From: David Howells <dhowells@redhat.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: dhowells@redhat.com, Eric Dumazet <eric.dumazet@gmail.com>,
adobriyan@gmail.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Reduce the number of expensive division instructions done by _parse_integer()
Date: Thu, 09 Feb 2012 19:23:03 +0000 [thread overview]
Message-ID: <26494.1328815383@redhat.com> (raw)
In-Reply-To: <CA+55aFzePmV8st-PaQeO_eS05CUWQePDoQsXdd=HaiLffz+wxw@mail.gmail.com>
Linus Torvalds <torvalds@linux-foundation.org> wrote:
> 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?
Just by looking at the code. I can't think of anything particularly where
this is likely to be encountered in a critical path.
David
prev parent reply other threads:[~2012-02-09 19:23 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-09 15:48 [PATCH] Reduce the number of expensive division instructions done by _parse_integer() David Howells
2012-02-09 16:28 ` Eric Dumazet
2012-02-09 16:42 ` Eric Dumazet
2012-02-09 16:58 ` Linus Torvalds
2012-02-09 17:08 ` Linus Torvalds
2012-02-09 17:46 ` David Howells
2012-02-09 17:56 ` Linus Torvalds
2012-02-09 18:07 ` David Howells
2012-02-09 18:08 ` Linus Torvalds
2012-02-09 18:50 ` David Howells
2012-02-09 19:14 ` Linus Torvalds
2012-02-10 13:50 ` Alexey Dobriyan
2012-02-09 19:23 ` David Howells [this message]
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