lkml.org 
[lkml]   [2003]   [Apr]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [BUG] 2.5.65: Caching MSR_IA32_SYSENTER_CS kills dosemu

On 1 Apr 2003, Robert Love wrote:
>
> Actually, do they do disable preemption - if they do not, something is
> broken.

Ok, I was too lazy to check. Anyway, the test-patch is worth trying, since
one of the areas fixed had no pre-emption protection regardless (ie it
used just a plain "smp_processor_id()"), and the patch should be
technically equivalent (just uglier) to a proper get_cpu().

> Because, even on UP, preemption can lead to a race over a variable that
> has no locking because its per-CPU. But it would need locking
> otherwise, and thus we do need to disable preemption.

Yes, that was certainly the case here.

Linus

-
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: 2005-03-22 13:34    [W:0.270 / U:0.312 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site