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Date: Fri, 9 Feb 2024 12:35:09 +0000
From: Mark Rutland <mark.rutland@arm.com>
To: Nhat Pham <nphamcs@gmail.com>
Cc: linux-kernel@vger.kernel.org, boqun.feng@gmail.com, frederic@kernel.org,
	joel@joelfernandes.org, neeraj.iitr10@gmail.com, paulmck@kernel.org,
	peterz@infradead.org, will@kernel.org
Subject: Re: [PATCH] locking/atomic: scripts: clarify ordering of conditional
 atomics
Message-ID: <ZcYb_U45Jro_MMeJ@FVFF77S0Q05N.cambridge.arm.com>
References: <20240129122250.1086874-1-mark.rutland@arm.com>
 <20240206184005.4125128-1-nphamcs@gmail.com>
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On Tue, Feb 06, 2024 at 10:40:05AM -0800, Nhat Pham wrote:
> Let me bring in some beginners' perspective :)
> 
> For the most part, LGTM! My only comment is regarding the conditional
> atomics with relaxed ordering on success:
> 
> /**
>   * If (@v == @old), atomically updates @v to @new with relaxed ordering.
> + * Otherwise, @v is not modified and no ordering is provided.
> 
> This is technically correct, but it can be confusing. It reads as if
> "relaxed ordering" is much different from no ordering, since we are
> juxtaposing them when we compare what happens when the condition holds
> v.s when it does not.
> 
> This can be potentially confusing to unfamiliar users. I consulted
> with Paul about this, and he suggested this rewording, which I like
> better:
> 
> "Otherwise, @v is not modified and relaxed ordering is provided."

I agree that makes sense, and doing the same in the commit message makes that
simpler and clearer too!

> With something along that line in place:
> Reviewed-by: Nhat Pham <nphamcs@gmail.com>

Thanks; I'll fold the above in for v2.

Mark.