lkml.org 
[lkml]   [2002]   [Jan]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: likely/unlikely
On Wed, 16 Jan 2002, Craig Christophel wrote:

> > likely/unlikely set the branch prediction values to 99% or 1%
>
>
> So all of the BUG() routines in the kernel would benifit greatly from this.

In the 2.5 kernels this is done when you use the BUG_ON macro that is
defined as follows:

#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)


BTW: Note that likely/unlikely doesn't has any effect for most of us
because __builtin_expect is only available in gcc >= 2.96.


> Craig.

cu
Adrian


-
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: 2005-03-22 13:23    [W:0.051 / U:0.484 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site