From: Miaohe Lin linmiaohe@huawei.com
[ Upstream commit 7ce82f4c3f3ead13a9d9498768e3b1a79975c4d8 ]
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: e8db67eb0ded ("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 Stable-dep-of: 73bdf65ea748 ("migrate: hugetlb: check for hugetlb shared PMD in node migration") Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/hugetlb.h | 6 +++--- mm/gup.c | 2 +- mm/hugetlb.c | 11 +++++------ mm/memory-failure.c | 2 +- mm/memory_hotplug.c | 2 +- mm/mempolicy.c | 2 +- mm/migrate.c | 7 ++++--- 7 files changed, 16 insertions(+), 16 deletions(-)
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index cac25ad9d643f..f98d747f983b9 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -166,7 +166,7 @@ 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); @@ -354,9 +354,9 @@ 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) diff --git a/mm/gup.c b/mm/gup.c index 2370565a81dc3..0a1839b325747 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -1877,7 +1877,7 @@ static long check_and_migrate_movable_pages(unsigned long nr_pages, */ if (!is_pinnable_page(head)) { if (PageHuge(head)) { - if (!isolate_huge_page(head, &movable_page_list)) + if (isolate_hugetlb(head, &movable_page_list)) isolation_error_count++; } else { if (!PageLRU(head) && drain_allow) { diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 8599f16d4aa4f..2f5c1b2456ef2 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2656,8 +2656,7 @@ static int alloc_and_dissolve_huge_page(struct hstate *h, struct page *old_page, * 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)) { @@ -2733,7 +2732,7 @@ 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); @@ -6277,15 +6276,15 @@ 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); diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 2ad0f45800916..9f9dd968fbe3c 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -2106,7 +2106,7 @@ 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); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 9fd0be32a281e..81f2a97c886c9 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1704,7 +1704,7 @@ 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; diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 4472be6f123db..8687781b41c96 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -604,7 +604,7 @@ 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 diff --git a/mm/migrate.c b/mm/migrate.c index 7da052c6cf1ea..dd50b1cc089e0 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -134,7 +134,7 @@ 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) { @@ -1722,8 +1722,9 @@ 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;