On 17.03.21 15:31, Michal Hocko wrote:

On Wed 17-03-21 12:12:51, Oscar Salvador wrote:

quoted

pfn_range_valid_contig() bails out when it finds an in-use page or a
hugetlb page, among other things.
We can drop the in-use page check since __alloc_contig_pages can migrate
away those pages, and the hugetlb page check can go too since
isolate_migratepages_range is now capable of dealing with hugetlb pages.
Either way, those checks are racy so let the end function handle it
when the time comes.

I haven't realized PageHuge check is done this early. This means that
previous patches are not actually active until now which is not really
greate for bisectability. Can we remove the HugePage check earlier?

alloc_contig_pages() vs. alloc_contig_range(). The patches are active 
for virtio-mem and CMA AFAIKS.

-- 
Thanks,

David / dhildenb