X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fmm%2Fhuge_memory.c;h=62fe06bb7d04bacccc8c2213a6a65134fa274010;hb=e09b41010ba33a20a87472ee821fa407a5b8da36;hp=078832cf3636579e1d9cc1c396b037319e52a6bd;hpb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;p=kvmfornfv.git diff --git a/kernel/mm/huge_memory.c b/kernel/mm/huge_memory.c index 078832cf3..62fe06bb7 100644 --- a/kernel/mm/huge_memory.c +++ b/kernel/mm/huge_memory.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include #include @@ -23,6 +24,8 @@ #include #include #include +#include +#include #include #include @@ -104,7 +107,7 @@ static struct khugepaged_scan khugepaged_scan = { }; -static int set_recommended_min_free_kbytes(void) +static void set_recommended_min_free_kbytes(void) { struct zone *zone; int nr_zones = 0; @@ -113,7 +116,7 @@ static int set_recommended_min_free_kbytes(void) for_each_populated_zone(zone) nr_zones++; - /* Make sure at least 2 hugepages are free for MIGRATE_RESERVE */ + /* Ensure 2 pageblocks are free to assist fragmentation avoidance */ recommended_min = pageblock_nr_pages * nr_zones * 2; /* @@ -139,7 +142,6 @@ static int set_recommended_min_free_kbytes(void) min_free_kbytes = recommended_min; } setup_per_zone_wmarks(); - return 0; } static int start_stop_khugepaged(void) @@ -149,7 +151,7 @@ static int start_stop_khugepaged(void) if (!khugepaged_thread) khugepaged_thread = kthread_run(khugepaged, NULL, "khugepaged"); - if (unlikely(IS_ERR(khugepaged_thread))) { + if (IS_ERR(khugepaged_thread)) { pr_err("khugepaged: kthread_run(khugepaged) failed\n"); err = PTR_ERR(khugepaged_thread); khugepaged_thread = NULL; @@ -171,12 +173,7 @@ fail: static atomic_t huge_zero_refcount; struct page *huge_zero_page __read_mostly; -static inline bool is_huge_zero_pmd(pmd_t pmd) -{ - return is_huge_zero_page(pmd_page(pmd)); -} - -static struct page *get_huge_zero_page(void) +struct page *get_huge_zero_page(void) { struct page *zero_page; retry: @@ -716,21 +713,27 @@ static inline pmd_t mk_huge_pmd(struct page *page, pgprot_t prot) static int __do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, - unsigned long haddr, pmd_t *pmd, - struct page *page, gfp_t gfp) + unsigned long address, pmd_t *pmd, + struct page *page, gfp_t gfp, + unsigned int flags) { struct mem_cgroup *memcg; pgtable_t pgtable; spinlock_t *ptl; + unsigned long haddr = address & HPAGE_PMD_MASK; VM_BUG_ON_PAGE(!PageCompound(page), page); - if (mem_cgroup_try_charge(page, mm, gfp, &memcg)) - return VM_FAULT_OOM; + if (mem_cgroup_try_charge(page, mm, gfp, &memcg)) { + put_page(page); + count_vm_event(THP_FAULT_FALLBACK); + return VM_FAULT_FALLBACK; + } pgtable = pte_alloc_one(mm, haddr); if (unlikely(!pgtable)) { mem_cgroup_cancel_charge(page, memcg); + put_page(page); return VM_FAULT_OOM; } @@ -750,6 +753,21 @@ static int __do_huge_pmd_anonymous_page(struct mm_struct *mm, pte_free(mm, pgtable); } else { pmd_t entry; + + /* Deliver the page fault to userland */ + if (userfaultfd_missing(vma)) { + int ret; + + spin_unlock(ptl); + mem_cgroup_cancel_charge(page, memcg); + put_page(page); + pte_free(mm, pgtable); + ret = handle_userfault(vma, address, flags, + VM_UFFD_MISSING); + VM_BUG_ON(ret & VM_FAULT_FALLBACK); + return ret; + } + entry = mk_huge_pmd(page, vma->vm_page_prot); entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); page_add_new_anon_rmap(page, vma, haddr); @@ -760,6 +778,7 @@ static int __do_huge_pmd_anonymous_page(struct mm_struct *mm, add_mm_counter(mm, MM_ANONPAGES, HPAGE_PMD_NR); atomic_long_inc(&mm->nr_ptes); spin_unlock(ptl); + count_vm_event(THP_FAULT_ALLOC); } return 0; @@ -767,7 +786,7 @@ static int __do_huge_pmd_anonymous_page(struct mm_struct *mm, static inline gfp_t alloc_hugepage_gfpmask(int defrag, gfp_t extra_gfp) { - return (GFP_TRANSHUGE & ~(defrag ? 0 : __GFP_WAIT)) | extra_gfp; + return (GFP_TRANSHUGE & ~(defrag ? 0 : __GFP_RECLAIM)) | extra_gfp; } /* Caller must hold page table lock. */ @@ -806,6 +825,7 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, pgtable_t pgtable; struct page *zero_page; bool set; + int ret; pgtable = pte_alloc_one(mm, haddr); if (unlikely(!pgtable)) return VM_FAULT_OOM; @@ -816,14 +836,28 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, return VM_FAULT_FALLBACK; } ptl = pmd_lock(mm, pmd); - set = set_huge_zero_page(pgtable, mm, vma, haddr, pmd, - zero_page); - spin_unlock(ptl); + ret = 0; + set = false; + if (pmd_none(*pmd)) { + if (userfaultfd_missing(vma)) { + spin_unlock(ptl); + ret = handle_userfault(vma, address, flags, + VM_UFFD_MISSING); + VM_BUG_ON(ret & VM_FAULT_FALLBACK); + } else { + set_huge_zero_page(pgtable, mm, vma, + haddr, pmd, + zero_page); + spin_unlock(ptl); + set = true; + } + } else + spin_unlock(ptl); if (!set) { pte_free(mm, pgtable); put_huge_zero_page(); } - return 0; + return ret; } gfp = alloc_hugepage_gfpmask(transparent_hugepage_defrag(vma), 0); page = alloc_hugepage_vma(gfp, vma, haddr, HPAGE_PMD_ORDER); @@ -831,14 +865,51 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, count_vm_event(THP_FAULT_FALLBACK); return VM_FAULT_FALLBACK; } - if (unlikely(__do_huge_pmd_anonymous_page(mm, vma, haddr, pmd, page, gfp))) { - put_page(page); - count_vm_event(THP_FAULT_FALLBACK); - return VM_FAULT_FALLBACK; + return __do_huge_pmd_anonymous_page(mm, vma, address, pmd, page, gfp, + flags); +} + +static void insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, + pmd_t *pmd, unsigned long pfn, pgprot_t prot, bool write) +{ + struct mm_struct *mm = vma->vm_mm; + pmd_t entry; + spinlock_t *ptl; + + ptl = pmd_lock(mm, pmd); + if (pmd_none(*pmd)) { + entry = pmd_mkhuge(pfn_pmd(pfn, prot)); + if (write) { + entry = pmd_mkyoung(pmd_mkdirty(entry)); + entry = maybe_pmd_mkwrite(entry, vma); + } + set_pmd_at(mm, addr, pmd, entry); + update_mmu_cache_pmd(vma, addr, pmd); } + spin_unlock(ptl); +} - count_vm_event(THP_FAULT_ALLOC); - return 0; +int vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, + pmd_t *pmd, unsigned long pfn, bool write) +{ + pgprot_t pgprot = vma->vm_page_prot; + /* + * If we had pmd_special, we could avoid all these restrictions, + * but we need to be consistent with PTEs and architectures that + * can't support a 'special' bit. + */ + BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))); + BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) == + (VM_PFNMAP|VM_MIXEDMAP)); + BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags)); + BUG_ON((vma->vm_flags & VM_MIXEDMAP) && pfn_valid(pfn)); + + if (addr < vma->vm_start || addr >= vma->vm_end) + return VM_FAULT_SIGBUS; + if (track_pfn_insert(vma, &pgprot, pfn)) + return VM_FAULT_SIGBUS; + insert_pfn_pmd(vma, addr, pmd, pfn, pgprot, write); + return VM_FAULT_NOPAGE; } int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm, @@ -873,16 +944,14 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm, */ if (is_huge_zero_pmd(pmd)) { struct page *zero_page; - bool set; /* * get_huge_zero_page() will never allocate a new page here, * since we already have a zero page to copy. It just takes a * reference. */ zero_page = get_huge_zero_page(); - set = set_huge_zero_page(pgtable, dst_mm, vma, addr, dst_pmd, + set_huge_zero_page(pgtable, dst_mm, vma, addr, dst_pmd, zero_page); - BUG_ON(!set); /* unexpected !pmd_none(dst_pmd) */ ret = 0; goto out_unlock; } @@ -1031,7 +1100,7 @@ static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm, goto out_free_pages; VM_BUG_ON_PAGE(!PageHead(page), page); - pmdp_clear_flush_notify(vma, haddr, pmd); + pmdp_huge_clear_flush_notify(vma, haddr, pmd); /* leave pmd empty until pte is filled */ pgtable = pgtable_trans_huge_withdraw(mm, pmd); @@ -1174,7 +1243,7 @@ alloc: pmd_t entry; entry = mk_huge_pmd(new_page, vma->vm_page_prot); entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); - pmdp_clear_flush_notify(vma, haddr, pmd); + pmdp_huge_clear_flush_notify(vma, haddr, pmd); page_add_new_anon_rmap(new_page, vma, haddr); mem_cgroup_commit_charge(new_page, memcg, false); lru_cache_add_active_or_unevictable(new_page, vma); @@ -1238,7 +1307,7 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma, pmd, _pmd, 1)) update_mmu_cache_pmd(vma, addr, pmd); } - if ((flags & FOLL_POPULATE) && (vma->vm_flags & VM_LOCKED)) { + if ((flags & FOLL_MLOCK) && (vma->vm_flags & VM_LOCKED)) { if (page->mapping && trylock_page(page)) { lru_add_drain(); if (page->mapping) @@ -1387,41 +1456,41 @@ out: int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr) { + pmd_t orig_pmd; spinlock_t *ptl; - int ret = 0; - if (__pmd_trans_huge_lock(pmd, vma, &ptl) == 1) { - struct page *page; - pgtable_t pgtable; - pmd_t orig_pmd; - /* - * For architectures like ppc64 we look at deposited pgtable - * when calling pmdp_get_and_clear. So do the - * pgtable_trans_huge_withdraw after finishing pmdp related - * operations. - */ - orig_pmd = pmdp_get_and_clear_full(tlb->mm, addr, pmd, - tlb->fullmm); - tlb_remove_pmd_tlb_entry(tlb, pmd, addr); - pgtable = pgtable_trans_huge_withdraw(tlb->mm, pmd); - if (is_huge_zero_pmd(orig_pmd)) { - atomic_long_dec(&tlb->mm->nr_ptes); - spin_unlock(ptl); + if (__pmd_trans_huge_lock(pmd, vma, &ptl) != 1) + return 0; + /* + * For architectures like ppc64 we look at deposited pgtable + * when calling pmdp_huge_get_and_clear. So do the + * pgtable_trans_huge_withdraw after finishing pmdp related + * operations. + */ + orig_pmd = pmdp_huge_get_and_clear_full(tlb->mm, addr, pmd, + tlb->fullmm); + tlb_remove_pmd_tlb_entry(tlb, pmd, addr); + if (vma_is_dax(vma)) { + spin_unlock(ptl); + if (is_huge_zero_pmd(orig_pmd)) put_huge_zero_page(); - } else { - page = pmd_page(orig_pmd); - page_remove_rmap(page); - VM_BUG_ON_PAGE(page_mapcount(page) < 0, page); - add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR); - VM_BUG_ON_PAGE(!PageHead(page), page); - atomic_long_dec(&tlb->mm->nr_ptes); - spin_unlock(ptl); - tlb_remove_page(tlb, page); - } - pte_free(tlb->mm, pgtable); - ret = 1; + } else if (is_huge_zero_pmd(orig_pmd)) { + pte_free(tlb->mm, pgtable_trans_huge_withdraw(tlb->mm, pmd)); + atomic_long_dec(&tlb->mm->nr_ptes); + spin_unlock(ptl); + put_huge_zero_page(); + } else { + struct page *page = pmd_page(orig_pmd); + page_remove_rmap(page); + VM_BUG_ON_PAGE(page_mapcount(page) < 0, page); + add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR); + VM_BUG_ON_PAGE(!PageHead(page), page); + pte_free(tlb->mm, pgtable_trans_huge_withdraw(tlb->mm, pmd)); + atomic_long_dec(&tlb->mm->nr_ptes); + spin_unlock(ptl); + tlb_remove_page(tlb, page); } - return ret; + return 1; } int move_huge_pmd(struct vm_area_struct *vma, struct vm_area_struct *new_vma, @@ -1459,7 +1528,7 @@ int move_huge_pmd(struct vm_area_struct *vma, struct vm_area_struct *new_vma, new_ptl = pmd_lockptr(mm, new_pmd); if (new_ptl != old_ptl) spin_lock_nested(new_ptl, SINGLE_DEPTH_NESTING); - pmd = pmdp_get_and_clear(mm, old_addr, old_pmd); + pmd = pmdp_huge_get_and_clear(mm, old_addr, old_pmd); VM_BUG_ON(!pmd_none(*new_pmd)); if (pmd_move_must_withdraw(new_ptl, old_ptl)) { @@ -1505,7 +1574,7 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, } if (!prot_numa || !pmd_protnone(*pmd)) { - entry = pmdp_get_and_clear_notify(mm, addr, pmd); + entry = pmdp_huge_get_and_clear_notify(mm, addr, pmd); entry = pmd_modify(entry, newprot); if (preserve_write) entry = pmd_mkwrite(entry); @@ -1676,12 +1745,7 @@ static void __split_huge_page_refcount(struct page *page, /* after clearing PageTail the gup refcount can be released */ smp_mb__after_atomic(); - /* - * retain hwpoison flag of the poisoned tail page: - * fix for the unsuitable process killed on Guest Machine(KVM) - * by the memory-failure. - */ - page_tail->flags &= ~PAGE_FLAGS_CHECK_AT_PREP | __PG_HWPOISON; + page_tail->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; page_tail->flags |= (page->flags & ((1L << PG_referenced) | (1L << PG_swapbacked) | @@ -1691,8 +1755,12 @@ static void __split_huge_page_refcount(struct page *page, (1L << PG_unevictable))); page_tail->flags |= (1L << PG_dirty); - /* clear PageTail before overwriting first_page */ - smp_wmb(); + clear_compound_head(page_tail); + + if (page_is_young(page)) + set_page_young(page_tail); + if (page_is_idle(page)) + set_page_idle(page_tail); /* * __split_huge_page_splitting() already set the @@ -1811,7 +1879,7 @@ static int __split_huge_page_map(struct page *page, * here). But it is generally safer to never allow * small and huge TLB entries for the same virtual * address to be loaded simultaneously. So instead of - * doing "pmd_populate(); flush_tlb_range();" we first + * doing "pmd_populate(); flush_pmd_tlb_range();" we first * mark the current pmd notpresent (atomically because * here the pmd_trans_huge and pmd_trans_splitting * must remain set at all times on the pmd until the @@ -1941,7 +2009,7 @@ int hugepage_madvise(struct vm_area_struct *vma, /* * Be somewhat over-protective like KSM for now! */ - if (*vm_flags & (VM_HUGEPAGE | VM_NO_THP)) + if (*vm_flags & VM_NO_THP) return -EINVAL; *vm_flags &= ~VM_NOHUGEPAGE; *vm_flags |= VM_HUGEPAGE; @@ -1957,7 +2025,7 @@ int hugepage_madvise(struct vm_area_struct *vma, /* * Be somewhat over-protective like KSM for now! */ - if (*vm_flags & (VM_NOHUGEPAGE | VM_NO_THP)) + if (*vm_flags & VM_NO_THP) return -EINVAL; *vm_flags &= ~VM_HUGEPAGE; *vm_flags |= VM_NOHUGEPAGE; @@ -2137,8 +2205,10 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, for (_pte = pte; _pte < pte+HPAGE_PMD_NR; _pte++, address += PAGE_SIZE) { pte_t pteval = *_pte; - if (pte_none(pteval) || is_zero_pfn(pte_pfn(pteval))) { - if (++none_or_zero <= khugepaged_max_ptes_none) + if (pte_none(pteval) || (pte_present(pteval) && + is_zero_pfn(pte_pfn(pteval)))) { + if (!userfaultfd_armed(vma) && + ++none_or_zero <= khugepaged_max_ptes_none) continue; else goto out; @@ -2198,7 +2268,8 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, VM_BUG_ON_PAGE(PageLRU(page), page); /* If there is no mapped pte young don't collapse the page */ - if (pte_young(pteval) || PageReferenced(page) || + if (pte_young(pteval) || + page_is_young(page) || PageReferenced(page) || mmu_notifier_test_young(vma->vm_mm, address)) referenced = true; } @@ -2262,8 +2333,12 @@ static void __collapse_huge_page_copy(pte_t *pte, struct page *page, static void khugepaged_alloc_sleep(void) { - wait_event_freezable_timeout(khugepaged_wait, false, - msecs_to_jiffies(khugepaged_alloc_sleep_millisecs)); + DEFINE_WAIT(wait); + + add_wait_queue(&khugepaged_wait, &wait); + freezable_schedule_timeout_interruptible( + msecs_to_jiffies(khugepaged_alloc_sleep_millisecs)); + remove_wait_queue(&khugepaged_wait, &wait); } static int khugepaged_node_load[MAX_NUMNODES]; @@ -2337,8 +2412,7 @@ static bool khugepaged_prealloc_page(struct page **hpage, bool *wait) static struct page * khugepaged_alloc_page(struct page **hpage, gfp_t gfp, struct mm_struct *mm, - struct vm_area_struct *vma, unsigned long address, - int node) + unsigned long address, int node) { VM_BUG_ON_PAGE(*hpage, *hpage); @@ -2350,7 +2424,7 @@ khugepaged_alloc_page(struct page **hpage, gfp_t gfp, struct mm_struct *mm, */ up_read(&mm->mmap_sem); - *hpage = alloc_pages_exact_node(node, gfp, HPAGE_PMD_ORDER); + *hpage = __alloc_pages_node(node, gfp, HPAGE_PMD_ORDER); if (unlikely(!*hpage)) { count_vm_event(THP_COLLAPSE_ALLOC_FAILED); *hpage = ERR_PTR(-ENOMEM); @@ -2405,8 +2479,7 @@ static bool khugepaged_prealloc_page(struct page **hpage, bool *wait) static struct page * khugepaged_alloc_page(struct page **hpage, gfp_t gfp, struct mm_struct *mm, - struct vm_area_struct *vma, unsigned long address, - int node) + unsigned long address, int node) { up_read(&mm->mmap_sem); VM_BUG_ON(!*hpage); @@ -2454,7 +2527,7 @@ static void collapse_huge_page(struct mm_struct *mm, __GFP_THISNODE; /* release the mmap_sem read lock. */ - new_page = khugepaged_alloc_page(hpage, gfp, mm, vma, address, node); + new_page = khugepaged_alloc_page(hpage, gfp, mm, address, node); if (!new_page) return; @@ -2499,7 +2572,7 @@ static void collapse_huge_page(struct mm_struct *mm, * huge and small TLB entries for the same virtual address * to avoid the risk of CPU bugs in that area. */ - _pmd = pmdp_clear_flush(vma, address, pmd); + _pmd = pmdp_collapse_flush(vma, address, pmd); spin_unlock(pmd_ptl); mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); @@ -2591,7 +2664,8 @@ static int khugepaged_scan_pmd(struct mm_struct *mm, _pte++, _address += PAGE_SIZE) { pte_t pteval = *_pte; if (pte_none(pteval) || is_zero_pfn(pte_pfn(pteval))) { - if (++none_or_zero <= khugepaged_max_ptes_none) + if (!userfaultfd_armed(vma) && + ++none_or_zero <= khugepaged_max_ptes_none) continue; else goto out_unmap; @@ -2624,7 +2698,8 @@ static int khugepaged_scan_pmd(struct mm_struct *mm, */ if (page_count(page) != 1 + !!PageSwapCache(page)) goto out_unmap; - if (pte_young(pteval) || PageReferenced(page) || + if (pte_young(pteval) || + page_is_young(page) || PageReferenced(page) || mmu_notifier_test_young(vma->vm_mm, address)) referenced = true; } @@ -2799,7 +2874,7 @@ static void khugepaged_do_scan(void) cond_resched(); - if (unlikely(kthread_should_stop() || freezing(current))) + if (unlikely(kthread_should_stop() || try_to_freeze())) break; spin_lock(&khugepaged_mm_lock); @@ -2820,8 +2895,6 @@ static void khugepaged_do_scan(void) static void khugepaged_wait_work(void) { - try_to_freeze(); - if (khugepaged_has_work()) { if (!khugepaged_scan_sleep_millisecs) return; @@ -2865,7 +2938,7 @@ static void __split_huge_zero_page_pmd(struct vm_area_struct *vma, pmd_t _pmd; int i; - pmdp_clear_flush_notify(vma, haddr, pmd); + pmdp_huge_clear_flush_notify(vma, haddr, pmd); /* leave pmd empty until pte is filled */ pgtable = pgtable_trans_huge_withdraw(mm, pmd); @@ -2889,7 +2962,7 @@ void __split_huge_page_pmd(struct vm_area_struct *vma, unsigned long address, pmd_t *pmd) { spinlock_t *ptl; - struct page *page; + struct page *page = NULL; struct mm_struct *mm = vma->vm_mm; unsigned long haddr = address & HPAGE_PMD_MASK; unsigned long mmun_start; /* For mmu_notifiers */ @@ -2902,25 +2975,27 @@ void __split_huge_page_pmd(struct vm_area_struct *vma, unsigned long address, again: mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end); ptl = pmd_lock(mm, pmd); - if (unlikely(!pmd_trans_huge(*pmd))) { - spin_unlock(ptl); - mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); - return; - } - if (is_huge_zero_pmd(*pmd)) { + if (unlikely(!pmd_trans_huge(*pmd))) + goto unlock; + if (vma_is_dax(vma)) { + pmd_t _pmd = pmdp_huge_clear_flush_notify(vma, haddr, pmd); + if (is_huge_zero_pmd(_pmd)) + put_huge_zero_page(); + } else if (is_huge_zero_pmd(*pmd)) { __split_huge_zero_page_pmd(vma, haddr, pmd); - spin_unlock(ptl); - mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); - return; + } else { + page = pmd_page(*pmd); + VM_BUG_ON_PAGE(!page_count(page), page); + get_page(page); } - page = pmd_page(*pmd); - VM_BUG_ON_PAGE(!page_count(page), page); - get_page(page); + unlock: spin_unlock(ptl); mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); - split_huge_page(page); + if (!page) + return; + split_huge_page(page); put_page(page); /* @@ -2969,7 +3044,7 @@ static void split_huge_page_address(struct mm_struct *mm, split_huge_page_pmd_mm(mm, address, pmd); } -void __vma_adjust_trans_huge(struct vm_area_struct *vma, +void vma_adjust_trans_huge(struct vm_area_struct *vma, unsigned long start, unsigned long end, long adjust_next)