lkml.org 
[lkml]   [2010]   [Feb]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: x86 - cpu_relax - why nop vs. pause?
Michael Breuer wrote:
> Just to move away from this... totally perplexed, I retested a bit.
> Seems something else had gone wrong causing me to try 'rep;pause' vs.
> 'pause'. The resulting opcode is f3 f3 90, as noted above.
>
> I do see what seems to be a small but noticeable performance improvement
> - no idea if there's a downside, and also no idea what f3 f3 90 does vs.
> f3 90. Might be something interesting, or maybe not.

Alignment? IOW what happens if you use eg "nop; rep; nop;" or "rep; nop; nop;"?


\
 
 \ /
  Last update: 2010-02-08 14:35    [W:0.120 / U:0.444 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site