| Message ID | 20230821115624.158759-8-wangkefeng.wang@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm: migrate: more folio conversion and unify | expand |
On 21 Aug 2023, at 7:56, Kefeng Wang wrote: > There is some different between hugeTLB and THP behave when passed the > address of a tail page, for THP, it will migrate the entire THP page, > but for HugeTLB, it will return -EACCES, or -ENOENT before commit > e66f17ff7177 ("mm/hugetlb: take page table lock in follow_huge_pmd()"), > > -EACCES The page is mapped by multiple processes and can be moved > only if MPOL_MF_MOVE_ALL is specified. > -ENOENT The page is not present. > > But when check manual[1], both of the two errnos are not suitable, it > is better to keep the same behave between hugetlb and THP when passed > the address of a tail page, so let's just remove the PageHead() check > for HugeTLB. > > [1] https://man7.org/linux/man-pages/man2/move_pages.2.html > > Suggested-by: Mike Kravetz <mike.kravetz@oracle.com> > Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> > --- > mm/migrate.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > Acked-by: Zi Yan <ziy@nvidia.com> -- Best Regards, Yan, Zi
diff --git a/mm/migrate.c b/mm/migrate.c index 73572d5a5cd4..e8c3fb8974f9 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -2093,10 +2093,8 @@ static int add_page_for_migration(struct mm_struct *mm, const void __user *p, goto out_putfolio; if (folio_test_hugetlb(folio)) { - if (PageHead(page)) { - isolated = isolate_hugetlb(folio, pagelist); - err = isolated ? 1 : -EBUSY; - } + isolated = isolate_hugetlb(folio, pagelist); + err = isolated ? 1 : -EBUSY; } else { isolated = folio_isolate_lru(folio); if (!isolated) {
There is some different between hugeTLB and THP behave when passed the address of a tail page, for THP, it will migrate the entire THP page, but for HugeTLB, it will return -EACCES, or -ENOENT before commit e66f17ff7177 ("mm/hugetlb: take page table lock in follow_huge_pmd()"), -EACCES The page is mapped by multiple processes and can be moved only if MPOL_MF_MOVE_ALL is specified. -ENOENT The page is not present. But when check manual[1], both of the two errnos are not suitable, it is better to keep the same behave between hugetlb and THP when passed the address of a tail page, so let's just remove the PageHead() check for HugeTLB. [1] https://man7.org/linux/man-pages/man2/move_pages.2.html Suggested-by: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> --- mm/migrate.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)