driver and it indicates it
> has other virtio ones, otherwise, the agent won't fly

Right, but I still you want the ability for the guest to indicate that it would 
like to use virtio drivers or not.

If you think about it, it makes no sense to choose which type of device gets 
used in the hypervisor.  In an ideal world, the guest would just figure out what 
it wants to see and get that.

The same is probably true about most device model properties.  rtc clock slew 
policy is another good example.  Instead of trying to figure out what the guest 
type is, we should just let the guest request device model settings like that.

>>> We need to keep on recommending the best profile for virtualization,
>>> for Fedora
>>> I think it either enterprise-storage and maybe throughput-performance.
>>
>> I think that's more of a distro. It might be worth referring to in our
>> documentation but I'm not sure it's something we can do much about.
>
> Someone said on the kvm community call today: "no one reads documentation", so
> it better be a script. As noted about we do have it in my favorite distribution,
> I hoped all distributions gets it.

Indeed, "referring to it in our documentation" was a polite way of saying, it's 
a distro problem :-)

The distro should let you choose a profile during installation or something like 
that.

Regards,

Anthony Liguori

>
>
>> Regards,
>>
>> Anthony Liguori
>>
>>>
>>> If we have a such a script, it can call the matching tuned profile
>>> instead of
>>> tweaking every /sys option.
>>>
>>>>
>>>> Regards,
>>>>
>>>> Anthony Liguori
>>>>
>>>>> HTH,
>>>>> Dor
>>>>>
>>>>
>>>>
>>>
>>>
>>
>
>

  reply	other threads:[~2012-01-03 22:45 UTC|newest]

Thread overview: 95+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-12-19  8:33 [RFC PATCH 0/4] Gang scheduling in CFS Nikunj A. Dadhania
2011-12-19  8:34 ` [RFC PATCH 1/4] sched: Adding cpu.gang file to cpu cgroup Nikunj A. Dadhania
2011-12-19  8:34 ` [RFC PATCH 2/4] sched: Adding gang scheduling infrastrucure Nikunj A. Dadhania
2011-12-19 15:51   ` Peter Zijlstra
2011-12-19 16:51     ` Peter Zijlstra
2011-12-20  1:43       ` Nikunj A Dadhania
2011-12-20  1:39     ` Nikunj A Dadhania
2011-12-19  8:34 ` [RFC PATCH 3/4] sched: Gang using set_next_buddy Nikunj A. Dadhania
2011-12-19  8:35 ` [RFC PATCH 4/4] sched:Implement set_gang_buddy Nikunj A. Dadhania
2011-12-19 15:51   ` Peter Zijlstra
2011-12-20  1:43     ` Nikunj A Dadhania
2011-12-26  2:30     ` Nikunj A Dadhania
2011-12-19 11:23 ` [RFC PATCH 0/4] Gang scheduling in CFS Ingo Molnar
2011-12-19 11:44   ` Avi Kivity
2011-12-19 11:50     ` Nikunj A Dadhania
2011-12-19 11:59       ` Avi Kivity
2011-12-19 12:06         ` Nikunj A Dadhania
2011-12-19 12:50           ` Avi Kivity
2011-12-19 13:09             ` Nikunj A Dadhania
2011-12-19 11:45   ` Nikunj A Dadhania
2011-12-19 13:22     ` Nikunj A Dadhania
2011-12-19 16:28       ` Ingo Molnar
2011-12-21 10:39   ` Nikunj A Dadhania
2011-12-21 10:43     ` Avi Kivity
2011-12-23  3:20       ` Nikunj A Dadhania
2011-12-23 10:36         ` Ingo Molnar
2011-12-25 10:58           ` Avi Kivity
2011-12-25 15:45             ` Avi Kivity
2011-12-26  3:14             ` Nikunj A Dadhania
2011-12-26  9:05               ` Avi Kivity
2011-12-26 11:33                 ` Nikunj A Dadhania
2011-12-26 11:41                   ` Avi Kivity
2011-12-27  1:47                     ` Nikunj A Dadhania
2011-12-27  9:15                       ` Avi Kivity
2011-12-27 10:24                         ` Nikunj A Dadhania
2011-12-29 16:07                 ` Better qemu/kvm defaults (was Re: [RFC PATCH 0/4] Gang scheduling in CFS) Dor Laor
2011-12-29 16:07                   ` [Qemu-devel] " Dor Laor
2011-12-29 16:13                   ` Avi Kivity
2011-12-29 16:13                     ` [Qemu-devel] " Avi Kivity
2011-12-29 16:16                   ` Anthony Liguori
2011-12-29 16:16                     ` Anthony Liguori
2012-01-01 10:16                     ` Dor Laor
2012-01-01 10:16                       ` [Qemu-devel] " Dor Laor
2012-01-01 14:01                       ` Ronen Hod
2012-01-01 14:01                         ` Ronen Hod
2012-01-02  9:37                         ` Dor Laor
2012-01-02  9:37                           ` [Qemu-devel] " Dor Laor
2012-01-03 15:48                       ` Anthony Liguori
2012-01-03 15:48                         ` Anthony Liguori
2012-01-03 22:31                         ` Dor Laor
2012-01-03 22:31                           ` Dor Laor
2012-01-03 22:45                           ` Anthony Liguori [this message]
2012-01-03 22:45                             ` Anthony Liguori
2012-01-03 22:59                             ` Dor Laor
2012-01-03 22:59                               ` Dor Laor
2011-12-27  3:15               ` [RFC PATCH 0/4] Gang scheduling in CFS Nikunj A Dadhania
2011-12-27  9:17                 ` Avi Kivity
2011-12-27  9:44                   ` Nikunj A Dadhania
2011-12-27  9:51                     ` Avi Kivity
2011-12-27 10:10                       ` Nikunj A Dadhania
2011-12-27 10:34                         ` Avi Kivity
2011-12-27 10:43                           ` Nikunj A Dadhania
2011-12-27 10:53                             ` Avi Kivity
2011-12-30  9:51             ` Ingo Molnar
2011-12-30 10:10               ` Nikunj A Dadhania
2011-12-31  2:21                 ` Nikunj A Dadhania
2012-01-02  4:20                   ` Nikunj A Dadhania
2012-01-02  9:39                     ` Avi Kivity
2012-01-02 10:22                       ` Nikunj A Dadhania
2012-01-02  9:37                   ` Avi Kivity
2012-01-02 10:30                     ` Nikunj A Dadhania
2012-01-02 13:33                       ` Avi Kivity
2012-01-04 10:52                     ` Nikunj A Dadhania
2012-01-04 14:41                       ` Avi Kivity
2012-01-04 14:56                         ` Srivatsa Vaddagiri
2012-01-04 17:13                           ` Avi Kivity
2012-01-05  6:57                             ` Nikunj A Dadhania
2012-01-04 16:47                         ` Rik van Riel
2012-01-04 17:16                           ` Avi Kivity
2012-01-04 20:56                             ` Rik van Riel
2012-01-04 21:31                             ` Peter Zijlstra
2012-01-04 21:41                               ` Avi Kivity
2012-01-05  9:10                                 ` Ingo Molnar
2012-02-20  8:08                                   ` Nikunj A Dadhania
2012-02-20  8:14                                     ` Ingo Molnar
2012-02-20 10:51                                     ` Peter Zijlstra
2012-02-20 11:53                                       ` Nikunj A Dadhania
2012-02-20 12:02                                         ` Srivatsa Vaddagiri
2012-02-20 12:14                                           ` Peter Zijlstra
2012-01-05  2:10                         ` Nikunj A Dadhania
2011-12-19 15:51 ` Peter Zijlstra
2011-12-19 16:09   ` Alan Cox
2011-12-19 22:10   ` Benjamin Herrenschmidt
2011-12-20  1:56   ` Nikunj A Dadhania
2011-12-20  8:52   ` Jeremy Fitzhardinge

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