On 2026/6/1 23:05, David Hildenbrand (Arm) wrote:
On 6/1/26 17:00, Nico Pache wrote:
On Mon, Jun 1, 2026 at 5:14 AM David Hildenbrand (Arm) <[email protected]> wrote:
On 6/1/26 12:47, Lance Yang wrote:
Ah, cool! __folio_mark_uptodate() already does the job :P
So yeah, no extra smp_wmb() needed here!
Yeah. BTW, I think we'd need a spin_lock_nested(), so @Nico, treat my code as a
draft.
Okay, I read the above and did some investigating.
I will try to implement and verify the changes you suggested :)
Or an even crazier idea... what if we ensure MIPS checks for PMD_none
before walking a PTE table?
But how would they update the cache then correctly?
I'm too non-MIPS to know the answer :)
Right, that's my concern as well ...
If MIPS sees pmd_none(), it has no PTE table to walk, so it also has
no way to do the cache update it wanted to do, I guess :)
But, the PTE table is not really gone there. khugepaged only cleared
the PMD temporarily while still using the old PTE table through _pmd.
So I'd go with David's suggestion:
"
Best to make sure the page table is already installed when updating
the entries.
"
Cheers, Lance
