All of lore.kernel.org
 help / color / mirror / Atom feed
From: Rik van Riel <riel@redhat.com>
To: Hillf Danton <dhillf@gmail.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	Avi Kiviti <avi@redhat.com>,
	Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Mike Galbraith <efault@gmx.de>,
	Chris Wright <chrisw@sous-sol.org>
Subject: Re: [RFC -v3 PATCH 2/3] sched: add yield_to function
Date: Tue, 04 Jan 2011 11:54:06 -0500	[thread overview]
Message-ID: <4D2350AE.60302@redhat.com> (raw)
In-Reply-To: <AANLkTim8zmhKjPs-fVdR=65VPd6hybD8HA8pKEyKzm13@mail.gmail.com>

On 01/04/2011 11:51 AM, Hillf Danton wrote:

>> Wouldn't that break for FIFO and RR tasks?
>>
>> There's a reason all the scheduler folks wanted a
>> per-class yield_to_task function :)
>>
>
> Where is the yield_to callback in the patch for RT schedule class?
> If @p is RT, what could you do?

If the user chooses to overcommit the CPU with realtime
tasks, the user cannot expect realtime response.

For realtime, I have not implemented the yield_to callback
at all because it would probably break realtime semantics
and I assume people will not overcommit the CPU with realtime
tasks anyway.

I could see running a few realtime guests on a system, with
the number of realtime VCPUs not exceeding the number of
physical CPUs.

-- 
All rights reversed

  reply	other threads:[~2011-01-04 16:54 UTC|newest]

Thread overview: 53+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-01-03 21:26 [RFC -v3 PATCH 0/3] directed yield for Pause Loop Exiting Rik van Riel
2011-01-03 21:27 ` [RFC -v3 PATCH 1/3] kvm: keep track of which task is running a KVM vcpu Rik van Riel
2011-01-03 21:29 ` [RFC -v3 PATCH 2/3] sched: add yield_to function Rik van Riel
2011-01-04  1:51   ` Mike Galbraith
2011-01-04  6:14   ` KOSAKI Motohiro
2011-01-04 12:03     ` Avi Kivity
2011-01-05  2:39       ` KOSAKI Motohiro
2011-01-05  8:35         ` Avi Kivity
2011-01-05  8:40           ` KOSAKI Motohiro
2011-01-05  9:08             ` Avi Kivity
2011-01-05  9:30               ` KOSAKI Motohiro
2011-01-05  9:34                 ` Avi Kivity
2011-01-05 10:24             ` Peter Zijlstra
2011-01-05 10:04         ` Peter Zijlstra
2011-01-04 17:16     ` Peter Zijlstra
2011-01-05  3:17       ` KOSAKI Motohiro
2011-01-04 14:28   ` Hillf Danton
2011-01-04 16:41   ` Hillf Danton
2011-01-04 16:44     ` Rik van Riel
2011-01-04 16:51       ` Hillf Danton
2011-01-04 16:51         ` Hillf Danton
2011-01-04 16:54         ` Rik van Riel [this message]
2011-01-04 17:02           ` Hillf Danton
2011-01-04 17:08         ` Peter Zijlstra
2011-01-04 17:12           ` Hillf Danton
2011-01-04 17:22             ` Peter Zijlstra
2011-01-04 17:53           ` Rik van Riel
2011-01-04 18:05             ` Peter Zijlstra
2011-01-04 18:04   ` Peter Zijlstra
2011-01-04 18:53     ` Mike Galbraith
2011-01-05 16:57     ` Mike Galbraith
2011-01-05 17:04       ` Peter Zijlstra
2011-01-05 17:23         ` Mike Galbraith
2011-01-07  5:29         ` Mike Galbraith
2011-01-13  3:02           ` Rik van Riel
2011-01-13  3:26             ` Mike Galbraith
2011-01-13  5:08               ` Rik van Riel
2011-01-06 14:33       ` Hillf Danton
2011-01-05 17:10     ` Avi Kivity
2011-01-05 17:15       ` Peter Zijlstra
2011-01-05 17:19         ` Avi Kivity
2011-01-05 17:28           ` Peter Zijlstra
2011-01-05 17:35             ` Avi Kivity
2011-01-05 17:39               ` Peter Zijlstra
2011-01-06  3:49                 ` Tejun Heo
2011-01-03 21:30 ` [RFC -v3 PATCH 3/3] Subject: kvm: use yield_to instead of sleep in kvm_vcpu_on_spin Rik van Riel
2011-01-04  6:42 ` [RFC -v3 PATCH 0/3] directed yield for Pause Loop Exiting Mike Galbraith
2011-01-04  9:09   ` Avi Kivity
2011-01-04 10:32     ` Mike Galbraith
2011-01-04 10:35       ` Avi Kivity
2011-01-04  9:14 ` Avi Kivity
2011-01-04 10:26   ` Mike Galbraith
2011-01-04 17:20     ` Peter Zijlstra

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4D2350AE.60302@redhat.com \
    --to=riel@redhat.com \
    --cc=a.p.zijlstra@chello.nl \
    --cc=avi@redhat.com \
    --cc=chrisw@sous-sol.org \
    --cc=dhillf@gmail.com \
    --cc=efault@gmx.de \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=vatsa@linux.vnet.ibm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.