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Date: Sat, 31 May 2025 09:46:15 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Alessandro Carminati <acarmina@redhat.com>
Cc: linux-kselftest@vger.kernel.org,
	Dan Carpenter <dan.carpenter@linaro.org>,
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	linux-kernel@vger.kernel.org, Mark Rutland <mark.rutland@arm.com>
Subject: Re: [PATCH v5 1/5] bug/kunit: Core support for suppressing warning
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On Fri, May 30, 2025 at 04:01:40PM +0200, Peter Zijlstra wrote:

> I'm not really concerned with performance here, but more with the size
> of the code emitted by WARN_ONCE(). There are a *ton* of WARN sites,
> while only one report_bug() and printk().

We need a new and stronger unlikely(), resulting in the compiler being
forced to split a .cold sub-function/part which lives in .text.unlikely

At that point it becomes less of a concern I suppose. 

AFAIK the only means of achieving that with the current compilers is
doing a manual function split and marking the part __cold -- which is
unfortunate.

At some point GCC explored label attributes, and we were able to mark
labels with cold, but that never really worked / went anywhere.