lkml.org 
[lkml]   [2006]   [Sep]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Sysenter crash with Nested Task Bit set

* Andi Kleen <ak@suse.de> wrote:

> > #define switch_to(prev,next,last) do { \
> > unsigned long esi,edi; \
> > - asm volatile("pushl %%ebp\n\t" \
> > + asm volatile("pushfl\n\t" /* Save flags */ \
> > + "pushl %%ebp\n\t" \
>
> We used to do that pushfl/popfl some time ago, but Ben removed it
> because it was slow on P4. Ok, nobody thought of that case back then.

I _should_ have thought of that though, because when this change was
done originally i had to reintroduce it both for exec-shield and for
-rt, so apparently it must have triggered in certain circumstances - i
just didnt notice the reason. (but recent exec-shield and -rt patches
dont have this revert, so the condition must have gone away. But it was
a long time ago.)

Ingo
-
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: 2006-09-18 17:35    [W:0.060 / U:0.112 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site