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

[Christoph Lameter]

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.