At some point in the past, I wrote:
>> My i386 version, which makes ->virtual conditional on CONFIG_HIGHMEM as
>> well, is at:
On Mon, Jan 07, 2002 at 12:33:26AM +1100, Anton Blanchard wrote:
> Id like to do redo some profiling, on ppc64 we had page_address() doing
> pointer arithmetic (instead of page->virtual) and the compiler created
> an awful sequence of instructions in the acenic interrupt handler.
> A zero copy TCP benchmark made it rather obvious.
I'm not entirely surprised at this, CONFIG_HIGHMEM is probably just
not quite a strict enough criterion for eliminating ->virtual as it's
a time/space tradeoff that just happens to be bad on ppc64. Maybe we
should figure out some other criterion in addition to it.
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