Re: [PATCH v5 1/6] locking/pvqspinlock: Unconditional PV kick with _Q_SLOW_VAL

[Waiman Long]

On 08/08/2015 02:02 AM, Peter Zijlstra wrote:
> On Fri, Aug 07, 2015 at 11:17:56PM -0400, Waiman Long wrote:
> > If _Q_SLOW_VAL has been set, the vCPU state must have been vcpu_hashed.
> > The extra check at the end of __pv_queued_spin_unlock() is unnecessary
> > and so is removed.
> This is half the patch it should be.
>
> Because if the load is not needed, then the store is not either, and
> then there's the comments to update.

Sorry for the late reply.


That is true. Setting state to vcpu_hashed in pv_wait_head() isn't 
really necessary. I kept it there for consistency sake as the state may 
be set to vcpu_hashed in pv_kick_node(). We can certainly take that out.

BTW, could you also review the other patches when you have time? I am 
coming to the LinuxCon/Plumbers next week. Hopefully, I can chat with 
you again.

Cheers,
Longman

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