Ensure that newly allocated pages, which are faulted in in FOLL_DURABLE mode comes from non-movalbe pageblocks, to workaround migration failures with Contiguous Memory Allocator.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com --- include/linux/highmem.h | 12 ++++++++++-- include/linux/mm.h | 2 ++ mm/memory.c | 24 ++++++++++++++++++------ 3 files changed, 30 insertions(+), 8 deletions(-)
diff --git a/include/linux/highmem.h b/include/linux/highmem.h index 7fb31da..cf0b9d8 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -168,7 +168,8 @@ __alloc_zeroed_user_highpage(gfp_t movableflags, #endif
/** - * alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for a VMA that the caller knows can move + * alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for + * a VMA that the caller knows can move * @vma: The VMA the page is to be allocated for * @vaddr: The virtual address the page will be inserted into * @@ -177,11 +178,18 @@ __alloc_zeroed_user_highpage(gfp_t movableflags, */ static inline struct page * alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma, - unsigned long vaddr) + unsigned long vaddr) { return __alloc_zeroed_user_highpage(__GFP_MOVABLE, vma, vaddr); }
+static inline struct page * +alloc_zeroed_user_highpage(gfp_t gfp, struct vm_area_struct *vma, + unsigned long vaddr) +{ + return __alloc_zeroed_user_highpage(gfp, vma, vaddr); +} + static inline void clear_highpage(struct page *page) { void *kaddr = kmap_atomic(page); diff --git a/include/linux/mm.h b/include/linux/mm.h index 9806e54..c11f58f 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -165,6 +165,7 @@ extern pgprot_t protection_map[16]; #define FAULT_FLAG_RETRY_NOWAIT 0x10 /* Don't drop mmap_sem and wait when retrying */ #define FAULT_FLAG_KILLABLE 0x20 /* The fault task is in SIGKILL killable region */ #define FAULT_FLAG_TRIED 0x40 /* second try */ +#define FAULT_FLAG_NO_CMA 0x80 /* don't use CMA pages */
/* * vm_fault is filled by the the pagefault handler and passed to the vma's @@ -1633,6 +1634,7 @@ static inline struct page *follow_page(struct vm_area_struct *vma, #define FOLL_HWPOISON 0x100 /* check page is hwpoisoned */ #define FOLL_NUMA 0x200 /* force NUMA hinting page fault */ #define FOLL_MIGRATION 0x400 /* wait for page to replace migration entry */ +#define FOLL_DURABLE 0x800 /* get the page reference for a long time */
typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr, void *data); diff --git a/mm/memory.c b/mm/memory.c index 42dfd8e..2b9c2dd 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1816,6 +1816,9 @@ long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, int ret; unsigned int fault_flags = 0;
+ if (gup_flags & FOLL_DURABLE) + fault_flags = FAULT_FLAG_NO_CMA; + /* For mlock, just skip the stack guard page. */ if (foll_flags & FOLL_MLOCK) { if (stack_guard_page(vma, start)) @@ -2495,7 +2498,7 @@ static inline void cow_user_page(struct page *dst, struct page *src, unsigned lo */ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, pte_t *page_table, pmd_t *pmd, - spinlock_t *ptl, pte_t orig_pte) + spinlock_t *ptl, pte_t orig_pte, unsigned int flags) __releases(ptl) { struct page *old_page, *new_page = NULL; @@ -2505,6 +2508,10 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, struct page *dirty_page = NULL; unsigned long mmun_start = 0; /* For mmu_notifiers */ unsigned long mmun_end = 0; /* For mmu_notifiers */ + gfp_t gfp = GFP_HIGHUSER_MOVABLE; + + if (IS_ENABLED(CONFIG_CMA) && (flags & FAULT_FLAG_NO_CMA)) + gfp &= ~__GFP_MOVABLE;
old_page = vm_normal_page(vma, address, orig_pte); if (!old_page) { @@ -2668,11 +2675,11 @@ gotten: goto oom;
if (is_zero_pfn(pte_pfn(orig_pte))) { - new_page = alloc_zeroed_user_highpage_movable(vma, address); + new_page = alloc_zeroed_user_highpage(gfp, vma, address); if (!new_page) goto oom; } else { - new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address); + new_page = alloc_page_vma(gfp, vma, address); if (!new_page) goto oom; cow_user_page(new_page, old_page, address, vma); @@ -3032,7 +3039,7 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma, }
if (flags & FAULT_FLAG_WRITE) { - ret |= do_wp_page(mm, vma, address, page_table, pmd, ptl, pte); + ret |= do_wp_page(mm, vma, address, page_table, pmd, ptl, pte, flags); if (ret & VM_FAULT_ERROR) ret &= VM_FAULT_ERROR; goto out; @@ -3187,6 +3194,11 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma, struct vm_fault vmf; int ret; int page_mkwrite = 0; + gfp_t gfp = GFP_HIGHUSER_MOVABLE; + + if (IS_ENABLED(CONFIG_CMA) && (flags & FAULT_FLAG_NO_CMA)) + gfp &= ~__GFP_MOVABLE; +
/* * If we do COW later, allocate page befor taking lock_page() @@ -3197,7 +3209,7 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma, if (unlikely(anon_vma_prepare(vma))) return VM_FAULT_OOM;
- cow_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address); + cow_page = alloc_page_vma(gfp, vma, address); if (!cow_page) return VM_FAULT_OOM;
@@ -3614,7 +3626,7 @@ int handle_pte_fault(struct mm_struct *mm, if (flags & FAULT_FLAG_WRITE) { if (!pte_write(entry)) return do_wp_page(mm, vma, address, - pte, pmd, ptl, entry); + pte, pmd, ptl, entry, flags); entry = pte_mkdirty(entry); } entry = pte_mkyoung(entry);