Re: dcbz not used on ppc64?

Anton Blanchard wrote:

quoted

1) Is it in fact true that ppc64 does not use dcbz in the kernel?
2) If so, why not?  Presumably it would be a win in some cases, otherwise they wouldn't be using it in ppc32.  Is there some other factore in play for ppc64?

include/asm-ppc64/page.h:clear_page() uses it:

Hmm.  As of 2.6.9 at least, clear_page() is only ever called by clear_user_page(), which in turn is only ever called by drivers/media/video/video-buf.c.  I'm not using that driver, which explains why the instruction didn't show up when I disassembled the kernel.

Still, ppc32 also uses it in cacheable_memzero and __copy_tofrom_user. It's also used in cacheable_memcpy, but that routine doesn't seem to be used anywhere.

Chris