set_var_mtrr(0, 0x08000000, 0x10000000, MTRR_TYPE_WRBACK);
Hm.. doesn't the base address need at least an alignment of size?
Yes. Thanks.
Have you tried disabling caching completely for the area?
Not here, I did before. I was hoping that caching would avoid the alignment issues I've been seeing.
// Try to force the values out of the cache.
If you are trying to avoid the accesses from being cached, they need to cross a cache line.
I wasn't trying to cross a cache line. I was trying to write to the same cache line enough times that it would force it to write it back.
The above accesses would imho not cross a cache line, unless a cache line on opteron is as small as 8 byte, which I find hard to believe.
You're right.
Thanks, Myles