Re: [2/7] Xen VMM patch set : return code for arch_free_page

[Andrea Arcangeli <andrea@suse.de>]

On Fri, Nov 19, 2004 at 11:20:54PM +0000, Ian Pratt wrote:
> 
> This patch adds a return value to the existing arch_free_page function
> that indicates whether the normal free routine still has work to
> do. The only architecture that currently uses arch_free_page is arch
> 'um'. arch xen needs this for 'foreign pages' - pages that don't
> belong to the page allocator but are instead managed by custom
> allocators. Such pages are marked using PG_arch_1.

This sure looks good too.

> @@ -508,7 +509,8 @@ static void fastcall free_hot_cold_page(
>  	struct per_cpu_pages *pcp;
>  	unsigned long flags;
>  
> -	arch_free_page(page, 0);
> +	if (arch_free_page(page, 0))
> +		return;

If you want you can microoptimize the guest placing zone =
page_zone(page) after arch_free_page. Just a side note (it cannot be
measurable anyways).