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Date:   Thu, 14 May 2020 16:13:44 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Marco Elver <elver@google.com>
Cc:     Will Deacon <will@kernel.org>, LKML <linux-kernel@vger.kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        "Paul E. McKenney" <paulmck@kernel.org>,
        Ingo Molnar <mingo@kernel.org>,
        Dmitry Vyukov <dvyukov@google.com>
Subject: Re: [PATCH v5 00/18] Rework READ_ONCE() to improve codegen
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On Wed, May 13, 2020 at 03:58:30PM +0200, Marco Elver wrote:
> On Wed, 13 May 2020 at 15:24, Peter Zijlstra <peterz@infradead.org> wrote:

> > Also, could not this compiler instrumentation live as a kernel specific
> > GCC-plugin instead of being part of GCC proper? Because in that case,
> > we'd have much better control over it.
> 
> I'd like it if we could make it a GCC-plugin for GCC, but how? I don't
> see a way to affect TSAN instrumentation. FWIW Clang already has
> distinguish-volatile support (unreleased Clang 11).

Ah, I figured not use the built-in TSAN at all, do a complete
replacement of the instrumentation with a plugin. AFAIU plugins are able
to emit instrumentation, but this isn't something I know a lot about.