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From: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Rik van Riel <riel@redhat.com>,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	Avi Kiviti <avi@redhat.com>, Ingo Molnar <mingo@elte.hu>,
	Anthony Liguori <aliguori@linux.vnet.ibm.com>
Subject: Re: [RFC PATCH 2/3] sched: add yield_to function
Date: Fri, 3 Dec 2010 19:00:57 +0530	[thread overview]
Message-ID: <20101203133056.GF27994@linux.vnet.ibm.com> (raw)
In-Reply-To: <1291382619.32004.2124.camel@laptop>

On Fri, Dec 03, 2010 at 02:23:39PM +0100, Peter Zijlstra wrote:
> Right, so another approach might be to simply swap the vruntime between
> curr and p.

Can't that cause others to stave? For ex: consider a cpu p0 having these tasks:

p0 ->  A0 B0 A1

A0/A1 have entered some sort of AB<->BA spin-deadlock, as a result A0 wants to
direct yield to A1 which wants to direct yield to A0. If we keep swapping their
runtimes, can't it starve B0?

- vatsa



  reply	other threads:[~2010-12-03 13:31 UTC|newest]

Thread overview: 65+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-12-02 19:41 [RFC PATCH 0/3] directed yield for Pause Loop Exiting Rik van Riel
2010-12-02 19:43 ` [RFC PATCH 1/3] kvm: keep track of which task is running a KVM vcpu Rik van Riel
2010-12-03  1:18   ` Chris Wright
2010-12-03 14:50     ` Rik van Riel
2010-12-03 15:55       ` Chris Wright
2010-12-05 12:40       ` Avi Kivity
2010-12-03 12:17   ` Srivatsa Vaddagiri
2010-12-03 14:16     ` Rik van Riel
2010-12-05 12:59       ` Avi Kivity
2010-12-02 19:44 ` [RFC PATCH 2/3] sched: add yield_to function Rik van Riel
2010-12-03  0:50   ` Chris Wright
2010-12-03 18:27     ` Rik van Riel
2010-12-03 19:30       ` Chris Wright
2010-12-03 21:30       ` Peter Zijlstra
2010-12-03  5:54   ` Mike Galbraith
2010-12-03 13:46     ` Srivatsa Vaddagiri
2010-12-03 14:45       ` Mike Galbraith
2010-12-03 14:48         ` Rik van Riel
2010-12-03 15:09           ` Mike Galbraith
2010-12-03 15:35             ` Rik van Riel
2010-12-03 16:20               ` Srivatsa Vaddagiri
2010-12-03 17:09                 ` Rik van Riel
2010-12-03 17:29                   ` Srivatsa Vaddagiri
2010-12-03 17:33                     ` Rik van Riel
2010-12-03 17:45                       ` Srivatsa Vaddagiri
2010-12-03 20:05               ` Mike Galbraith
2010-12-03 21:26             ` Peter Zijlstra
2010-12-03 13:23   ` Peter Zijlstra
2010-12-03 13:30     ` Srivatsa Vaddagiri [this message]
2010-12-03 14:03       ` Peter Zijlstra
2010-12-03 14:06         ` Srivatsa Vaddagiri
2010-12-03 14:10           ` Srivatsa Vaddagiri
2010-12-03 21:23             ` Peter Zijlstra
2010-12-04 13:02               ` Rik van Riel
2010-12-10  4:34           ` Rik van Riel
2010-12-10  8:39             ` Srivatsa Vaddagiri
2010-12-10 14:55               ` Rik van Riel
2010-12-08 17:55     ` Rik van Riel
2010-12-08 20:00       ` Peter Zijlstra
2010-12-08 20:04         ` Peter Zijlstra
2010-12-08 22:59         ` Rik van Riel
2010-12-02 19:45 ` [RFC PATCH 3/3] kvm: use yield_to instead of sleep in kvm_vcpu_on_spin Rik van Riel
2010-12-03  2:24   ` Chris Wright
2010-12-05 12:58     ` Avi Kivity
2010-12-05 12:56   ` Avi Kivity
2010-12-08 22:38     ` Rik van Riel
2010-12-09 10:28       ` Avi Kivity
2010-12-09 17:07         ` Rik van Riel
2010-12-11  7:27           ` Avi Kivity
2010-12-02 22:41 ` [RFC PATCH 0/3] directed yield for Pause Loop Exiting Chris Wright
2010-12-05 13:02   ` Avi Kivity
2010-12-10  5:03 ` Balbir Singh
2010-12-10 14:54   ` Rik van Riel
2010-12-11  7:31   ` Avi Kivity
2010-12-11 13:57     ` Balbir Singh
2010-12-13 11:57       ` Avi Kivity
2010-12-13 12:39         ` Balbir Singh
2010-12-13 12:42           ` Avi Kivity
2010-12-13 17:02       ` Rik van Riel
2010-12-14  9:25         ` Balbir Singh
  -- strict thread matches above, loose matches on Subject: below --
2011-01-02 11:43 [RFC PATCH 2/3] sched: add yield_to function Hillf Danton
2011-01-02 17:19 ` Rik van Riel
2011-01-03  4:18   ` Hillf Danton
2011-01-03  5:04     ` Rik van Riel
2011-01-04 12:44       ` Hillf Danton

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