On 2022/8/24 16:10, David Hildenbrand wrote:
> On 19.08.22 11:30, Wupeng Ma wrote:
>> From: Ma Wupeng <mawupeng1@xxxxxxxxxx>
>>
>> Since min_free_kbytes is based on gfp_zone(GFP_USER) which does not include
>> zone movable. However zone movable will get its min share in
>> __setup_per_zone_wmarks() which does not make any sense.
>>
>> And like highmem pages, __GFP_HIGH and PF_MEMALLOC allocations usually
>> don't need movable pages, so there is no need to assign min pages for zone
>> movable.
>>
>> Let's cap pages_min for zone movable to a small value here just link
>> highmem pages.
>>
>> Signed-off-by: Ma Wupeng <mawupeng1@xxxxxxxxxx>
>> ---
>> mm/page_alloc.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
>> index e5486d47406e..ff644205370f 100644
>> --- a/mm/page_alloc.c
>> +++ b/mm/page_alloc.c
>> @@ -8638,7 +8638,7 @@ static void __setup_per_zone_wmarks(void)
>>
>> /* Calculate total number of !ZONE_HIGHMEM pages */
>> for_each_zone(zone) {
>> - if (!is_highmem(zone))
>> + if (!is_highmem(zone) && zone_idx(zone) != ZONE_MOVABLE)
>> lowmem_pages += zone_managed_pages(zone);
>> }
>>
>> @@ -8648,7 +8648,7 @@ static void __setup_per_zone_wmarks(void)
>> spin_lock_irqsave(&zone->lock, flags);
>> tmp = (u64)pages_min * zone_managed_pages(zone);
>> do_div(tmp, lowmem_pages);
>> - if (is_highmem(zone)) {
>> + if (is_highmem(zone) || zone_idx(zone) == ZONE_MOVABLE) {
>> /*
>> * __GFP_HIGH and PF_MEMALLOC allocations usually don't
>> * need highmem pages, so cap pages_min to a small
>
> This kind-off makes sense to me, but I'm not completely sure about all
> implications. We most certainly should update the comment as well.
Yes, we should certainly do this.
Thanks for reviewing.
>
