lkml.org 
[lkml]   [2006]   [May]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [RFC/PATCH] Make powerpc64 use __thread for per-cpu variables
Date
>>> How do you plan to address the compiler optimizing
>> ...
>>> Across the schedule, we may have changed cpus, making the cached
>>> address invalid.
>>
>> Per-cpu variables need to be accessed only with preemption
>> disabled. And the preemption enable/disable operations
>> provide a compiler memory barrier.
>
> No, Richard has a point, it's not the value that is the concern, it's
> the address, which gcc could assume is still valid after a barrier.
> Drat.

Would an asm clobber of GPR13 in the schedule routines (or a wrapper
for them, or whatever) work?


Segher

-
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: 2006-05-11 01:20    [W:0.400 / U:0.080 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site