lkml.org 
[lkml]   [2006]   [May]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC/PATCH] Make powerpc64 use __thread for per-cpu variables
I wrote:

> Hmmm... Would it be sufficient to use a RELOC_HIDE in __get_cpu_var,
> like this?
>
> #define __get_cpu_var(x) (*(RELOC_HIDE(&per_cpu__##x, 0)))

But that won't work because the compiler can still cache &per_cpu__x.
I guess I have to do this:

#define __get_cpu_var(var, cpu) \
(*(__typeof__(&per_cpu__##var))({ \
void *__ptr; \
asm("addi %0,13,per_cpu__"#var"@tprel" \
: "=r" (__ptr)); \
__ptr; \
}))

That means we lose the possible optimization of combining the addi
into a following load or store. Bah. However, I guess it's still
better than what we do at the moment.

Paul.
-
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 01:47    [W:0.099 / U:0.300 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site