On Thu 17-08-17 12:04:34, Chen Yu wrote:
[...]
> #ifdef CONFIG_HIBERNATION
>
> +/* Touch watchdog for every WD_INTERVAL_PAGE pages. */
> +#define WD_INTERVAL_PAGE 1000
traversing 1000 pages should never take too much time so this could be
overly aggressive. 100k pages could be acceptable as well. But I haven't
measure that so I might be easily wrong here. So this is just my 2c
> +
> void mark_free_pages(struct zone *zone)
> {
> unsigned long pfn, max_zone_pfn;
> unsigned long flags;
> - unsigned int order, t;
> + unsigned int order, t, page_num = 0;
> struct page *page;
>
> if (zone_is_empty(zone))
> @@ -2548,6 +2552,9 @@ void mark_free_pages(struct zone *zone)
> if (pfn_valid(pfn)) {
> page = pfn_to_page(pfn);
>
> + if (!((page_num++) % WD_INTERVAL_PAGE))
> + touch_nmi_watchdog();
> +
> if (page_zone(page) != zone)
> continue;
>
> @@ -2555,14 +2562,19 @@ void mark_free_pages(struct zone *zone)
> swsusp_unset_page_free(page);
> }
>
> + page_num = 0;
> +
this part doesn't make much sense to me. You are still inside the same
IRQ disabled section. So why would you want to start counting from 0
again. Not that this would make any difference in real life but the code
is not logical
> for_each_migratetype_order(order, t) {
> list_for_each_entry(page,
> &zone->free_area[order].free_list[t], lru) {
> unsigned long i;
>
> pfn = page_to_pfn(page);
> - for (i = 0; i < (1UL << order); i++)
> + for (i = 0; i < (1UL << order); i++) {
> + if (!((page_num++) % WD_INTERVAL_PAGE))
> + touch_nmi_watchdog();
> swsusp_set_page_free(pfn_to_page(pfn + i));
> + }
> }
> }
> spin_unlock_irqrestore(&zone->lock, flags);
> --
> 2.7.4
--
Michal Hocko
SUSE Labs
