lkml.org 
[lkml]   [2007]   [Nov]   [12]   [last100]   RSS Feed
Views: [more markup]  [less markup]  [headers]  [forward] 
 
Messages in this thread
/
FromFrank Seidel <>
SubjectRe: [RFC 13/13] Char: nozomi, cleanup read and write
DateMon, 12 Nov 2007 10:43:41 +0100
On Montag 12 November 2007 08:54:52, you (Adrian Bunk) wrote:
> On Sat, Nov 10, 2007 at 11:04:41PM +0100, Jiri Slaby wrote:
> > Why? Anyway I think this is the case. The body of the then branch is executed at
> > most once, while the else branch each time but last. If you write/read 1002
> > bytes, it means 250:1. ...and it's invoked from interrupt too...
> 
> AFAIK there is no well defined semantics whether likely/unlikely means 
> 10:1 or 10000:1 that is guaranteed to not change during the next
> 10 years.
> 
> Unless there's a measurable difference, it's best to write readable 
> C code and simply leave all optimizations to the compiler.

From my (totally) beginners point of view i would have guessed a chance of
very well below one percent that this condition is true could be called
"unlikely",
but i have to admit this is most probably a much too naive way of thinking,
especially in regards of compiler optimizations.
And in this special case now there are already most calls (about 80 percent)
caught by the switch-case-shortcuts anyway.

So, i'll revert it.

Thanks a lot for your feedback,
Frank	
-
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: 2007-11-12 10:47    [from the cache]
©2003-2008