diff options
Diffstat (limited to 'mm/huge_memory.c')
| -rw-r--r-- | mm/huge_memory.c | 440 |
1 files changed, 210 insertions, 230 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 141dbb695097..a863af26c79c 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -102,10 +102,7 @@ static int set_recommended_min_free_kbytes(void) unsigned long recommended_min; extern int min_free_kbytes; - if (!test_bit(TRANSPARENT_HUGEPAGE_FLAG, - &transparent_hugepage_flags) && - !test_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, - &transparent_hugepage_flags)) + if (!khugepaged_enabled()) return 0; for_each_populated_zone(zone) @@ -139,12 +136,6 @@ static int start_khugepaged(void) { int err = 0; if (khugepaged_enabled()) { - int wakeup; - if (unlikely(!mm_slot_cache || !mm_slots_hash)) { - err = -ENOMEM; - goto out; - } - mutex_lock(&khugepaged_mutex); if (!khugepaged_thread) khugepaged_thread = kthread_run(khugepaged, NULL, "khugepaged"); @@ -154,16 +145,16 @@ static int start_khugepaged(void) err = PTR_ERR(khugepaged_thread); khugepaged_thread = NULL; } - wakeup = !list_empty(&khugepaged_scan.mm_head); - mutex_unlock(&khugepaged_mutex); - if (wakeup) + + if (!list_empty(&khugepaged_scan.mm_head)) wake_up_interruptible(&khugepaged_wait); set_recommended_min_free_kbytes(); - } else - /* wakeup to exit */ - wake_up_interruptible(&khugepaged_wait); -out: + } else if (khugepaged_thread) { + kthread_stop(khugepaged_thread); + khugepaged_thread = NULL; + } + return err; } @@ -224,18 +215,16 @@ static ssize_t enabled_store(struct kobject *kobj, TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG); if (ret > 0) { - int err = start_khugepaged(); + int err; + + mutex_lock(&khugepaged_mutex); + err = start_khugepaged(); + mutex_unlock(&khugepaged_mutex); + if (err) ret = err; } - if (ret > 0 && - (test_bit(TRANSPARENT_HUGEPAGE_FLAG, - &transparent_hugepage_flags) || - test_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, - &transparent_hugepage_flags))) - set_recommended_min_free_kbytes(); - return ret; } static struct kobj_attribute enabled_attr = @@ -570,8 +559,6 @@ static int __init hugepage_init(void) start_khugepaged(); - set_recommended_min_free_kbytes(); - return 0; out: hugepage_exit_sysfs(hugepage_kobj); @@ -611,19 +598,6 @@ out: } __setup("transparent_hugepage=", setup_transparent_hugepage); -static void prepare_pmd_huge_pte(pgtable_t pgtable, - struct mm_struct *mm) -{ - assert_spin_locked(&mm->page_table_lock); - - /* FIFO */ - if (!mm->pmd_huge_pte) - INIT_LIST_HEAD(&pgtable->lru); - else - list_add(&pgtable->lru, &mm->pmd_huge_pte->lru); - mm->pmd_huge_pte = pgtable; -} - static inline pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) { if (likely(vma->vm_flags & VM_WRITE)) @@ -665,7 +639,7 @@ static int __do_huge_pmd_anonymous_page(struct mm_struct *mm, */ page_add_new_anon_rmap(page, vma, haddr); set_pmd_at(mm, haddr, pmd, entry); - prepare_pmd_huge_pte(pgtable, mm); + pgtable_trans_huge_deposit(mm, pgtable); add_mm_counter(mm, MM_ANONPAGES, HPAGE_PMD_NR); mm->nr_ptes++; spin_unlock(&mm->page_table_lock); @@ -791,7 +765,7 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm, pmdp_set_wrprotect(src_mm, addr, src_pmd); pmd = pmd_mkold(pmd_wrprotect(pmd)); set_pmd_at(dst_mm, addr, dst_pmd, pmd); - prepare_pmd_huge_pte(pgtable, dst_mm); + pgtable_trans_huge_deposit(dst_mm, pgtable); dst_mm->nr_ptes++; ret = 0; @@ -802,25 +776,6 @@ out: return ret; } -/* no "address" argument so destroys page coloring of some arch */ -pgtable_t get_pmd_huge_pte(struct mm_struct *mm) -{ - pgtable_t pgtable; - - assert_spin_locked(&mm->page_table_lock); - - /* FIFO */ - pgtable = mm->pmd_huge_pte; - if (list_empty(&pgtable->lru)) - mm->pmd_huge_pte = NULL; - else { - mm->pmd_huge_pte = list_entry(pgtable->lru.next, - struct page, lru); - list_del(&pgtable->lru); - } - return pgtable; -} - static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, @@ -832,6 +787,8 @@ static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm, pmd_t _pmd; int ret = 0, i; struct page **pages; + unsigned long mmun_start; /* For mmu_notifiers */ + unsigned long mmun_end; /* For mmu_notifiers */ pages = kmalloc(sizeof(struct page *) * HPAGE_PMD_NR, GFP_KERNEL); @@ -868,15 +825,19 @@ static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm, cond_resched(); } + mmun_start = haddr; + mmun_end = haddr + HPAGE_PMD_SIZE; + mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end); + spin_lock(&mm->page_table_lock); if (unlikely(!pmd_same(*pmd, orig_pmd))) goto out_free_pages; VM_BUG_ON(!PageHead(page)); - pmdp_clear_flush_notify(vma, haddr, pmd); + pmdp_clear_flush(vma, haddr, pmd); /* leave pmd empty until pte is filled */ - pgtable = get_pmd_huge_pte(mm); + pgtable = pgtable_trans_huge_withdraw(mm); pmd_populate(mm, &_pmd, pgtable); for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) { @@ -896,6 +857,8 @@ static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm, page_remove_rmap(page); spin_unlock(&mm->page_table_lock); + mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); + ret |= VM_FAULT_WRITE; put_page(page); @@ -904,6 +867,7 @@ out: out_free_pages: spin_unlock(&mm->page_table_lock); + mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); mem_cgroup_uncharge_start(); for (i = 0; i < HPAGE_PMD_NR; i++) { mem_cgroup_uncharge_page(pages[i]); @@ -920,6 +884,8 @@ int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, int ret = 0; struct page *page, *new_page; unsigned long haddr; + unsigned long mmun_start; /* For mmu_notifiers */ + unsigned long mmun_end; /* For mmu_notifiers */ VM_BUG_ON(!vma->anon_vma); spin_lock(&mm->page_table_lock); @@ -934,7 +900,7 @@ int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, entry = pmd_mkyoung(orig_pmd); entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); if (pmdp_set_access_flags(vma, haddr, pmd, entry, 1)) - update_mmu_cache(vma, address, entry); + update_mmu_cache_pmd(vma, address, pmd); ret |= VM_FAULT_WRITE; goto out_unlock; } @@ -970,38 +936,47 @@ int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, copy_user_huge_page(new_page, page, haddr, vma, HPAGE_PMD_NR); __SetPageUptodate(new_page); + mmun_start = haddr; + mmun_end = haddr + HPAGE_PMD_SIZE; + mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end); + spin_lock(&mm->page_table_lock); put_page(page); if (unlikely(!pmd_same(*pmd, orig_pmd))) { spin_unlock(&mm->page_table_lock); mem_cgroup_uncharge_page(new_page); put_page(new_page); - goto out; + goto out_mn; } else { pmd_t entry; VM_BUG_ON(!PageHead(page)); entry = mk_pmd(new_page, vma->vm_page_prot); entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); entry = pmd_mkhuge(entry); - pmdp_clear_flush_notify(vma, haddr, pmd); + pmdp_clear_flush(vma, haddr, pmd); page_add_new_anon_rmap(new_page, vma, haddr); set_pmd_at(mm, haddr, pmd, entry); - update_mmu_cache(vma, address, entry); + update_mmu_cache_pmd(vma, address, pmd); page_remove_rmap(page); put_page(page); ret |= VM_FAULT_WRITE; } -out_unlock: spin_unlock(&mm->page_table_lock); +out_mn: + mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); out: return ret; +out_unlock: + spin_unlock(&mm->page_table_lock); + return ret; } -struct page *follow_trans_huge_pmd(struct mm_struct *mm, +struct page *follow_trans_huge_pmd(struct vm_area_struct *vma, unsigned long addr, pmd_t *pmd, unsigned int flags) { + struct mm_struct *mm = vma->vm_mm; struct page *page = NULL; assert_spin_locked(&mm->page_table_lock); @@ -1024,6 +999,14 @@ struct page *follow_trans_huge_pmd(struct mm_struct *mm, _pmd = pmd_mkyoung(pmd_mkdirty(*pmd)); set_pmd_at(mm, addr & HPAGE_PMD_MASK, pmd, _pmd); } + if ((flags & FOLL_MLOCK) && (vma->vm_flags & VM_LOCKED)) { + if (page->mapping && trylock_page(page)) { + lru_add_drain(); + if (page->mapping) + mlock_vma_page(page); + unlock_page(page); + } + } page += (addr & ~HPAGE_PMD_MASK) >> PAGE_SHIFT; VM_BUG_ON(!PageCompound(page)); if (flags & FOLL_GET) @@ -1041,9 +1024,10 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, if (__pmd_trans_huge_lock(pmd, vma) == 1) { struct page *page; pgtable_t pgtable; - pgtable = get_pmd_huge_pte(tlb->mm); - page = pmd_page(*pmd); - pmd_clear(pmd); + pmd_t orig_pmd; + pgtable = pgtable_trans_huge_withdraw(tlb->mm); + orig_pmd = pmdp_get_and_clear(tlb->mm, addr, pmd); + page = pmd_page(orig_pmd); tlb_remove_pmd_tlb_entry(tlb, pmd, addr); page_remove_rmap(page); VM_BUG_ON(page_mapcount(page) < 0); @@ -1207,7 +1191,11 @@ static int __split_huge_page_splitting(struct page *page, struct mm_struct *mm = vma->vm_mm; pmd_t *pmd; int ret = 0; + /* For mmu_notifiers */ + const unsigned long mmun_start = address; + const unsigned long mmun_end = address + HPAGE_PMD_SIZE; + mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end); spin_lock(&mm->page_table_lock); pmd = page_check_address_pmd(page, mm, address, PAGE_CHECK_ADDRESS_PMD_NOTSPLITTING_FLAG); @@ -1219,10 +1207,11 @@ static int __split_huge_page_splitting(struct page *page, * and it won't wait on the anon_vma->root->mutex to * serialize against split_huge_page*. */ - pmdp_splitting_flush_notify(vma, address, pmd); + pmdp_splitting_flush(vma, address, pmd); ret = 1; } spin_unlock(&mm->page_table_lock); + mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); return ret; } @@ -1358,11 +1347,11 @@ static int __split_huge_page_map(struct page *page, pmd = page_check_address_pmd(page, mm, address, PAGE_CHECK_ADDRESS_PMD_SPLITTING_FLAG); if (pmd) { - pgtable = get_pmd_huge_pte(mm); + pgtable = pgtable_trans_huge_withdraw(mm); pmd_populate(mm, &_pmd, pgtable); - for (i = 0, haddr = address; i < HPAGE_PMD_NR; - i++, haddr += PAGE_SIZE) { + haddr = address; + for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) { pte_t *pte, entry; BUG_ON(PageCompound(page+i)); entry = mk_pte(page + i, vma->vm_page_prot); @@ -1406,8 +1395,7 @@ static int __split_huge_page_map(struct page *page, * SMP TLB and finally we write the non-huge version * of the pmd entry with pmd_populate. */ - set_pmd_at(mm, address, pmd, pmd_mknotpresent(*pmd)); - flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE); + pmdp_invalidate(vma, address, pmd); pmd_populate(mm, pmd, pgtable); ret = 1; } @@ -1421,18 +1409,17 @@ static void __split_huge_page(struct page *page, struct anon_vma *anon_vma) { int mapcount, mapcount2; + pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); struct anon_vma_chain *avc; BUG_ON(!PageHead(page)); BUG_ON(PageTail(page)); mapcount = 0; - list_for_each_entry(avc, &anon_vma->head, same_anon_vma) { + anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root, pgoff, pgoff) { struct vm_area_struct *vma = avc->vma; unsigned long addr = vma_address(page, vma); BUG_ON(is_vma_temporary_stack(vma)); - if (addr == -EFAULT) - continue; mapcount += __split_huge_page_splitting(page, vma, addr); } /* @@ -1453,12 +1440,10 @@ static void __split_huge_page(struct page *page, __split_huge_page_refcount(page); mapcount2 = 0; - list_for_each_entry(avc, &anon_vma->head, same_anon_vma) { + anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root, pgoff, pgoff) { struct vm_area_struct *vma = avc->vma; unsigned long addr = vma_address(page, vma); BUG_ON(is_vma_temporary_stack(vma)); - if (addr == -EFAULT) - continue; mapcount2 += __split_huge_page_map(page, vma, addr); } if (mapcount != mapcount2) @@ -1491,12 +1476,13 @@ out: return ret; } -#define VM_NO_THP (VM_SPECIAL|VM_INSERTPAGE|VM_MIXEDMAP|VM_SAO| \ - VM_HUGETLB|VM_SHARED|VM_MAYSHARE) +#define VM_NO_THP (VM_SPECIAL|VM_MIXEDMAP|VM_HUGETLB|VM_SHARED|VM_MAYSHARE) int hugepage_madvise(struct vm_area_struct *vma, unsigned long *vm_flags, int advice) { + struct mm_struct *mm = vma->vm_mm; + switch (advice) { case MADV_HUGEPAGE: /* @@ -1504,6 +1490,8 @@ int hugepage_madvise(struct vm_area_struct *vma, */ if (*vm_flags & (VM_HUGEPAGE | VM_NO_THP)) return -EINVAL; + if (mm->def_flags & VM_NOHUGEPAGE) + return -EINVAL; *vm_flags &= ~VM_NOHUGEPAGE; *vm_flags |= VM_HUGEPAGE; /* @@ -1655,11 +1643,7 @@ int khugepaged_enter_vma_merge(struct vm_area_struct *vma) if (vma->vm_ops) /* khugepaged not yet working on file or special mappings */ return 0; - /* - * If is_pfn_mapping() is true is_learn_pfn_mapping() must be - * true too, verify it here. - */ - VM_BUG_ON(is_linear_pfn_mapping(vma) || vma->vm_flags & VM_NO_THP); + VM_BUG_ON(vma->vm_flags & VM_NO_THP); hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK; hend = vma->vm_end & HPAGE_PMD_MASK; if (hstart < hend) @@ -1833,28 +1817,35 @@ static void __collapse_huge_page_copy(pte_t *pte, struct page *page, } } -static void collapse_huge_page(struct mm_struct *mm, - unsigned long address, - struct page **hpage, - struct vm_area_struct *vma, - int node) +static void khugepaged_alloc_sleep(void) { - pgd_t *pgd; - pud_t *pud; - pmd_t *pmd, _pmd; - pte_t *pte; - pgtable_t pgtable; - struct page *new_page; - spinlock_t *ptl; - int isolated; - unsigned long hstart, hend; + wait_event_freezable_timeout(khugepaged_wait, false, + msecs_to_jiffies(khugepaged_alloc_sleep_millisecs)); +} - VM_BUG_ON(address & ~HPAGE_PMD_MASK); -#ifndef CONFIG_NUMA - up_read(&mm->mmap_sem); - VM_BUG_ON(!*hpage); - new_page = *hpage; -#else +#ifdef CONFIG_NUMA +static bool khugepaged_prealloc_page(struct page **hpage, bool *wait) +{ + if (IS_ERR(*hpage)) { + if (!*wait) + return false; + + *wait = false; + *hpage = NULL; + khugepaged_alloc_sleep(); + } else if (*hpage) { + put_page(*hpage); + *hpage = NULL; + } + + return true; +} + +static struct page +*khugepaged_alloc_page(struct page **hpage, struct mm_struct *mm, + struct vm_area_struct *vma, unsigned long address, + int node) +{ VM_BUG_ON(*hpage); /* * Allocate the page while the vma is still valid and under @@ -1866,7 +1857,7 @@ static void collapse_huge_page(struct mm_struct *mm, * mmap_sem in read mode is good idea also to allow greater * scalability. */ - new_page = alloc_hugepage_vma(khugepaged_defrag(), vma, address, + *hpage = alloc_hugepage_vma(khugepaged_defrag(), vma, address, node, __GFP_OTHER_NODE); /* @@ -1874,20 +1865,85 @@ static void collapse_huge_page(struct mm_struct *mm, * preparation for taking it in write mode. */ up_read(&mm->mmap_sem); - if (unlikely(!new_page)) { + if (unlikely(!*hpage)) { count_vm_event(THP_COLLAPSE_ALLOC_FAILED); *hpage = ERR_PTR(-ENOMEM); - return; + return NULL; } -#endif count_vm_event(THP_COLLAPSE_ALLOC); - if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) { -#ifdef CONFIG_NUMA - put_page(new_page); + return *hpage; +} +#else +static struct page *khugepaged_alloc_hugepage(bool *wait) +{ + struct page *hpage; + + do { + hpage = alloc_hugepage(khugepaged_defrag()); + if (!hpage) { + count_vm_event(THP_COLLAPSE_ALLOC_FAILED); + if (!*wait) + return NULL; + + *wait = false; + khugepaged_alloc_sleep(); + } else + count_vm_event(THP_COLLAPSE_ALLOC); + } while (unlikely(!hpage) && likely(khugepaged_enabled())); + + return hpage; +} + +static bool khugepaged_prealloc_page(struct page **hpage, bool *wait) +{ + if (!*hpage) + *hpage = khugepaged_alloc_hugepage(wait); + + if (unlikely(!*hpage)) + return false; + + return true; +} + +static struct page +*khugepaged_alloc_page(struct page **hpage, struct mm_struct *mm, + struct vm_area_struct *vma, unsigned long address, + int node) +{ + up_read(&mm->mmap_sem); + VM_BUG_ON(!*hpage); + return *hpage; +} #endif + +static void collapse_huge_page(struct mm_struct *mm, + unsigned long address, + struct page **hpage, + struct vm_area_struct *vma, + int node) +{ + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd, _pmd; + pte_t *pte; + pgtable_t pgtable; + struct page *new_page; + spinlock_t *ptl; + int isolated; + unsigned long hstart, hend; + unsigned long mmun_start; /* For mmu_notifiers */ + unsigned long mmun_end; /* For mmu_notifiers */ + + VM_BUG_ON(address & ~HPAGE_PMD_MASK); + + /* release the mmap_sem read lock. */ + new_page = khugepaged_alloc_page(hpage, mm, vma, address, node); + if (!new_page) + return; + + if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) return; - } /* * Prevent all access to pagetables with the exception of @@ -1912,11 +1968,7 @@ static void collapse_huge_page(struct mm_struct *mm, goto out; if (is_vma_temporary_stack(vma)) goto out; - /* - * If is_pfn_mapping() is true is_learn_pfn_mapping() must be - * true too, verify it here. - */ - VM_BUG_ON(is_linear_pfn_mapping(vma) || vma->vm_flags & VM_NO_THP); + VM_BUG_ON(vma->vm_flags & VM_NO_THP); pgd = pgd_offset(mm, address); if (!pgd_present(*pgd)) @@ -1936,6 +1988,9 @@ static void collapse_huge_page(struct mm_struct *mm, pte = pte_offset_map(pmd, address); ptl = pte_lockptr(mm, pmd); + mmun_start = address; + mmun_end = address + HPAGE_PMD_SIZE; + mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end); spin_lock(&mm->page_table_lock); /* probably unnecessary */ /* * After this gup_fast can't run anymore. This also removes @@ -1943,8 +1998,9 @@ 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_notify(vma, address, pmd); + _pmd = pmdp_clear_flush(vma, address, pmd); spin_unlock(&mm->page_table_lock); + mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); spin_lock(ptl); isolated = __collapse_huge_page_isolate(vma, address, pte); @@ -1970,8 +2026,6 @@ static void collapse_huge_page(struct mm_struct *mm, pte_unmap(pte); __SetPageUptodate(new_page); pgtable = pmd_pgtable(_pmd); - VM_BUG_ON(page_count(pgtable) != 1); - VM_BUG_ON(page_mapcount(pgtable) != 0); _pmd = mk_pmd(new_page, vma->vm_page_prot); _pmd = maybe_pmd_mkwrite(pmd_mkdirty(_pmd), vma); @@ -1988,13 +2042,12 @@ static void collapse_huge_page(struct mm_struct *mm, BUG_ON(!pmd_none(*pmd)); page_add_new_anon_rmap(new_page, vma, address); set_pmd_at(mm, address, pmd, _pmd); - update_mmu_cache(vma, address, _pmd); - prepare_pmd_huge_pte(pgtable, mm); + update_mmu_cache_pmd(vma, address, pmd); + pgtable_trans_huge_deposit(mm, pgtable); spin_unlock(&mm->page_table_lock); -#ifndef CONFIG_NUMA *hpage = NULL; -#endif + khugepaged_pages_collapsed++; out_up_write: up_write(&mm->mmap_sem); @@ -2002,9 +2055,6 @@ out_up_write: out: mem_cgroup_uncharge_page(new_page); -#ifdef CONFIG_NUMA - put_page(new_page); -#endif goto out_up_write; } @@ -2154,12 +2204,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, goto skip; if (is_vma_temporary_stack(vma)) goto skip; - /* - * If is_pfn_mapping() is true is_learn_pfn_mapping() - * must be true too, verify it here. - */ - VM_BUG_ON(is_linear_pfn_mapping(vma) || - vma->vm_flags & VM_NO_THP); + VM_BUG_ON(vma->vm_flags & VM_NO_THP); hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK; hend = vma->vm_end & HPAGE_PMD_MASK; @@ -2234,32 +2279,23 @@ static int khugepaged_has_work(void) static int khugepaged_wait_event(void) { return !list_empty(&khugepaged_scan.mm_head) || - !khugepaged_enabled(); + kthread_should_stop(); } -static void khugepaged_do_scan(struct page **hpage) +static void khugepaged_do_scan(void) { + struct page *hpage = NULL; unsigned int progress = 0, pass_through_head = 0; unsigned int pages = khugepaged_pages_to_scan; + bool wait = true; barrier(); /* write khugepaged_pages_to_scan to local stack */ while (progress < pages) { - cond_resched(); - -#ifndef CONFIG_NUMA - if (!*hpage) { - *hpage = alloc_hugepage(khugepaged_defrag()); - if (unlikely(!*hpage)) { - count_vm_event(THP_COLLAPSE_ALLOC_FAILED); - break; - } - count_vm_event(THP_COLLAPSE_ALLOC); - } -#else - if (IS_ERR(*hpage)) + if (!khugepaged_prealloc_page(&hpage, &wait)) break; -#endif + + cond_resched(); if (unlikely(kthread_should_stop() || freezing(current))) break; @@ -2270,73 +2306,32 @@ static void khugepaged_do_scan(struct page **hpage) if (khugepaged_has_work() && pass_through_head < 2) progress += khugepaged_scan_mm_slot(pages - progress, - hpage); + &hpage); else progress = pages; spin_unlock(&khugepaged_mm_lock); } -} -static void khugepaged_alloc_sleep(void) -{ - wait_event_freezable_timeout(khugepaged_wait, false, - msecs_to_jiffies(khugepaged_alloc_sleep_millisecs)); + if (!IS_ERR_OR_NULL(hpage)) + put_page(hpage); } -#ifndef CONFIG_NUMA -static struct page *khugepaged_alloc_hugepage(void) +static void khugepaged_wait_work(void) { - struct page *hpage; - - do { - hpage = alloc_hugepage(khugepaged_defrag()); - if (!hpage) { - count_vm_event(THP_COLLAPSE_ALLOC_FAILED); - khugepaged_alloc_sleep(); - } else - count_vm_event(THP_COLLAPSE_ALLOC); - } while (unlikely(!hpage) && - likely(khugepaged_enabled())); - return hpage; -} -#endif + try_to_freeze(); -static void khugepaged_loop(void) -{ - struct page *hpage; + if (khugepaged_has_work()) { + if (!khugepaged_scan_sleep_millisecs) + return; -#ifdef CONFIG_NUMA - hpage = NULL; -#endif - while (likely(khugepaged_enabled())) { -#ifndef CONFIG_NUMA - hpage = khugepaged_alloc_hugepage(); - if (unlikely(!hpage)) - break; -#else - if (IS_ERR(hpage)) { - khugepaged_alloc_sleep(); - hpage = NULL; - } -#endif - - khugepaged_do_scan(&hpage); -#ifndef CONFIG_NUMA - if (hpage) - put_page(hpage); -#endif - try_to_freeze(); - if (unlikely(kthread_should_stop())) - break; - if (khugepaged_has_work()) { - if (!khugepaged_scan_sleep_millisecs) - continue; - wait_event_freezable_timeout(khugepaged_wait, false, - msecs_to_jiffies(khugepaged_scan_sleep_millisecs)); - } else if (khugepaged_enabled()) - wait_event_freezable(khugepaged_wait, - khugepaged_wait_event()); + wait_event_freezable_timeout(khugepaged_wait, + kthread_should_stop(), + msecs_to_jiffies(khugepaged_scan_sleep_millisecs)); + return; } + + if (khugepaged_enabled()) + wait_event_freezable(khugepaged_wait, khugepaged_wait_event()); } static int khugepaged(void *none) @@ -2346,20 +2341,9 @@ static int khugepaged(void *none) set_freezable(); set_user_nice(current, 19); - /* serialize with start_khugepaged() */ - mutex_lock(&khugepaged_mutex); - - for (;;) { - mutex_unlock(&khugepaged_mutex); - VM_BUG_ON(khugepaged_thread != current); - khugepaged_loop(); - VM_BUG_ON(khugepaged_thread != current); - - mutex_lock(&khugepaged_mutex); - if (!khugepaged_enabled()) - break; - if (unlikely(kthread_should_stop())) - break; + while (!kthread_should_stop()) { + khugepaged_do_scan(); + khugepaged_wait_work(); } spin_lock(&khugepaged_mm_lock); @@ -2368,10 +2352,6 @@ static int khugepaged(void *none) if (mm_slot) collect_mm_slot(mm_slot); spin_unlock(&khugepaged_mm_lock); - - khugepaged_thread = NULL; - mutex_unlock(&khugepaged_mutex); - return 0; } |