Re: [PATCH v14 08/14] mm: multi-gen LRU: support page table walks

Linus Torvalds
2022-10-20T17:36:02Z

On Thu, Oct 20, 2022 at 7:14 AM Peter Zijlstra <peterz@infradead.org> wrote:
>
> So I've been sitting on these here patches (and never having time to
> repost them), which is how I noticed in the first place:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git/log/?h=x86/mm.pae

Well, that seems an improvement. I don't love how GUP_GET_PTE_LOW_HIGH
now affects the PMD too, but if it's ok for all the three users, I
guess it's ok. Maybe rename it now that it's not just the PTE?

That said, I reacted to that cmpxchg loop:

} while (cmpxchg64(&pmdp->pmd, old.pmd, 0ULL) != old.pmd);

is this series just so old (but rebased) that it doesn't use "try_cmpxchg64()"?

Linus