Re: [PATCH v2 for Xen 4.6 3/4] libxl: enabling XL to set per-VCPU parameters of a domain for RTDS scheduler

From: Chong Li <lichong659@gmail.com>
To: Dario Faggioli <dario.faggioli@citrix.com>
Cc: Chong Li <chong.li@wustl.edu>, Wei Liu <wei.liu2@citrix.com>,
	Ian Campbell <ian.campbell@citrix.com>,
	Sisu Xi <xisisu@gmail.com>,
	George Dunlap <george.dunlap@eu.citrix.com>,
	Ian Jackson <ian.jackson@eu.citrix.com>,
	xen-devel <xen-devel@lists.xen.org>,
	Meng Xu <mengxu@cis.upenn.edu>,
	Dagaen Golomb <dgolomb@seas.upenn.edu>
Subject: Re: [PATCH v2 for Xen 4.6 3/4] libxl: enabling XL to set per-VCPU parameters of a domain for RTDS scheduler
Date: Wed, 17 Jun 2015 10:47:09 -0500	[thread overview]
Message-ID: <CAGHO-ip7r9U+a_4Lsw=0XifgOMGhVirNJ4P=wbZOj5dBK6chnQ@mail.gmail.com> (raw)
In-Reply-To: <1434544330.25170.11.camel@citrix.com>

On Wed, Jun 17, 2015 at 7:32 AM, Dario Faggioli
<dario.faggioli@citrix.com> wrote:
> On Wed, 2015-06-17 at 13:08 +0100, Ian Campbell wrote:
>> On Tue, 2015-06-09 at 18:18 +0200, Dario Faggioli wrote:
>> > On Mon, 2015-06-08 at 15:55 -0500, Chong Li wrote:
>> > > On Mon, Jun 8, 2015 at 10:56 AM, Dario Faggioli
>> >
>
>> For set overall I don't really think it matters too much if it sets
>> everything (i..e all vcpus and the defaults) so long as is a documented
>> effect of the API -- anyone who adds per-vcpu support would then be
>> aware of this and can adjust their code accordingly.
>>
> Exactly. Personally, I think I'd make per-domain set behave
> consistently, and hence use it for set the default.
>
>> For get I think saying it returns the defaults used for vcpus which
>> don't have something more explicit set is perfectly fine and doesn't
>> pose an upgrade wrinkle, since only those who are aware of the vcpu
>> settings would care about the distinction.
>>
> As said, I like this, great idea.
>
> Chong, what do you think? Can you make this happen?

I like this design, too. Will make it happen soon.
Thanks for these feedbacks.

Chong
>
> Regards,
> Dario
> --
> <<This happens because I choose it to happen!>> (Raistlin Majere)
> -----------------------------------------------------------------
> Dario Faggioli, Ph.D, http://about.me/dario.faggioli
> Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK)

-- 
Chong Li
Department of Computer Science and Engineering
Washington University in St.louis