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From: Dario Faggioli <dfaggioli@suse.com>
To: Meng Xu <xumengpanda@gmail.com>
Cc: xen-devel <xen-devel@lists.xenproject.org>,
	Andrii Anisov <andrii_anisov@epam.com>
Subject: Re: RTDS with extra time issue
Date: Mon, 12 Feb 2018 11:17:18 +0100	[thread overview]
Message-ID: <1518430638.16540.17.camel@suse.com> (raw)
In-Reply-To: <CAENZ-+k63FbKdfvaxxEb9UD0F=BQ-g=f1d=uR_VEEOBHr262Dg@mail.gmail.com>


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On Fri, 2018-02-09 at 23:53 -0500, Meng Xu wrote:
> > 
> > Perhaps Meng has some more ideas on this as well. :-)
> 
> If the RT VCPU has only one RT task on it, we can synchronize the
> release time of the VCPU and that of the RT task. In other words, the
> release offset of both the VCPU and the RT task are the same in terms
> of the wall clock. Then we can assign the task's parameter to the
> VCPU
> and guarantee the task has no deadline miss if the VCPU has no
> deadline miss.
> However, this observation only works when the assumption that one
> VCPU
> has only one task in the RT domain. I'm not sure how practical it is
> because the observation cannot be generalized for multiple tasks on
> one VCPU.
> 
> Andrii and Dario,
> Do you think the assumption that one VCPU runs only one RT task is
> reasonable in practice?
> If it is, is there some use cases for this assumption?
> 
Well, I'll let Andrii reply, but honestly, I don't think it is.

See, for instance, the fact that DomR has only 1 vCPU, so I find it
unlikely that the only thing that run there is *just* *one* real-time
task. :-/

Regards,
Dario
-- 
<<This happens because I choose it to happen!>> (Raistlin Majere)
-----------------------------------------------------------------
Dario Faggioli, Ph.D, http://about.me/dario.faggioli
Software Engineer @ SUSE https://www.suse.com/

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  reply	other threads:[~2018-02-12 10:17 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-09 12:20 RTDS with extra time issue Andrii Anisov
2018-02-09 12:25 ` Andrii Anisov
2018-02-09 13:18 ` Dario Faggioli
2018-02-09 15:03   ` Andrii Anisov
2018-02-09 15:18     ` Dario Faggioli
2018-02-09 15:36       ` Meng Xu
2018-02-09 15:56         ` Andrii Anisov
2018-02-09 17:51           ` Meng Xu
2018-02-10  0:14             ` Dario Faggioli
2018-02-10  4:53               ` Meng Xu
2018-02-12 10:17                 ` Dario Faggioli [this message]
2018-02-12 11:08                   ` Andrii Anisov
2018-02-12 14:52                     ` Meng Xu
2018-02-12 10:38                 ` Andrii Anisov
2018-02-12 10:20       ` Andrii Anisov
2018-02-12 18:44         ` Andrii Anisov
2018-02-16 18:37           ` Dario Faggioli
2018-02-20 11:34             ` Andrii Anisov
2018-02-22 17:53               ` Dario Faggioli
2018-02-26 12:00                 ` Andrii Anisov
2018-02-09 15:34 ` Meng Xu
2018-02-09 15:53   ` Andrii Anisov
2018-02-09 16:04   ` Andrii Anisov
2018-02-09 17:53     ` Meng Xu
2018-02-09 18:07       ` Andrii Anisov

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