From: Steven Rostedt <rostedt@goodmis.org>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>,
richard -rw- weinberger <richard.weinberger@gmail.com>,
laijs@cn.fujitsu.com, LKML <linux-kernel@vger.kernel.org>,
user-mode-linux-devel@lists.sourceforge.net,
dvhart@linux.intel.com
Subject: Re: um: WARNING: at kernel/futex.c:786 __unqueue_futex
Date: Thu, 17 Mar 2011 14:43:37 -0400 [thread overview]
Message-ID: <1300387417.16880.399.camel@gandalf.stny.rr.com> (raw)
In-Reply-To: <1300387122.6315.407.camel@edumazet-laptop>
On Thu, 2011-03-17 at 19:38 +0100, Eric Dumazet wrote:
>
>
> My point was that WARN_ON(X) always evaluates X once
>
> And apparently, WARN_ON_SMP(X) doesnt evaluates X iF !SMP
>
> This should be documented, or fixed ;)
My new patch has it documented. I even explain when to use the _SMP()
version, which is mainly for !spin_is_locked() as spin_is_locked()
always returns false, and !0 will trigger the warning.
It can also be used to test values that only exist in SMP.
struct foo {
[...]
#ifdef CONFIG_SMP
int bar;
#endif
};
WARN_ON_SMP(zoo->bar);
We don't want that zoo->bar even evaluated for that case.
-- Steve
next prev parent reply other threads:[~2011-03-17 18:43 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-17 12:25 um: WARNING: at kernel/futex.c:786 __unqueue_futex richard -rw- weinberger
2011-03-17 14:08 ` Steven Rostedt
2011-03-17 14:17 ` richard -rw- weinberger
2011-03-17 14:27 ` richard -rw- weinberger
2011-03-17 14:31 ` Steven Rostedt
2011-03-17 16:55 ` Steven Rostedt
2011-03-17 17:02 ` Eric Dumazet
2011-03-17 17:43 ` Geert Uytterhoeven
2011-03-17 18:22 ` Steven Rostedt
2011-03-17 18:32 ` Steven Rostedt
2011-03-17 18:16 ` Steven Rostedt
2011-03-17 18:25 ` Geert Uytterhoeven
2011-03-17 18:38 ` Steven Rostedt
2011-03-17 18:38 ` Eric Dumazet
2011-03-17 18:43 ` Steven Rostedt [this message]
2011-03-17 17:18 ` richard -rw- weinberger
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