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Subject: Re: [PATCH v2 3/5] locking/qspinlock: Introduce CNA into the slow
 path of qspinlock
From:   Alex Kogan <alex.kogan@oracle.com>
In-Reply-To: <20190605204003.GC3402@hirez.programming.kicks-ass.net>
Date:   Thu, 6 Jun 2019 11:21:48 -0400
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        Steven Sistare <steven.sistare@oracle.com>,
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To:     Peter Zijlstra <peterz@infradead.org>
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>> 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?
>>=20
>> We still need a config option (something like NUMA_AWARE_SPINLOCKS) =
to
>> enable CNA patching under this config only, correct?
>=20
> 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.

Thanks!
=E2=80=94 Alex