2013/03/05 15:57, Marek Szyprowski wrote: > 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.
In your idea, all users who uses non-movable pageblocks need to set gup_flags. It's not good. So how about prepare "get_user_pages_non_movable"? The idea is based on following Lin Feng's idea: https://lkml.org/lkml/2013/2/21/123 int get_user_pages_non_movable() { int flags = FOLL_TOUCH | FOLL_DURABLE; if (pages) flags |= FOLL_GET; if (write) flags |= FOLL_WRITE; if (force) flags |= FOLL_FORCE; return __get_user_pages(); } > > Signed-off-by: Marek Szyprowski <[email protected]> > Signed-off-by: Kyungmin Park <[email protected]> > --- > 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 */ How about FAULT_FLAG_NO_MIGLATABLE? I want to use it to not only CMA but also memory hotplug. > > /* > * 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; Pleae remove IS_ENABLED(CONFIG_CMA) check. > > 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; Pleae remove IS_ENABLED(CONFIG_CMA) check. > + > > /* > * 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); > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
