From: Davidlohr Bueso <davidlohr@xxxxxx> While testing some changes, I noticed an issue triggered by the libhugetlbfs test-suite. This is caused by commit 309381fe (mm: dump page when hitting a VM_BUG_ON using VM_BUG_ON_PAGE), where an application can unexpectedly OOM due to another program that using, or reserving, pool_size-1 pages later triggers a VM_BUG_ON_PAGE and thus greedly leaves no memory to the rest of the hugetlb aware tasks. For example, in libhugetlbfs 2.14: mmap-gettest 10 32783 (2M: 64): <---- hit VM_BUG_ON_PAGE mmap-cow 32782 32783 (2M: 32): FAIL Failed to create shared mapping: Cannot allocate memory mmap-cow 32782 32783 (2M: 64): FAIL Failed to create shared mapping: Cannot allocate memory While I have not looked into why 'mmap-gettest' keeps failing, it is of no importance to this particular issue. This problem is similar to why we have the hugetlb_instantiation_mutex, hugepages are quite finite. Revert the use of VM_BUG_ON_PAGE back to just VM_BUG_ON. Signed-off-by: Davidlohr Bueso <davidlohr@xxxxxx> --- include/linux/hugetlb.h | 3 +-- include/linux/hugetlb_cgroup.h | 5 ++--- mm/hugetlb.c | 10 +++++----- mm/hugetlb_cgroup.c | 2 +- 4 files changed, 9 insertions(+), 11 deletions(-) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 8c43cc4..d01cc97 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -2,7 +2,6 @@ #define _LINUX_HUGETLB_H #include <linux/mm_types.h> -#include <linux/mmdebug.h> #include <linux/fs.h> #include <linux/hugetlb_inline.h> #include <linux/cgroup.h> @@ -355,7 +354,7 @@ static inline pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma, static inline struct hstate *page_hstate(struct page *page) { - VM_BUG_ON_PAGE(!PageHuge(page), page); + VM_BUG_ON(!PageHuge(page)); return size_to_hstate(PAGE_SIZE << compound_order(page)); } diff --git a/include/linux/hugetlb_cgroup.h b/include/linux/hugetlb_cgroup.h index 787bba3..ce8217f 100644 --- a/include/linux/hugetlb_cgroup.h +++ b/include/linux/hugetlb_cgroup.h @@ -15,7 +15,6 @@ #ifndef _LINUX_HUGETLB_CGROUP_H #define _LINUX_HUGETLB_CGROUP_H -#include <linux/mmdebug.h> #include <linux/res_counter.h> struct hugetlb_cgroup; @@ -29,7 +28,7 @@ struct hugetlb_cgroup; static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page) { - VM_BUG_ON_PAGE(!PageHuge(page), page); + VM_BUG_ON(!PageHuge(page)); if (compound_order(page) < HUGETLB_CGROUP_MIN_ORDER) return NULL; @@ -39,7 +38,7 @@ static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page) static inline int set_hugetlb_cgroup(struct page *page, struct hugetlb_cgroup *h_cg) { - VM_BUG_ON_PAGE(!PageHuge(page), page); + VM_BUG_ON(!PageHuge(page)); if (compound_order(page) < HUGETLB_CGROUP_MIN_ORDER) return -1; diff --git a/mm/hugetlb.c b/mm/hugetlb.c index c01cb9f..04306b9 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -584,7 +584,7 @@ static void update_and_free_page(struct hstate *h, struct page *page) 1 << PG_active | 1 << PG_reserved | 1 << PG_private | 1 << PG_writeback); } - VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page); + VM_BUG_ON(hugetlb_cgroup_from_page(page)); set_compound_page_dtor(page, NULL); set_page_refcounted(page); arch_release_hugepage(page); @@ -1089,7 +1089,7 @@ retry: * no users -- drop the buddy allocator's reference. */ put_page_testzero(page); - VM_BUG_ON_PAGE(page_count(page), page); + VM_BUG_ON(page_count(page)); enqueue_huge_page(h, page); } free: @@ -3503,7 +3503,7 @@ int dequeue_hwpoisoned_huge_page(struct page *hpage) bool isolate_huge_page(struct page *page, struct list_head *list) { - VM_BUG_ON_PAGE(!PageHead(page), page); + VM_BUG_ON(!PageHead(page)); if (!get_page_unless_zero(page)) return false; spin_lock(&hugetlb_lock); @@ -3514,7 +3514,7 @@ bool isolate_huge_page(struct page *page, struct list_head *list) void putback_active_hugepage(struct page *page) { - VM_BUG_ON_PAGE(!PageHead(page), page); + VM_BUG_ON(!PageHead(page)); spin_lock(&hugetlb_lock); list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist); spin_unlock(&hugetlb_lock); @@ -3523,7 +3523,7 @@ void putback_active_hugepage(struct page *page) bool is_hugepage_active(struct page *page) { - VM_BUG_ON_PAGE(!PageHuge(page), page); + VM_BUG_ON(!PageHuge(page)); /* * This function can be called for a tail page because the caller, * scan_movable_pages, scans through a given pfn-range which typically diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c index cb00829..d747a84 100644 --- a/mm/hugetlb_cgroup.c +++ b/mm/hugetlb_cgroup.c @@ -390,7 +390,7 @@ void hugetlb_cgroup_migrate(struct page *oldhpage, struct page *newhpage) if (hugetlb_cgroup_disabled()) return; - VM_BUG_ON_PAGE(!PageHuge(oldhpage), oldhpage); + VM_BUG_ON(!PageHuge(oldhpage)); spin_lock(&hugetlb_lock); h_cg = hugetlb_cgroup_from_page(oldhpage); set_hugetlb_cgroup(oldhpage, NULL); -- 1.8.1.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. 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