linux-kernel - Re: [PATCH] Reduce the number of expensive division instructions done by _parse

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Message-ID: <CA+55aFzePmV8st-PaQeO_eS05CUWQePDoQsXdd=HaiLffz+wxw@mail.gmail.com>
Date:	Thu, 9 Feb 2012 11:14:55 -0800
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	David Howells <dhowells@...hat.com>
Cc:	Eric Dumazet <eric.dumazet@...il.com>, adobriyan@...il.com,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] Reduce the number of expensive division instructions done
 by _parse_integer()

Btw, what was the load that you noticed this on?

Because quite frankly, I think we only support bases 8/10/16 in the
kernel, and if you really have some case where this all is expensive,
it might be better to simply have three different functions for the
three bases. That would turn the multiplies into constants too, and
also simplify the character tests.

That said, I can't really see how this could ever be all that hot a
function. Did you ever see it in a profile, or was this all just from
looking at the code?

                         Linus
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