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 | 6 +++--- mm/memory-failure.c | 2 +- mm/memory_hotplug.c | 2 +- mm/mempolicy.c | 2 +- mm/migrate.c | 7 ++++--- 7 files changed, 14 insertions(+), 13 deletions(-)
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index a18fc8e5a3ddb..c0ba379574a46 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -145,7 +145,7 @@ int 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); void putback_active_hugepage(struct page *page); void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason); void free_huge_page(struct page *page); @@ -326,9 +326,9 @@ 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 void putback_active_hugepage(struct page *page) diff --git a/mm/gup.c b/mm/gup.c index 6d5e4fd55d320..11307a8b20d58 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -1627,7 +1627,7 @@ static long check_and_migrate_cma_pages(struct mm_struct *mm, */ if (is_migrate_cma_page(head)) { if (PageHuge(head)) { - if (!isolate_huge_page(head, &cma_page_list)) + if (isolate_hugetlb(head, &cma_page_list)) isolation_error_count++; } else { if (!PageLRU(head) && drain_allow) { diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 3499b3803384b..81949f6d29af5 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5655,14 +5655,14 @@ 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(&hugetlb_lock); if (!PageHeadHuge(page) || !page_huge_active(page) || !get_page_unless_zero(page)) { - ret = false; + ret = -EBUSY; goto unlock; } clear_page_huge_active(page); diff --git a/mm/memory-failure.c b/mm/memory-failure.c index aef267c6a7246..b21dd4a793926 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1763,7 +1763,7 @@ 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 6275b1c05f111..f0633f9a91166 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1288,7 +1288,7 @@ 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 f9f47449e8dda..59d72b121346f 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -623,7 +623,7 @@ 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 b716b8fa2c3ff..fcb7eb6a6ecae 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -164,7 +164,7 @@ 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) { @@ -1657,8 +1657,9 @@ 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;