Re: [PATCH mm] swapless page migration: fix swapops.h:97 BUG

[Hugh Dickins <hugh@veritas.com>]

On Wed, 24 May 2006, Christoph Lameter wrote:
> 
> Thats is very subtle. I hope there are no other areas where the child vma 
> has to be processed before the parent vma?

I've considered, and very much doubt it; and if there are, they'd
have to be peculiar to anonymous, since they'd already have been
wrong for the vma_prio_tree cases.

> An alternative would be to 
> make remove_anon_migration_ptes walk the list in reverse and add a big 
> comment.

No, even without this migration issue, I'd much rather have anon_vmas
inserted in the new list_add_tail way, matching the prio_tree direction.
It's asking for trouble to have opposite conventions there (and much
less surprising to insert child after parent than before).

Hugh