lkml.org 
[lkml]   [2002]   [May]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: linux-2.5.18: DRM + cmpxchg issues
george anzinger wrote:
> Keith Whitwell wrote:
>
>>Adam,
>>
>>I expect the answer is that we need to dig out the old one.
>>
>>Previously I don't think the full cmpxchg semantics werere required unless the
>>box is smp -- there's no case where atomic operations are required for
>>hardware interaction, for example. ...
>>
>>Probably this changed with preempt, though, so we need one even on UP boxes...
>>
>>
> I can not think of any reason to need a lock or atomic
> operation because of preempt. Even the management of the
> preempt on/off flags at most requires memory barriers, even
> in SMP boxen. Do you have an example?

No, I was just pointing out grey areas in my own knowledge.

Keith

-
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 13:26    [W:0.045 / U:0.036 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site