linux-kernel - Re: [tip:x86/cpu] x86/cpu: Strip any /proc/ cpuinfo model name field whitespace

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Message-ID: <20150528183321.GD31800@pd.tnic>
Date:	Thu, 28 May 2015 20:33:21 +0200
From:	Borislav Petkov <bp@...en8.de>
To:	"H. Peter Anvin" <hpa@...or.com>
Cc:	Prarit Bhargava <prarit@...hat.com>, Joe Perches <joe@...ches.com>,
	luto@...capital.net, peterz@...radead.org, dvlasenk@...hat.com,
	torvalds@...ux-foundation.org, imammedo@...hat.com,
	brgerst@...il.com, mingo@...nel.org, dave.hansen@...ux.intel.com,
	fenghua.yu@...el.com, linux-kernel@...r.kernel.org,
	tglx@...utronix.de, bp@...e.de, linux-tip-commits@...r.kernel.org
Subject: Re: [tip:x86/cpu] x86/cpu: Strip any /proc/ cpuinfo model name field
 whitespace

On Thu, May 28, 2015 at 09:57:15AM -0700, H. Peter Anvin wrote:
> Why?!
>
> We are taking about 48 bytes run once per cpu. It isn't worth it to
> optimize, in fact the extra code size hurts more.

I wanted to save us the redundant copying of the exact same bytes.
Because when there's no preceding whitespace, p and q point at the same
thing so we end up doing *p = *p.

OTOH, without the optimization, the code is even simpler.

I can remove it if you wanna - I don't care all that much.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
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