lkml.org 
[lkml]   [2006]   [Oct]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] Fix WARN_ON / WARN_ON_ONCE regression
From
Date
On Tue, 2006-10-10 at 09:04 -0400, Steven Rostedt wrote:

>
> Holy crap! I wonder where else in the kernel gcc is doing this. (of
> course I'm using gcc4 so I don't know). Is there another gcc attribute
> to actually tell gcc that a variable is really mostly read only (besides
> placing it in a mostly read only elf section)?
>
> What was wrong with the original WARN_ON_ONCE with
>
> if (unlikely(condition) && __warn_once)
>
> This didn't have the cache crash problem too, did it?
> I don't have a gcc3 around to test.

In the original WARN_ON_ONCE, gcc3 only writes to __warn_once when
(condition) is true. So it does not cause cache bouncing by always
writing to __warn_once.

Tim
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-10-10 18:35    [W:0.051 / U:1.088 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site