[ofa-general] Re: [PATCH 2 of 8] Moves all mmu notifier methods outside the PT lock (first and not last

Christoph Lameter
2008-04-02T22:03:12Z

On Wed, 2 Apr 2008, Andrea Arcangeli wrote:

> diff --git a/mm/memory.c b/mm/memory.c
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -1626,9 +1626,10 @@
> */
> page_table = pte_offset_map_lock(mm, pmd, address,
> &ptl);
> - page_cache_release(old_page);
> + new_page = NULL;
> if (!pte_same(*page_table, orig_pte))
> goto unlock;
> + page_cache_release(old_page);
>
> page_mkwrite = 1;
> }

This is deferring frees and not moving the callouts. KVM specific? What
exactly is this doing?

A significant portion of this seems to be undoing what the first patch
did.