[Libva] memcpy VA image buffer, very poor performance!

[hank peng]

Hi:
I use vaMapBuffer function to map VA image buffer, then copy data from
it to my allocated memory using malloc function. I found it's
performace is very poor, then, I do a test program on same platform
between two allocated memory whose size is same as VA image buffer,
the performance is much better, Is there any difference between the VA
image mapped buffer and normal buffer allocated by malloc function?

-- 
The simplest is not all best but the best is surely the simplest!