Re: page fault scalability patch V12 [0/7]: Overview and performance

Nick Piggin
2004-12-10T04:54:41Z

Nick Piggin wrote:

> Yep, the update_mmu_cache issue is real. There is a parallel problem
> that is update_mmu_cache can be called on a pte who's page has since
> been evicted and reused. Again, that looks safe on IA64, but maybe
> not on other architectures.
>
> It can be solved by moving lru_cache_add to after update_mmu_cache in
> all cases but the "update accessed bit" type fault. I solved that by
> simply defining that out for architectures that don't need it - a raced
> fault will simply get repeated if need be.
>

The page-freed-before-update_mmu_cache issue can be solved in that way,
not the set_pte and update_mmu_cache not performed under the same ptl
section issue that you raised.