diff options
Diffstat (limited to 'mm/khugepaged.c')
| -rw-r--r-- | mm/khugepaged.c | 334 |
1 files changed, 213 insertions, 121 deletions
diff --git a/mm/khugepaged.c b/mm/khugepaged.c index cd280afb246e..b043c40a21d4 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -28,6 +28,8 @@ enum scan_result { SCAN_SUCCEED, SCAN_PMD_NULL, SCAN_EXCEED_NONE_PTE, + SCAN_EXCEED_SWAP_PTE, + SCAN_EXCEED_SHARED_PTE, SCAN_PTE_NON_PRESENT, SCAN_PTE_UFFD_WP, SCAN_PAGE_RO, @@ -47,7 +49,6 @@ enum scan_result { SCAN_DEL_PAGE_LRU, SCAN_ALLOC_HUGE_PAGE_FAIL, SCAN_CGROUP_CHARGE_FAIL, - SCAN_EXCEED_SWAP_PTE, SCAN_TRUNCATED, SCAN_PAGE_HAS_PRIVATE, }; @@ -72,6 +73,7 @@ static DECLARE_WAIT_QUEUE_HEAD(khugepaged_wait); */ static unsigned int khugepaged_max_ptes_none __read_mostly; static unsigned int khugepaged_max_ptes_swap __read_mostly; +static unsigned int khugepaged_max_ptes_shared __read_mostly; #define MM_SLOTS_HASH_BITS 10 static __read_mostly DEFINE_HASHTABLE(mm_slots_hash, MM_SLOTS_HASH_BITS); @@ -291,15 +293,43 @@ static struct kobj_attribute khugepaged_max_ptes_swap_attr = __ATTR(max_ptes_swap, 0644, khugepaged_max_ptes_swap_show, khugepaged_max_ptes_swap_store); +static ssize_t khugepaged_max_ptes_shared_show(struct kobject *kobj, + struct kobj_attribute *attr, + char *buf) +{ + return sprintf(buf, "%u\n", khugepaged_max_ptes_shared); +} + +static ssize_t khugepaged_max_ptes_shared_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + int err; + unsigned long max_ptes_shared; + + err = kstrtoul(buf, 10, &max_ptes_shared); + if (err || max_ptes_shared > HPAGE_PMD_NR-1) + return -EINVAL; + + khugepaged_max_ptes_shared = max_ptes_shared; + + return count; +} + +static struct kobj_attribute khugepaged_max_ptes_shared_attr = + __ATTR(max_ptes_shared, 0644, khugepaged_max_ptes_shared_show, + khugepaged_max_ptes_shared_store); + static struct attribute *khugepaged_attr[] = { &khugepaged_defrag_attr.attr, &khugepaged_max_ptes_none_attr.attr, + &khugepaged_max_ptes_swap_attr.attr, + &khugepaged_max_ptes_shared_attr.attr, &pages_to_scan_attr.attr, &pages_collapsed_attr.attr, &full_scans_attr.attr, &scan_sleep_millisecs_attr.attr, &alloc_sleep_millisecs_attr.attr, - &khugepaged_max_ptes_swap_attr.attr, NULL, }; @@ -359,6 +389,7 @@ int __init khugepaged_init(void) khugepaged_pages_to_scan = HPAGE_PMD_NR * 8; khugepaged_max_ptes_none = HPAGE_PMD_NR - 1; khugepaged_max_ptes_swap = HPAGE_PMD_NR / 8; + khugepaged_max_ptes_shared = HPAGE_PMD_NR / 2; return 0; } @@ -503,36 +534,61 @@ void __khugepaged_exit(struct mm_struct *mm) * under mmap sem read mode). Stop here (after we * return all pagetables will be destroyed) until * khugepaged has finished working on the pagetables - * under the mmap_sem. + * under the mmap_lock. */ - down_write(&mm->mmap_sem); - up_write(&mm->mmap_sem); + mmap_write_lock(mm); + mmap_write_unlock(mm); } } static void release_pte_page(struct page *page) { - dec_node_page_state(page, NR_ISOLATED_ANON + page_is_file_lru(page)); + mod_node_page_state(page_pgdat(page), + NR_ISOLATED_ANON + page_is_file_lru(page), + -compound_nr(page)); unlock_page(page); putback_lru_page(page); } -static void release_pte_pages(pte_t *pte, pte_t *_pte) +static void release_pte_pages(pte_t *pte, pte_t *_pte, + struct list_head *compound_pagelist) { + struct page *page, *tmp; + while (--_pte >= pte) { pte_t pteval = *_pte; - if (!pte_none(pteval) && !is_zero_pfn(pte_pfn(pteval))) - release_pte_page(pte_page(pteval)); + + page = pte_page(pteval); + if (!pte_none(pteval) && !is_zero_pfn(pte_pfn(pteval)) && + !PageCompound(page)) + release_pte_page(page); + } + + list_for_each_entry_safe(page, tmp, compound_pagelist, lru) { + list_del(&page->lru); + release_pte_page(page); } } +static bool is_refcount_suitable(struct page *page) +{ + int expected_refcount; + + expected_refcount = total_mapcount(page); + if (PageSwapCache(page)) + expected_refcount += compound_nr(page); + + return page_count(page) == expected_refcount; +} + static int __collapse_huge_page_isolate(struct vm_area_struct *vma, unsigned long address, - pte_t *pte) + pte_t *pte, + struct list_head *compound_pagelist) { struct page *page = NULL; pte_t *_pte; - int none_or_zero = 0, result = 0, referenced = 0; + int none_or_zero = 0, shared = 0, result = 0, referenced = 0; bool writable = false; for (_pte = pte; _pte < pte+HPAGE_PMD_NR; @@ -558,13 +614,27 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, goto out; } - /* TODO: teach khugepaged to collapse THP mapped with pte */ - if (PageCompound(page)) { - result = SCAN_PAGE_COMPOUND; + VM_BUG_ON_PAGE(!PageAnon(page), page); + + if (page_mapcount(page) > 1 && + ++shared > khugepaged_max_ptes_shared) { + result = SCAN_EXCEED_SHARED_PTE; goto out; } - VM_BUG_ON_PAGE(!PageAnon(page), page); + if (PageCompound(page)) { + struct page *p; + page = compound_head(page); + + /* + * Check if we have dealt with the compound page + * already + */ + list_for_each_entry(p, compound_pagelist, lru) { + if (page == p) + goto next; + } + } /* * We can do it before isolate_lru_page because the @@ -578,28 +648,30 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, } /* - * cannot use mapcount: can't collapse if there's a gup pin. - * The page must only be referenced by the scanned process - * and page swap cache. + * Check if the page has any GUP (or other external) pins. + * + * The page table that maps the page has been already unlinked + * from the page table tree and this process cannot get + * an additinal pin on the page. + * + * New pins can come later if the page is shared across fork, + * but not from this process. The other process cannot write to + * the page, only trigger CoW. */ - if (page_count(page) != 1 + PageSwapCache(page)) { + if (!is_refcount_suitable(page)) { unlock_page(page); result = SCAN_PAGE_COUNT; goto out; } - if (pte_write(pteval)) { - writable = true; - } else { - if (PageSwapCache(page) && - !reuse_swap_page(page, NULL)) { - unlock_page(page); - result = SCAN_SWAP_CACHE_PAGE; - goto out; - } + if (!pte_write(pteval) && PageSwapCache(page) && + !reuse_swap_page(page, NULL)) { /* - * Page is not in the swap cache. It can be collapsed - * into a THP. + * Page is in the swap cache and cannot be re-used. + * It cannot be collapsed into a THP. */ + unlock_page(page); + result = SCAN_SWAP_CACHE_PAGE; + goto out; } /* @@ -611,16 +683,23 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, result = SCAN_DEL_PAGE_LRU; goto out; } - inc_node_page_state(page, - NR_ISOLATED_ANON + page_is_file_lru(page)); + mod_node_page_state(page_pgdat(page), + NR_ISOLATED_ANON + page_is_file_lru(page), + compound_nr(page)); VM_BUG_ON_PAGE(!PageLocked(page), page); VM_BUG_ON_PAGE(PageLRU(page), page); + if (PageCompound(page)) + list_add_tail(&page->lru, compound_pagelist); +next: /* There should be enough young pte to collapse the page */ if (pte_young(pteval) || page_is_young(page) || PageReferenced(page) || mmu_notifier_test_young(vma->vm_mm, address)) referenced++; + + if (pte_write(pteval)) + writable = true; } if (likely(writable)) { if (likely(referenced)) { @@ -634,7 +713,7 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, } out: - release_pte_pages(pte, _pte); + release_pte_pages(pte, _pte, compound_pagelist); trace_mm_collapse_huge_page_isolate(page, none_or_zero, referenced, writable, result); return 0; @@ -643,13 +722,14 @@ out: static void __collapse_huge_page_copy(pte_t *pte, struct page *page, struct vm_area_struct *vma, unsigned long address, - spinlock_t *ptl) + spinlock_t *ptl, + struct list_head *compound_pagelist) { + struct page *src_page, *tmp; pte_t *_pte; for (_pte = pte; _pte < pte + HPAGE_PMD_NR; _pte++, page++, address += PAGE_SIZE) { pte_t pteval = *_pte; - struct page *src_page; if (pte_none(pteval) || is_zero_pfn(pte_pfn(pteval))) { clear_user_highpage(page, address); @@ -669,8 +749,8 @@ static void __collapse_huge_page_copy(pte_t *pte, struct page *page, } else { src_page = pte_page(pteval); copy_user_highpage(page, src_page, address, vma); - VM_BUG_ON_PAGE(page_mapcount(src_page) != 1, src_page); - release_pte_page(src_page); + if (!PageCompound(src_page)) + release_pte_page(src_page); /* * ptl mostly unnecessary, but preempt has to * be disabled to update the per-cpu stats @@ -687,6 +767,11 @@ static void __collapse_huge_page_copy(pte_t *pte, struct page *page, free_page_and_swap_cache(src_page); } } + + list_for_each_entry_safe(src_page, tmp, compound_pagelist, lru) { + list_del(&src_page->lru); + release_pte_page(src_page); + } } static void khugepaged_alloc_sleep(void) @@ -848,8 +933,8 @@ khugepaged_alloc_page(struct page **hpage, gfp_t gfp, int node) #endif /* - * If mmap_sem temporarily dropped, revalidate vma - * before taking mmap_sem. + * If mmap_lock temporarily dropped, revalidate vma + * before taking mmap_lock. * Return 0 if succeeds, otherwise return none-zero * value (scan code). */ @@ -881,7 +966,7 @@ static int hugepage_vma_revalidate(struct mm_struct *mm, unsigned long address, * Only done if khugepaged_scan_pmd believes it is worthwhile. * * Called and returns without pte mapped or spinlocks held, - * but with mmap_sem held to protect against vma changes. + * but with mmap_lock held to protect against vma changes. */ static bool __collapse_huge_page_swapin(struct mm_struct *mm, @@ -899,11 +984,6 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm, .pgoff = linear_page_index(vma, address), }; - /* we only decide to swapin, if there is enough young ptes */ - if (referenced < HPAGE_PMD_NR/2) { - trace_mm_collapse_huge_page_swapin(mm, swapped_in, referenced, 0); - return false; - } vmf.pte = pte_offset_map(pmd, address); for (; vmf.address < address + HPAGE_PMD_NR*PAGE_SIZE; vmf.pte++, vmf.address += PAGE_SIZE) { @@ -913,9 +993,9 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm, swapped_in++; ret = do_swap_page(&vmf); - /* do_swap_page returns VM_FAULT_RETRY with released mmap_sem */ + /* do_swap_page returns VM_FAULT_RETRY with released mmap_lock */ if (ret & VM_FAULT_RETRY) { - down_read(&mm->mmap_sem); + mmap_read_lock(mm); if (hugepage_vma_revalidate(mm, address, &vmf.vma)) { /* vma is no longer available, don't continue to swapin */ trace_mm_collapse_huge_page_swapin(mm, swapped_in, referenced, 0); @@ -936,6 +1016,11 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm, } vmf.pte--; pte_unmap(vmf.pte); + + /* Drain LRU add pagevec to remove extra pin on the swapped in pages */ + if (swapped_in) + lru_add_drain(); + trace_mm_collapse_huge_page_swapin(mm, swapped_in, referenced, 1); return true; } @@ -943,15 +1028,15 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm, static void collapse_huge_page(struct mm_struct *mm, unsigned long address, struct page **hpage, - int node, int referenced) + int node, int referenced, int unmapped) { + LIST_HEAD(compound_pagelist); pmd_t *pmd, _pmd; pte_t *pte; pgtable_t pgtable; struct page *new_page; spinlock_t *pmd_ptl, *pte_ptl; int isolated = 0, result = 0; - struct mem_cgroup *memcg; struct vm_area_struct *vma; struct mmu_notifier_range range; gfp_t gfp; @@ -962,57 +1047,56 @@ static void collapse_huge_page(struct mm_struct *mm, gfp = alloc_hugepage_khugepaged_gfpmask() | __GFP_THISNODE; /* - * Before allocating the hugepage, release the mmap_sem read lock. + * Before allocating the hugepage, release the mmap_lock read lock. * The allocation can take potentially a long time if it involves - * sync compaction, and we do not need to hold the mmap_sem during + * sync compaction, and we do not need to hold the mmap_lock during * that. We will recheck the vma after taking it again in write mode. */ - up_read(&mm->mmap_sem); + mmap_read_unlock(mm); new_page = khugepaged_alloc_page(hpage, gfp, node); if (!new_page) { result = SCAN_ALLOC_HUGE_PAGE_FAIL; goto out_nolock; } - if (unlikely(mem_cgroup_try_charge(new_page, mm, gfp, &memcg, true))) { + if (unlikely(mem_cgroup_charge(new_page, mm, gfp))) { result = SCAN_CGROUP_CHARGE_FAIL; goto out_nolock; } + count_memcg_page_event(new_page, THP_COLLAPSE_ALLOC); - down_read(&mm->mmap_sem); + mmap_read_lock(mm); result = hugepage_vma_revalidate(mm, address, &vma); if (result) { - mem_cgroup_cancel_charge(new_page, memcg, true); - up_read(&mm->mmap_sem); + mmap_read_unlock(mm); goto out_nolock; } pmd = mm_find_pmd(mm, address); if (!pmd) { result = SCAN_PMD_NULL; - mem_cgroup_cancel_charge(new_page, memcg, true); - up_read(&mm->mmap_sem); + mmap_read_unlock(mm); goto out_nolock; } /* - * __collapse_huge_page_swapin always returns with mmap_sem locked. - * If it fails, we release mmap_sem and jump out_nolock. + * __collapse_huge_page_swapin always returns with mmap_lock locked. + * If it fails, we release mmap_lock and jump out_nolock. * Continuing to collapse causes inconsistency. */ - if (!__collapse_huge_page_swapin(mm, vma, address, pmd, referenced)) { - mem_cgroup_cancel_charge(new_page, memcg, true); - up_read(&mm->mmap_sem); + if (unmapped && !__collapse_huge_page_swapin(mm, vma, address, + pmd, referenced)) { + mmap_read_unlock(mm); goto out_nolock; } - up_read(&mm->mmap_sem); + mmap_read_unlock(mm); /* * Prevent all access to pagetables with the exception of * gup_fast later handled by the ptep_clear_flush and the VM * handled by the anon_vma lock + PG_lock. */ - down_write(&mm->mmap_sem); + mmap_write_lock(mm); result = SCAN_ANY_PROCESS; if (!mmget_still_valid(mm)) goto out; @@ -1044,7 +1128,8 @@ static void collapse_huge_page(struct mm_struct *mm, mmu_notifier_invalidate_range_end(&range); spin_lock(pte_ptl); - isolated = __collapse_huge_page_isolate(vma, address, pte); + isolated = __collapse_huge_page_isolate(vma, address, pte, + &compound_pagelist); spin_unlock(pte_ptl); if (unlikely(!isolated)) { @@ -1069,7 +1154,8 @@ static void collapse_huge_page(struct mm_struct *mm, */ anon_vma_unlock_write(vma->anon_vma); - __collapse_huge_page_copy(pte, new_page, vma, address, pte_ptl); + __collapse_huge_page_copy(pte, new_page, vma, address, pte_ptl, + &compound_pagelist); pte_unmap(pte); __SetPageUptodate(new_page); pgtable = pmd_pgtable(_pmd); @@ -1087,8 +1173,6 @@ static void collapse_huge_page(struct mm_struct *mm, spin_lock(pmd_ptl); BUG_ON(!pmd_none(*pmd)); page_add_new_anon_rmap(new_page, vma, address, true); - mem_cgroup_commit_charge(new_page, memcg, false, true); - count_memcg_events(memcg, THP_COLLAPSE_ALLOC, 1); lru_cache_add_active_or_unevictable(new_page, vma); pgtable_trans_huge_deposit(mm, pmd, pgtable); set_pmd_at(mm, address, pmd, _pmd); @@ -1100,12 +1184,13 @@ static void collapse_huge_page(struct mm_struct *mm, khugepaged_pages_collapsed++; result = SCAN_SUCCEED; out_up_write: - up_write(&mm->mmap_sem); + mmap_write_unlock(mm); out_nolock: + if (!IS_ERR_OR_NULL(*hpage)) + mem_cgroup_uncharge(*hpage); trace_mm_collapse_huge_page(mm, isolated, result); return; out: - mem_cgroup_cancel_charge(new_page, memcg, true); goto out_up_write; } @@ -1116,7 +1201,8 @@ static int khugepaged_scan_pmd(struct mm_struct *mm, { pmd_t *pmd; pte_t *pte, *_pte; - int ret = 0, none_or_zero = 0, result = 0, referenced = 0; + int ret = 0, result = 0, referenced = 0; + int none_or_zero = 0, shared = 0; struct page *page = NULL; unsigned long _address; spinlock_t *ptl; @@ -1188,12 +1274,14 @@ static int khugepaged_scan_pmd(struct mm_struct *mm, goto out_unmap; } - /* TODO: teach khugepaged to collapse THP mapped with pte */ - if (PageCompound(page)) { - result = SCAN_PAGE_COMPOUND; + if (page_mapcount(page) > 1 && + ++shared > khugepaged_max_ptes_shared) { + result = SCAN_EXCEED_SHARED_PTE; goto out_unmap; } + page = compound_head(page); + /* * Record which node the original page is from and save this * information to khugepaged_node_load[]. @@ -1220,11 +1308,23 @@ static int khugepaged_scan_pmd(struct mm_struct *mm, } /* - * cannot use mapcount: can't collapse if there's a gup pin. - * The page must only be referenced by the scanned process - * and page swap cache. + * Check if the page has any GUP (or other external) pins. + * + * Here the check is racy it may see totmal_mapcount > refcount + * in some cases. + * For example, one process with one forked child process. + * The parent has the PMD split due to MADV_DONTNEED, then + * the child is trying unmap the whole PMD, but khugepaged + * may be scanning the parent between the child has + * PageDoubleMap flag cleared and dec the mapcount. So + * khugepaged may see total_mapcount > refcount. + * + * But such case is ephemeral we could always retry collapse + * later. However it may report false positive if the page + * has excessive GUP pins (i.e. 512). Anyway the same check + * will be done again later the risk seems low. */ - if (page_count(page) != 1 + PageSwapCache(page)) { + if (!is_refcount_suitable(page)) { result = SCAN_PAGE_COUNT; goto out_unmap; } @@ -1233,22 +1333,21 @@ static int khugepaged_scan_pmd(struct mm_struct *mm, mmu_notifier_test_young(vma->vm_mm, address)) referenced++; } - if (writable) { - if (referenced) { - result = SCAN_SUCCEED; - ret = 1; - } else { - result = SCAN_LACK_REFERENCED_PAGE; - } - } else { + if (!writable) { result = SCAN_PAGE_RO; + } else if (!referenced || (unmapped && referenced < HPAGE_PMD_NR/2)) { + result = SCAN_LACK_REFERENCED_PAGE; + } else { + result = SCAN_SUCCEED; + ret = 1; } out_unmap: pte_unmap_unlock(pte, ptl); if (ret) { node = khugepaged_find_target_node(); - /* collapse_huge_page will return with the mmap_sem released */ - collapse_huge_page(mm, address, hpage, node, referenced); + /* collapse_huge_page will return with the mmap_lock released */ + collapse_huge_page(mm, address, hpage, node, + referenced, unmapped); } out: trace_mm_khugepaged_scan_pmd(mm, page, writable, referenced, @@ -1418,7 +1517,7 @@ static int khugepaged_collapse_pte_mapped_thps(struct mm_slot *mm_slot) if (likely(mm_slot->nr_pte_mapped_thp == 0)) return 0; - if (!down_write_trylock(&mm->mmap_sem)) + if (!mmap_write_trylock(mm)) return -EBUSY; if (unlikely(khugepaged_test_exit(mm))) @@ -1429,7 +1528,7 @@ static int khugepaged_collapse_pte_mapped_thps(struct mm_slot *mm_slot) out: mm_slot->nr_pte_mapped_thp = 0; - up_write(&mm->mmap_sem); + mmap_write_unlock(mm); return 0; } @@ -1444,11 +1543,11 @@ static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff) /* * Check vma->anon_vma to exclude MAP_PRIVATE mappings that * got written to. These VMAs are likely not worth investing - * down_write(mmap_sem) as PMD-mapping is likely to be split + * mmap_write_lock(mm) as PMD-mapping is likely to be split * later. * * Not that vma->anon_vma check is racy: it can be set up after - * the check but before we took mmap_sem by the fault path. + * the check but before we took mmap_lock by the fault path. * But page lock would prevent establishing any new ptes of the * page, so we are safe. * @@ -1468,18 +1567,18 @@ static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff) if (!pmd) continue; /* - * We need exclusive mmap_sem to retract page table. + * We need exclusive mmap_lock to retract page table. * * We use trylock due to lock inversion: we need to acquire - * mmap_sem while holding page lock. Fault path does it in + * mmap_lock while holding page lock. Fault path does it in * reverse order. Trylock is a way to avoid deadlock. */ - if (down_write_trylock(&vma->vm_mm->mmap_sem)) { + if (mmap_write_trylock(vma->vm_mm)) { spinlock_t *ptl = pmd_lock(vma->vm_mm, pmd); /* assume page table is clear */ _pmd = pmdp_collapse_flush(vma, addr, pmd); spin_unlock(ptl); - up_write(&vma->vm_mm->mmap_sem); + mmap_write_unlock(vma->vm_mm); mm_dec_nr_ptes(vma->vm_mm); pte_free(vma->vm_mm, pmd_pgtable(_pmd)); } else { @@ -1515,7 +1614,6 @@ static void collapse_file(struct mm_struct *mm, struct address_space *mapping = file->f_mapping; gfp_t gfp; struct page *new_page; - struct mem_cgroup *memcg; pgoff_t index, end = start + HPAGE_PMD_NR; LIST_HEAD(pagelist); XA_STATE_ORDER(xas, &mapping->i_pages, start, HPAGE_PMD_ORDER); @@ -1534,10 +1632,11 @@ static void collapse_file(struct mm_struct *mm, goto out; } - if (unlikely(mem_cgroup_try_charge(new_page, mm, gfp, &memcg, true))) { + if (unlikely(mem_cgroup_charge(new_page, mm, gfp))) { result = SCAN_CGROUP_CHARGE_FAIL; goto out; } + count_memcg_page_event(new_page, THP_COLLAPSE_ALLOC); /* This will be less messy when we use multi-index entries */ do { @@ -1547,7 +1646,6 @@ static void collapse_file(struct mm_struct *mm, break; xas_unlock_irq(&xas); if (!xas_nomem(&xas, GFP_KERNEL)) { - mem_cgroup_cancel_charge(new_page, memcg, true); result = SCAN_FAIL; goto out; } @@ -1741,12 +1839,9 @@ out_unlock: } if (nr_none) { - struct zone *zone = page_zone(new_page); - - __mod_node_page_state(zone->zone_pgdat, NR_FILE_PAGES, nr_none); + __mod_lruvec_page_state(new_page, NR_FILE_PAGES, nr_none); if (is_shmem) - __mod_node_page_state(zone->zone_pgdat, - NR_SHMEM, nr_none); + __mod_lruvec_page_state(new_page, NR_SHMEM, nr_none); } xa_locked: @@ -1784,15 +1879,9 @@ xa_unlocked: SetPageUptodate(new_page); page_ref_add(new_page, HPAGE_PMD_NR - 1); - mem_cgroup_commit_charge(new_page, memcg, false, true); - - if (is_shmem) { + if (is_shmem) set_page_dirty(new_page); - lru_cache_add_anon(new_page); - } else { - lru_cache_add_file(new_page); - } - count_memcg_events(memcg, THP_COLLAPSE_ALLOC, 1); + lru_cache_add(new_page); /* * Remove pte page tables, so we can re-fault the page as huge. @@ -1839,13 +1928,14 @@ xa_unlocked: VM_BUG_ON(nr_none); xas_unlock_irq(&xas); - mem_cgroup_cancel_charge(new_page, memcg, true); new_page->mapping = NULL; } unlock_page(new_page); out: VM_BUG_ON(!list_empty(&pagelist)); + if (!IS_ERR_OR_NULL(*hpage)) + mem_cgroup_uncharge(*hpage); /* TODO: tracepoints */ } @@ -1967,8 +2057,8 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, * the next mm on the list. */ vma = NULL; - if (unlikely(!down_read_trylock(&mm->mmap_sem))) - goto breakouterloop_mmap_sem; + if (unlikely(!mmap_read_trylock(mm))) + goto breakouterloop_mmap_lock; if (likely(!khugepaged_test_exit(mm))) vma = find_vma(mm, khugepaged_scan.address); @@ -2012,7 +2102,7 @@ skip: pgoff_t pgoff = linear_page_index(vma, khugepaged_scan.address); - up_read(&mm->mmap_sem); + mmap_read_unlock(mm); ret = 1; khugepaged_scan_file(mm, file, pgoff, hpage); fput(file); @@ -2025,15 +2115,15 @@ skip: khugepaged_scan.address += HPAGE_PMD_SIZE; progress += HPAGE_PMD_NR; if (ret) - /* we released mmap_sem so break loop */ - goto breakouterloop_mmap_sem; + /* we released mmap_lock so break loop */ + goto breakouterloop_mmap_lock; if (progress >= pages) goto breakouterloop; } } breakouterloop: - up_read(&mm->mmap_sem); /* exit_mmap will destroy ptes after this */ -breakouterloop_mmap_sem: + mmap_read_unlock(mm); /* exit_mmap will destroy ptes after this */ +breakouterloop_mmap_lock: spin_lock(&khugepaged_mm_lock); VM_BUG_ON(khugepaged_scan.mm_slot != mm_slot); @@ -2084,6 +2174,8 @@ static void khugepaged_do_scan(void) barrier(); /* write khugepaged_pages_to_scan to local stack */ + lru_add_drain_all(); + while (progress < pages) { if (!khugepaged_prealloc_page(&hpage, &wait)) break; |