On Fri, Nov 16, 2018 at 11:24:05AM +0100, Michal Hocko wrote:
>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?
>
Hi, Rafael
Your opinion on this change and the following one is appreciated :-)
>> @@ -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
--
Wei Yang
Help you, Help me
