On Wed, Jan 20, 2021 at 9:33 AM Mike Kravetz <mike.krav...@oracle.com> wrote: > > Use the new hugetlb page specific flag HPageMigratable to replace the > page_huge_active interfaces. By it's name, page_huge_active implied > that a huge page was on the active list. However, that is not really > what code checking the flag wanted to know. It really wanted to determine > if the huge page could be migrated. This happens when the page is actually > added the page cache and/or task page table. This is the reasoning behind > the name change. > > The VM_BUG_ON_PAGE() calls in the *_huge_active() interfaces are not > really necessary as we KNOW the page is a hugetlb page. Therefore, they > are removed. > > The routine page_huge_active checked for PageHeadHuge before testing the > active bit. This is unnecessary in the case where we hold a reference or > lock and know it is a hugetlb head page. page_huge_active is also called > without holding a reference or lock (scan_movable_pages), and can race with > code freeing the page. The extra check in page_huge_active shortened the > race window, but did not prevent the race. Offline code calling > scan_movable_pages already deals with these races, so removing the check > is acceptable. Add comment to racy code. > > Signed-off-by: Mike Kravetz <mike.krav...@oracle.com>
Hi Mike, I found that you may forget to remove set_page_huge_active() from include/linux/hugetlb.h. diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 37fd248ce271..6f680cf0eee6 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -852,7 +852,7 @@ static inline void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, } #endif -void set_page_huge_active(struct page *page); + Thanks.
