Re: [RFC][PATCH 3/3] locking/qspinlock: Optimize for x86

From: Andrea Parri
Date: Thu Sep 27 2018 - 04:13:26 EST


On Thu, Sep 27, 2018 at 09:59:35AM +0200, Peter Zijlstra wrote:
> On Thu, Sep 27, 2018 at 09:47:48AM +0200, Andrea Parri wrote:
> > > LKMM in particular does _NOT_ deal with mixed sized atomics _at_all_.
> >
> > True, but it is nothing conceptually new to deal with: there're Cat
> > models that handle mixed-size accesses, just give it time.
>
> Sure, but until that time I must not rely on (and thus not use) LKMM for
> qspinlock things.

This is way too generic to be agreed ;D


>
> So while your argument about coherence might be true -- I'll have to
> think about it; litmus tests are out the window.

You trimmed the litmus test I gave you.

Andrea