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* Re: [PATCH RFC v6 10/11] pvqspinlock, x86: Enable qspinlock PV support for KVM
       [not found] ` <1394650498-30118-11-git-send-email-Waiman.Long@hp.com>
@ 2014-03-13 13:59   ` Paolo Bonzini
       [not found]     ` <5322035B.5000205@hp.com>
  0 siblings, 1 reply; 2+ messages in thread
From: Paolo Bonzini @ 2014-03-13 13:59 UTC (permalink / raw)
  To: Waiman Long, Thomas Gleixner, Ingo Molnar, H. Peter Anvin,
	Arnd Bergmann, Peter Zijlstra
  Cc: Jeremy Fitzhardinge, Raghavendra K T, kvm, virtualization,
	Andi Kleen, Michel Lespinasse, Alok Kataria, linux-arch,
	Gleb Natapov, x86, xen-devel, Paul E. McKenney, Scott J Norton,
	Rusty Russell, Steven Rostedt, Chris Wright, Oleg Nesterov,
	Boris Ostrovsky, Aswin Chandramouleeswaran, Chegu Vinod,
	linux-kernel, David Vrabel, Andrew Morton

Il 12/03/2014 19:54, Waiman Long ha scritto:
> @@ -807,8 +889,13 @@ void __init kvm_spinlock_init(void)
>  	if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT))
>  		return;
>
> +#ifdef CONFIG_QUEUE_SPINLOCK
> +	pv_lock_ops.kick_cpu = kvm_kick_cpu_type;
> +	pv_lock_ops.hibernate = kvm_hibernate;
> +#else
>  	pv_lock_ops.lock_spinning = PV_CALLEE_SAVE(kvm_lock_spinning);
>  	pv_lock_ops.unlock_kick = kvm_unlock_kick;
> +#endif

This should also disable the unfair path.

Paolo


^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [PATCH RFC v6 10/11] pvqspinlock, x86: Enable qspinlock PV support for KVM
       [not found]       ` <5322C0F7.2090604@redhat.com>
@ 2014-03-17 17:47         ` Waiman Long
  0 siblings, 0 replies; 2+ messages in thread
From: Waiman Long @ 2014-03-17 17:47 UTC (permalink / raw)
  To: Paolo Bonzini
  Cc: Jeremy Fitzhardinge, Raghavendra K T, kvm, Peter Zijlstra,
	virtualization, Andi Kleen, H. Peter Anvin, Michel Lespinasse,
	Alok Kataria, linux-arch, Gleb Natapov, x86, Ingo Molnar,
	xen-devel, Paul E. McKenney, Arnd Bergmann, Scott J Norton,
	Steven Rostedt, Chris Wright, Thomas Gleixner,
	Aswin Chandramouleeswaran, Chegu Vinod, Boris Ostrovsky,
	Oleg Nesterov, linux-kernel

On 03/14/2014 04:42 AM, Paolo Bonzini wrote:
> Il 13/03/2014 20:13, Waiman Long ha scritto:
>>>>
>>>
>>> This should also disable the unfair path.
>>>
>>> Paolo
>>>
>>
>> The unfair lock uses a different jump label and does not require any
>> special PV ops. There is a separate init function for that.
>
> Yeah, what I mean is that the patches that enable paravirtualization 
> should also take care of decreasing the unfair-lock jump label when 
> paravirtualization is enabled.
>
> Paolo

As there are people who don't like unfair lock at all, I prefer to give 
them the option to turn this on or off instead of forcing them to always 
use unfair lock in a PV guest.

-Longman

^ permalink raw reply	[flat|nested] 2+ messages in thread

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     [not found] ` <1394650498-30118-11-git-send-email-Waiman.Long@hp.com>
2014-03-13 13:59   ` [PATCH RFC v6 10/11] pvqspinlock, x86: Enable qspinlock PV support for KVM Paolo Bonzini
     [not found]     ` <5322035B.5000205@hp.com>
     [not found]       ` <5322C0F7.2090604@redhat.com>
2014-03-17 17:47         ` Waiman Long

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