Re: PTE aging, ptep_test_and_clear_young() and TLB

[William Lee Irwin III <wli@holomorphy.com>]

On Sat, Apr 17, 2004 at 01:43:02PM -0700, William Lee Irwin III wrote:
>> The address and mm should already be recoverable via the pte page
>> tagging technique. The vma is recoverable from that, albeit at some
>> cost (mm->page_table_lock acquisition + find_vma() call). OTOH unless
>> kswapd's going wild it should largely count as a slow path anyway.

On Sun, Apr 18, 2004 at 10:36:16AM +0100, Russell King wrote:
> Actually, we don't actually need the VMA - if you look at flush_tlb_page()
> in include/asm-arm/tlbflush.h, we only really need the MM.  Therefore,
> it's pointless digging up the VMA.  (I did think that we didn't flush
> the I-TLB if VM_EXEC wasn't set, but I think that was a previous
> incarnation.)

This sounds like when hugh's stuff to prep for either his or andrea's
try_to_unmap() reimplementation goes in, something akin to current ppc64
may be needed for ARM. That should preserve the mm/address tagging by
shoving the pte page tagging into arch code.


-- wli
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