From: David Miller <davem@davemloft.net>
To: tglx@linutronix.de
Cc: torvalds@linux-foundation.org, harvey.harrison@gmail.com,
mingo@elte.hu, akpm@linux-foundation.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] bitops: remove "optimizations"
Date: Tue, 29 Apr 2008 15:58:24 -0700 (PDT) [thread overview]
Message-ID: <20080429.155824.183713623.davem@davemloft.net> (raw)
In-Reply-To: <alpine.LFD.1.10.0804291843550.6003@apollo.tec.linutronix.de>
From: Thomas Gleixner <tglx@linutronix.de>
Date: Tue, 29 Apr 2008 18:51:51 +0200 (CEST)
> The question is, whether it broke things or just unearthed some bug
> hidden elsewhere.
So I did a quick test, just #if 0'ing out the optimization inline
portions of the find_first_bit() code in linux/bitops.h, and forcing
it to always unconditionally call __find_first_bit() fixes the
regression.
Given that others who tested could not find one case where the
optimization cases actually applied, and it's breaking things for me,
my theory is that it's triggering for some obscure case on sparc64 and
thus showing a bug in these optimizations since in practice I'm the
only person to actually test this new code.
next prev parent reply other threads:[~2008-04-29 22:58 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-04-27 20:19 [PATCH] bitops: simplify generic bit finding functions Harvey Harrison
2008-04-27 20:26 ` Linus Torvalds
2008-04-27 20:29 ` Harvey Harrison
2008-04-27 20:36 ` Al Viro
2008-04-27 20:38 ` Harvey Harrison
2008-04-27 20:38 ` Linus Torvalds
2008-04-27 21:02 ` Al Viro
2008-04-28 14:04 ` Thomas Gleixner
2008-04-28 15:10 ` Alexander van Heukelum
2008-04-28 15:58 ` Thomas Gleixner
2008-04-28 16:25 ` Linus Torvalds
2008-04-28 16:47 ` Thomas Gleixner
2008-04-28 16:54 ` Linus Torvalds
2008-04-28 19:26 ` Thomas Gleixner
2008-04-28 19:37 ` Linus Torvalds
2008-04-28 21:55 ` Ingo Molnar
2008-04-29 10:01 ` [PATCH] bitops: remove "optimizations" Thomas Gleixner
2008-04-29 10:03 ` David Miller
2008-04-29 12:34 ` David Miller
2008-04-29 14:20 ` Ingo Molnar
2008-04-29 22:31 ` David Miller
2008-04-29 16:51 ` Thomas Gleixner
2008-04-29 22:58 ` David Miller [this message]
2008-04-29 23:30 ` David Miller
2008-04-28 19:57 ` [PATCH] bitops: simplify generic bit finding functions Andi Kleen
2008-04-28 14:58 ` Alexander van Heukelum
2008-04-28 14:32 ` Alexander van Heukelum
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