Mostly LGTM. I recall that in some corner cases the migratetype stored
for a pcppage does not correspond to the pagetype of the pfnblock ... I
do wonder if that can trick us here in doing some accounting wrong., no
that we account free pages per mirgatetype.
> /*
> * Set the pageblock if the isolated page is at least half of a
> @@ -6038,14 +6038,16 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)
> struct free_area *area = &zone->free_area[order];
> int type;
>
> - nr[order] = area->nr_free;
> - total += nr[order] << order;
> + nr[order] = 0;
> + types[order] = 0;
Why the indentation change? Looks unrelated to me.
>
> - types[order] = 0;
> for (type = 0; type < MIGRATE_TYPES; type++) {
> if (!free_area_empty(area, type))
> types[order] |= 1 << type;
> + nr[order] += area->nr_free[type];
> }
> +
> + total += nr[order] << order;
> }
> spin_unlock_irqrestore(&zone->lock, flags);
> for (order = 0; order < MAX_ORDER; order++) {
> @@ -6623,7 +6625,7 @@ static void __meminit zone_init_free_lists(struct zone *zone)
> unsigned int order, t;
> for_each_migratetype_order(order, t) {
> INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
> - zone->free_area[order].nr_free = 0;
> + zone->free_area[order].nr_free[t] = 0;
> }
> }
>
> @@ -9317,6 +9319,7 @@ void __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
> struct page *page;
> struct zone *zone;
> unsigned int order;
> + unsigned int migratetype;
> unsigned long flags;
>
> offline_mem_sections(pfn, end_pfn);
> @@ -9346,7 +9349,8 @@ void __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
> BUG_ON(page_count(page));
> BUG_ON(!PageBuddy(page));
> order = buddy_order(page);
> - del_page_from_free_list(page, zone, order);
> + migratetype = get_pfnblock_migratetype(page, pfn);
As the free pages are isolated, theoretically this should be
MIGRATE_ISOLATE.
> + del_page_from_free_list(page, zone, order, migratetype);
> pfn += (1 << order);
> }
> spin_unlock_irqrestore(&zone->lock, flags);
> @@ -9428,7 +9432,7 @@ bool take_page_off_buddy(struct page *page)
> int migratetype = get_pfnblock_migratetype(page_head,
> pfn_head);
>
> - del_page_from_free_list(page_head, zone, page_order);
> + del_page_from_free_list(page_head, zone, page_order, migratetype);
> break_down_buddy_pages(zone, page_head, page, 0,
> page_order, migratetype);
> if (!is_migrate_isolate(migratetype))
> diff --git a/mm/page_reporting.c b/mm/page_reporting.c
> index 382958eef8..4e45ae95db 100644
> --- a/mm/page_reporting.c
> +++ b/mm/page_reporting.c
> @@ -145,7 +145,7 @@ page_reporting_cycle(struct page_reporting_dev_info *prdev, struct zone *zone,
> * The division here should be cheap since PAGE_REPORTING_CAPACITY
> * should always be a power of 2.
> */
> - budget = DIV_ROUND_UP(area->nr_free, PAGE_REPORTING_CAPACITY * 16);
> + budget = DIV_ROUND_UP(area->nr_free[mt], PAGE_REPORTING_CAPACITY * 16);
>
I think we might want the total free pages here. If we want to change
the behavior, we should do it in a separate patch.
--
Thanks,
David / dhildenb
