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Re: [PATCH 2/2] locking/mutex,rwsem: Reduce vcpu_is_preempted() calling frequency

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On 02/08/2017 02:05 PM, Peter Zijlstra wrote:
> On Wed, Feb 08, 2017 at 01:00:25PM -0500, Waiman Long wrote:
>> As the vcpu_is_preempted() call is pretty costly compared with other
>> checks within mutex_spin_on_owner() and rwsem_spin_on_owner(), they
>> are done at a reduce frequency of once every 256 iterations.
> That's just disgusting.

I do have some doubt myself on the effectiveness of this patch. Anyway,
it is the first patch that I think is more beneficial.

Cheers,
Longman

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[PATCH 1/2] x86/paravirt: Don't make vcpu_is_preempted() a callee-save function Waiman Long <longman@redhat.com> - 2017-02-08 19:10 +0100
  [PATCH 2/2] locking/mutex,rwsem: Reduce vcpu_is_preempted() calling frequency Waiman Long <longman@redhat.com> - 2017-02-08 19:10 +0100
    Re: [PATCH 2/2] locking/mutex,rwsem: Reduce vcpu_is_preempted()  calling frequency Waiman Long <longman@redhat.com> - 2017-02-08 20:20 +0100
    Re: [PATCH 2/2] locking/mutex,rwsem: Reduce vcpu_is_preempted()  calling frequency Peter Zijlstra <peterz@infradead.org> - 2017-02-08 21:00 +0100
  Re: [PATCH 1/2] x86/paravirt: Don't make vcpu_is_preempted() a  callee-save function Peter Zijlstra <peterz@infradead.org> - 2017-02-08 20:20 +0100
    Re: [PATCH 1/2] x86/paravirt: Don't make vcpu_is_preempted() a  callee-save function Waiman Long <longman@redhat.com> - 2017-02-08 21:50 +0100

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