mm/migration: return errno when isolate_huge_page failed

[ Upstream commit 7ce82f4c3f ]

We might fail to isolate huge page due to e.g.  the page is under
migration which cleared HPageMigratable.  We should return errno in this
case rather than always return 1 which could confuse the user, i.e.  the
caller might think all of the memory is migrated while the hugetlb page is
left behind.  We make the prototype of isolate_huge_page consistent with
isolate_lru_page as suggested by Huang Ying and rename isolate_huge_page
to isolate_hugetlb as suggested by Muchun to improve the readability.

Link: https://lkml.kernel.org/r/20220530113016.16663-4-linmiaohe@huawei.com
Fixes: e8db67eb0d ("mm: migrate: move_pages() supports thp migration")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Suggested-by: Huang Ying <ying.huang@intel.com>
Reported-by: kernel test robot <lkp@intel.com> (build error)
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Miaohe Lin 2022-05-30 19:30:15 +08:00 committed by Greg Kroah-Hartman
parent e53b162cd8
commit c36770e67e
7 changed files with 16 additions and 16 deletions

View File

@ -167,7 +167,7 @@ bool hugetlb_reserve_pages(struct inode *inode, long from, long to,
vm_flags_t vm_flags);
long hugetlb_unreserve_pages(struct inode *inode, long start, long end,
long freed);
bool isolate_huge_page(struct page *page, struct list_head *list);
int isolate_hugetlb(struct page *page, struct list_head *list);
int get_hwpoison_huge_page(struct page *page, bool *hugetlb);
int get_huge_page_for_hwpoison(unsigned long pfn, int flags);
void putback_active_hugepage(struct page *page);
@ -369,9 +369,9 @@ static inline pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr,
return NULL;
}
static inline bool isolate_huge_page(struct page *page, struct list_head *list)
static inline int isolate_hugetlb(struct page *page, struct list_head *list)
{
return false;
return -EBUSY;
}
static inline int get_hwpoison_huge_page(struct page *page, bool *hugetlb)

View File

@ -1795,7 +1795,7 @@ static long check_and_migrate_movable_pages(unsigned long nr_pages,
* Try to move out any movable page before pinning the range.
*/
if (folio_test_hugetlb(folio)) {
if (!isolate_huge_page(&folio->page,
if (isolate_hugetlb(&folio->page,
&movable_page_list))
isolation_error_count++;
continue;

View File

@ -2758,8 +2758,7 @@ retry:
* Fail with -EBUSY if not possible.
*/
spin_unlock_irq(&hugetlb_lock);
if (!isolate_huge_page(old_page, list))
ret = -EBUSY;
ret = isolate_hugetlb(old_page, list);
spin_lock_irq(&hugetlb_lock);
goto free_new;
} else if (!HPageFreed(old_page)) {
@ -2835,7 +2834,7 @@ int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list)
if (hstate_is_gigantic(h))
return -ENOMEM;
if (page_count(head) && isolate_huge_page(head, list))
if (page_count(head) && !isolate_hugetlb(head, list))
ret = 0;
else if (!page_count(head))
ret = alloc_and_dissolve_huge_page(h, head, list);
@ -6758,15 +6757,15 @@ follow_huge_pgd(struct mm_struct *mm, unsigned long address, pgd_t *pgd, int fla
return pte_page(*(pte_t *)pgd) + ((address & ~PGDIR_MASK) >> PAGE_SHIFT);
}
bool isolate_huge_page(struct page *page, struct list_head *list)
int isolate_hugetlb(struct page *page, struct list_head *list)
{
bool ret = true;
int ret = 0;
spin_lock_irq(&hugetlb_lock);
if (!PageHeadHuge(page) ||
!HPageMigratable(page) ||
!get_page_unless_zero(page)) {
ret = false;
ret = -EBUSY;
goto unlock;
}
ClearHPageMigratable(page);

View File

@ -2211,7 +2211,7 @@ static bool isolate_page(struct page *page, struct list_head *pagelist)
bool lru = PageLRU(page);
if (PageHuge(page)) {
isolated = isolate_huge_page(page, pagelist);
isolated = !isolate_hugetlb(page, pagelist);
} else {
if (lru)
isolated = !isolate_lru_page(page);

View File

@ -1627,7 +1627,7 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
if (PageHuge(page)) {
pfn = page_to_pfn(head) + compound_nr(head) - 1;
isolate_huge_page(head, &source);
isolate_hugetlb(head, &source);
continue;
} else if (PageTransHuge(page))
pfn = page_to_pfn(head) + thp_nr_pages(page) - 1;

View File

@ -607,7 +607,7 @@ static int queue_pages_hugetlb(pte_t *pte, unsigned long hmask,
/* With MPOL_MF_MOVE, we migrate only unshared hugepage. */
if (flags & (MPOL_MF_MOVE_ALL) ||
(flags & MPOL_MF_MOVE && page_mapcount(page) == 1)) {
if (!isolate_huge_page(page, qp->pagelist) &&
if (isolate_hugetlb(page, qp->pagelist) &&
(flags & MPOL_MF_STRICT))
/*
* Failed to isolate page but allow migrating pages

View File

@ -133,7 +133,7 @@ static void putback_movable_page(struct page *page)
*
* This function shall be used whenever the isolated pageset has been
* built from lru, balloon, hugetlbfs page. See isolate_migratepages_range()
* and isolate_huge_page().
* and isolate_hugetlb().
*/
void putback_movable_pages(struct list_head *l)
{
@ -1631,8 +1631,9 @@ static int add_page_for_migration(struct mm_struct *mm, unsigned long addr,
if (PageHuge(page)) {
if (PageHead(page)) {
isolate_huge_page(page, pagelist);
err = 1;
err = isolate_hugetlb(page, pagelist);
if (!err)
err = 1;
}
} else {
struct page *head;