From: Kefeng Wang wangkefeng.wang@huawei.com
mainline inclusion from mainline-v6.7-rc1 commit b426ed7889be80359cb4edef142e5c5fa697b068 category: other bugzilla: https://gitee.com/openeuler/kernel/issues/I8JQWQ
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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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
Link: https://lkml.kernel.org/r/20230913095131.2426871-8-wangkefeng.wang@huawei.co... Signed-off-by: Kefeng Wang wangkefeng.wang@huawei.com Suggested-by: Mike Kravetz mike.kravetz@oracle.com Acked-by: Zi Yan ziy@nvidia.com Cc: David Hildenbrand david@redhat.com Cc: "Huang, Ying" ying.huang@intel.com Cc: Hugh Dickins hughd@google.com Cc: Matthew Wilcox (Oracle) willy@infradead.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: ZhangPeng zhangpeng362@huawei.com --- mm/migrate.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/mm/migrate.c b/mm/migrate.c index 85239bb95e24..f8d92193b98f 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -2096,10 +2096,8 @@ 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) {