Re: [PATCH][RFC] PM / Hibernate: Feed NMI wathdog when creating snapshot

[Michal Hocko]

On Tue 15-08-17 01:19:16, Chen Yu wrote:
[...]
> @@ -2561,8 +2562,10 @@ void mark_free_pages(struct zone *zone)
>  			unsigned long i;
>  
>  			pfn = page_to_pfn(page);
> -			for (i = 0; i < (1UL << order); i++)
> +			for (i = 0; i < (1UL << order); i++) {
>  				swsusp_set_page_free(pfn_to_page(pfn + i));
> +				touch_nmi_watchdog();
> +			}

this is rather excessive. Why don't you simply call touch_nmi_watchdog
once per every 1000 pages? Or once per free_list entry?

Moreover why don't you need to touch_nmi_watchdog in the loop over all
pfns in the zone (right above this loop)?
-- 
Michal Hocko
SUSE Labs