Re: [PATCH v1 2/2] x86/hyperv: make HvNotifyLongSpinWait hypercall

[Peter Zijlstra]

On Thu, Nov 01, 2018 at 11:20:21AM +0800, Yi Sun wrote:
> On 18-10-31 18:15:39, Peter Zijlstra wrote:

> > So Yi, are you actually seeing a problem? If so, can you give details?
> 
> Where does the patch come from? I cannot find it through google.

What patch!? The one I posted:

  https://lkml.kernel.org/r/20181031141030.GB13219@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

I made that up real quick.

> Per Waiman's comment, it seems not suitable to call vcpu_is_preempted()
> in pv_wait_head_or_lock(). So, we cannot make HvSpinWaitInfo notification
> through vcpu_is_preempted() for such case. Based on that, I suggest to
> add one more callback function in pv_lock_ops.

We're not doing anything until you can show a problem. If it ain't
broken, don't fix it etc..

> BTW, which performance test do you suggest? I am trying to test it by
> AIM7.

Waiman?