linux-kernel - Re: [PATCH 00/10] jump label: introduce very

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Date:	Wed, 22 Feb 2012 09:36:03 -0500
From:	Steven Rostedt <rostedt@...dmis.org>
To:	Mathieu Desnoyers <mathieu.desnoyers@...icios.com>
Cc:	Ingo Molnar <mingo@...e.hu>, "H. Peter Anvin" <hpa@...or.com>,
	Jason Baron <jbaron@...hat.com>, a.p.zijlstra@...llo.nl,
	davem@...emloft.net, ddaney.cavm@...il.com,
	akpm@...ux-foundation.org, linux-kernel@...r.kernel.org,
	Linus Torvalds <torvalds@...ux-foundation.org>
Subject: Re: [PATCH 00/10] jump label: introduce very_[un]likely + cleanups
 + docs

The bike shed is getting really dark.

On Wed, 2012-02-22 at 09:20 -0500, Mathieu Desnoyers wrote:
>  
> [...]
> One possible naming that might be a good fit:
> 
> - read_always_likely()
> - read_always_unlikely()
> - read_always_branch()
> 
> I think it is important to convey both that it is expected to be always
> read, pretty much never updated, and the bias, or absence of bias.

That actually looks even more confusing. "read_always"? What the hell is
that?

> 
> I also _like_ to have a relatively long name here, because the update
> cost is so high that someone should really think before using this
> facility. In my opinion, it's not "just" a stronger likely/unlikely.

Then make it what it is (with a long name...)

	if (jump_label_likely())

	if (jump_label_unlikely())

That's probably the least confusing of the names. And for the cases we
don't care:

	if (jump_label_branch())

The above is the most descriptive and I would say the least confusing.
Someone on IRC said that they wish it had jump_label in the name. As
they see there's a "CONFIG_JUMP_LABEL" it tells us where those jump
labels are used.

Need to go and knock down the bike shed now.

-- Steve


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