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From: Duncan Sands <baldrick@wanadoo.fr>
To: "Martin J. Bligh" <mbligh@aracnet.com>, Andrew Morton <akpm@digeo.com>
Subject: Re: BUGed to death
Date: Mon, 14 Apr 2003 22:40:41 +0200
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On Monday 14 April 2003 22:19, Martin J. Bligh wrote:
> Seems all these bug checks are fairly expensive. I can get 1%
> back on system time for kernel compiles by changing BUG to
> "do {} while (0)" to make them all compile away. Profiles aren't
> very revealing though ... seems to be within experimental error ;-(
>
> I was pondering CONFIG_RUN_WILD_NAKED_AND_FREE, but maybe we can
> just nail a few of the hottest path ones instead (I think you did
> a couple already recently). I guess that suggestion isn't much
> use without more profile data though ;-)

You would think that the compiler would consider a branch leading to
ud2 (i.e. BUG()) to be "unlikely", but it doesn't seem to.  Maybe some
improvement can be made there.

All the best,

Duncan.

PS: gcc 3.2.3