Re: [PATCH v2 3/5] locking/qspinlock: Introduce CNA into the slow path of qspinlock

From: Alex Kogan
Date: Thu Jun 06 2019 - 11:27:42 EST

>> Also, the paravirt code is under arch/x86, while CNA is generic (not
>> x86-specific). Do you still want to see CNA-related patching residing
>> under arch/x86?
>> We still need a config option (something like NUMA_AWARE_SPINLOCKS) to
>> enable CNA patching under this config only, correct?
> There is the static_call() stuff that could be generic; I posted a new
> version of that today (x86 only for now, but IIRC there's arm64 patches
> for that around somewhere too).

The static_call technique appears as the more desirable long-term approach, but I think it would be prudent to keep the patches decoupled for now so we can move forward with less entanglements.
So unless anyone objects, we will work on plugging into the existing patching for pv.
And we will keep that code under arch/x86, but will be open for any suggestion to move it elsewhere.

â Alex