lkml.org 
[lkml]   [2006]   [Jul]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 1/2] x86-64 TIF flags for debug regs and io bitmap in ctxsw
From
Date
> -		}
> - }
> + if (unlikely((task_thread_info(next_p)->flags & _TIF_WORK_CTXSW))
> + || test_tsk_thread_flag(prev_p, TIF_IO_BITMAP))
> + __switch_to_xtra(prev_p, next_p, tss);

well isn't this replacing an if() (which isn't cheap but also not
expensive, due to unlikely()) with an atomic operation (which *is*
expensive) ?

That to me doesn't make this sound like an actual win....


-
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: 2006-07-04 09:54    [W:0.045 / U:0.124 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site