lkml.org 
[lkml]   [2006]   [Nov]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [rfc patch] i386: don't save eflags on task switch
Date

> sti is expensive as well; iirc just as expensive on most processors as
> popf,


On K8 STI is 4 cycles.

> although I don't have hard numbers to back this up on hand. An
> _unlikely_ jcc + popf? is better than a sti, for sure, but a likely
> jcc+popf could cost more than a jcc+sti, depending on model.

99.9999% of all restore_flags just need STI.


-Andi
-
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: 2006-11-05 18:03    [W:0.064 / U:0.468 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site