I've looked at the flush_cache_xxx() code in pgtable.h and it
has the following code.
/* Caches aren't brain-dead on the intel. */
#define flush_cache_all() do { } while (0)
#define flush_cache_mm(mm) do { } while (0)
#define flush_cache_range(mm, start, end) do { } while (0)
#define flush_cache_page(vma, vmaddr) do { } while (0)
I've tried disabling the caches from the BIOS setup, but the
performance of the system and the behavior is unchanged, so I
suspect the BIOS isn't really turning off the caches.
These routines in question are unnecessary on Intel machines, if this
were not the case MS-DOS wouldn't work on your machine.
Later,
David S. Miller
davem@caip.rutgers.edu