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From: Andrew Murray <>
To: Will Deacon <>
Cc: Arnd Bergmann <>,
	Catalin Marinas <>,
	Mark Rutland <>,,,
Subject: Re: [PATCH] arm64: fix unreachable code issue with cmpxchg
Date: Tue, 10 Sep 2019 15:21:21 +0100	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <20190910074606.45k5m2pkztlpj4nj@willie-the-truck>

On Tue, Sep 10, 2019 at 08:46:07AM +0100, Will Deacon wrote:
> On Mon, Sep 09, 2019 at 10:21:35PM +0200, Arnd Bergmann wrote:
> > On arm64 build with clang, sometimes the __cmpxchg_mb is not inlined
> Hmm. Given that CONFIG_OPTIMIZE_INLINING has also been shown to break
> assignment of local 'register' variables on GCC, perhaps we should just
> disable that option for arm64 (at least) since we don't have any toolchains
> that seem to like it very much! I'd certainly prefer that over playing
> whack-a-mole with __always_inline.

I assume we're referring to stuff such as the following?

Are these breakages limited to the out-of-line hacks made for LL/SC
atomics, or were there other breakages elsewhere?

Now that the out-of-line hacks have gone, I wonder if this is actually
still a problem anymore. In any case isn't the right thing to do there
to add the __always_inline to functions that use the register keyword
in a function currently annotated inline?

I'm happy to look into this if there is likely to be some benefit in


Andrew Murray

> Will

  parent reply	other threads:[~2019-09-10 14:21 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-09 20:21 [PATCH] arm64: fix unreachable code issue with cmpxchg Arnd Bergmann
2019-09-09 21:06 ` Nick Desaulniers
2019-09-09 21:35   ` Nick Desaulniers
2019-09-10  3:42 ` Nathan Chancellor
2019-09-10  7:46 ` Will Deacon
2019-09-10  8:04   ` Arnd Bergmann
2019-09-10 13:24     ` Will Deacon
2019-09-10 13:43       ` Arnd Bergmann
2019-09-10 14:21   ` Andrew Murray [this message]
2019-09-10  9:23 ` Andrew Murray
2019-09-10  9:38   ` Arnd Bergmann
2019-09-10 10:17     ` Masahiro Yamada
2019-09-10 10:24     ` Andrew Murray

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