From: Rik van Riel <riel@redhat.com>
To: Avi Kivity <avi@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Ingo Molnar <mingo@elte.hu>,
Anthony Liguori <aliguori@linux.vnet.ibm.com>
Subject: Re: [RFC PATCH 3/3] kvm: use yield_to instead of sleep in kvm_vcpu_on_spin
Date: Thu, 09 Dec 2010 12:07:32 -0500 [thread overview]
Message-ID: <4D010CD4.4020400@redhat.com> (raw)
In-Reply-To: <4D00AF3C.40603@redhat.com>
On 12/09/2010 05:28 AM, Avi Kivity wrote:
> On 12/09/2010 12:38 AM, Rik van Riel wrote:
>>
>>>> - /* Sleep for 100 us, and hope lock-holder got scheduled */
>>>> - expires = ktime_add_ns(ktime_get(), 100000UL);
>>>> - schedule_hrtimeout(&expires, HRTIMER_MODE_ABS);
>>>> + if (first_round&& last_boosted_vcpu == kvm->last_boosted_vcpu) {
>>>> + /* We have not found anyone yet. */
>>>> + first_round = 0;
>>>> + goto again;
>>>
>>> Need to guarantee termination.
>>
>> We do that by setting first_round to 0 :)
>>
>> We at most walk N+1 VCPUs in a VM with N VCPUs, with
>> this patch.
>>
>
> Right. May be clearer by using a for () loop instead of the goto.
And open coding kvm_for_each_vcpu ?
Somehow I suspect that won't add to clarity...
--
All rights reversed
next prev parent reply other threads:[~2010-12-09 17:07 UTC|newest]
Thread overview: 60+ 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
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 [this message]
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
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