linux-kernel - Re: [PATCH] x86: page: get

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Message-ID: <1301216279.15393.9.camel@debian>
Date:	Sun, 27 Mar 2011 11:57:59 +0300
From:	Maksym Planeta <mcsim.planeta@...il.com>
To:	Ingo Molnar <mingo@...e.hu>
Cc:	tglx@...utronix.de, kernel-janitors@...r.kernel.org,
	mingo@...hat.com, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] x86: page: get_order() optimization

On Wed, 23/03/2011 at 11:07 +0100, Ingo Molnar wrote:

> Ok, that's certainly a nice optimization.

Thanks, I rewrote patch according to your observations.

> One detail: in many cases 'size' is a constant. Have you checked recent GCC, 
> does it turn the generic version of get_order() into a loop even for constants, 
> or is it able does it perhaps recognize the pattern and precompute the result?

Yes, gcc precomputes the result, so I added case for constants.

> With no #ifdefs in get_order().

And removed #ifdefs from get_order().

-- 
Thanks,

Maksym Planeta

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