On 09.12.20 11:03, Muchun Song wrote: > On Wed, Dec 9, 2020 at 5:57 PM David Hildenbrand <david@xxxxxxxxxx> wrote: >> >> On 30.11.20 16:18, Muchun Song wrote: >>> We only can free the tail vmemmap pages of HugeTLB to the buddy allocator >>> when the size of struct page is a power of two. >>> >>> Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> >>> --- >>> mm/hugetlb_vmemmap.c | 5 +++++ >>> 1 file changed, 5 insertions(+) >>> >>> diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c >>> index 51152e258f39..ad8fc61ea273 100644 >>> --- a/mm/hugetlb_vmemmap.c >>> +++ b/mm/hugetlb_vmemmap.c >>> @@ -111,6 +111,11 @@ void __init hugetlb_vmemmap_init(struct hstate *h) >>> unsigned int nr_pages = pages_per_huge_page(h); >>> unsigned int vmemmap_pages; >>> >>> + if (!is_power_of_2(sizeof(struct page))) { >>> + pr_info("disable freeing vmemmap pages for %s\n", h->name); >> >> I'd just drop that pr_info(). Users are able to observe that it's >> working (below), so they are able to identify that it's not working as well. > > The below is just a pr_debug. Do you suggest converting it to pr_info? Good question. I wonder if users really have to know in most cases. Maybe pr_debug() is good enough in environments where we want to debug why stuff is not working as expected. -- Thanks, David / dhildenb