dcbz not used on ppc64?
cfriesen at nortelnetworks.com
Tue Jan 4 10:34:58 EST 2005
Anton Blanchard wrote:
>>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
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