On Thu 15-11-18 07:50:40, Wei Yang wrote:
[...]
> @@ -1193,8 +1196,8 @@ static unsigned int count_free_highmem_pages(void)
> struct zone *zone;
> unsigned int cnt = 0;
>
> - for_each_populated_zone(zone)
> - if (is_highmem(zone))
> + for_each_zone(zone)
> + if (populated_zone(zone) && is_highmem(zone))
> cnt += zone_page_state(zone, NR_FREE_PAGES);
this should be for_each_managed_zone because we only care about highmem
zones which have pages in the allocator (NR_FREE_PAGES).
>
> return cnt;
> @@ -1239,10 +1242,10 @@ static unsigned int count_highmem_pages(void)
> struct zone *zone;
> unsigned int n = 0;
>
> - for_each_populated_zone(zone) {
> + for_each_zone(zone) {
> unsigned long pfn, max_zone_pfn;
>
> - if (!is_highmem(zone))
> + if (!populated_zone(zone) || !is_highmem(zone))
> continue;
>
> mark_free_pages(zone);
I am not familiar with this code much but I strongly suspect that we do
want for_each_managed_zone here because saveable_highmem_page skips over
all reserved pages which rules out the bootmem. But this should be
double checked with Rafael (Cc-ed).
Rafael, does this loop care about pages which are not managed by the
page allocator?
> @@ -1305,8 +1308,8 @@ static unsigned int count_data_pages(void)
> unsigned long pfn, max_zone_pfn;
> unsigned int n = 0;
>
> - for_each_populated_zone(zone) {
> - if (is_highmem(zone))
> + for_each_zone(zone) {
> + if (!populated_zone(zone) || is_highmem(zone))
> continue;
>
> mark_free_pages(zone);
> @@ -1399,9 +1402,12 @@ static void copy_data_pages(struct memory_bitmap
> *copy_bm,
> struct zone *zone;
> unsigned long pfn;
>
> - for_each_populated_zone(zone) {
> + for_each_zone(zone) {
> unsigned long max_zone_pfn;
>
> + if (!populated_zone(zone))
> + continue;
> +
> mark_free_pages(zone);
> max_zone_pfn = zone_end_pfn(zone);
> for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
> @@ -1717,7 +1723,10 @@ int hibernate_preallocate_memory(void)
> saveable += save_highmem;
> highmem = save_highmem;
> size = 0;
> - for_each_populated_zone(zone) {
> + for_each_zone(zone) {
> + if (!populated_zone(zone))
> + continue;
> +
> size += snapshot_additional_pages(zone);
> if (is_highmem(zone))
> highmem += zone_page_state(zone, NR_FREE_PAGES);
ditto for the above.
> @@ -1863,8 +1872,8 @@ static int enough_free_mem(unsigned int nr_pages,
> unsigned int nr_highmem)
> struct zone *zone;
> unsigned int free = alloc_normal;
>
> - for_each_populated_zone(zone)
> - if (!is_highmem(zone))
> + for_each_zone(zone)
> + if (populated_zone(zone) && !is_highmem(zone))
> free += zone_page_state(zone, NR_FREE_PAGES);
>
> nr_pages += count_pages_for_highmem(nr_highmem);
This one should be for_each_managed_zone (NR_FREE_PAGES)
The rest looks good to me.
--
Michal Hocko
SUSE Labs
