1b2441318SGreg Kroah-Hartman // SPDX-License-Identifier: GPL-2.0 2b20a3503SChristoph Lameter /* 314e0f9bcSHugh Dickins * Memory Migration functionality - linux/mm/migrate.c 4b20a3503SChristoph Lameter * 5b20a3503SChristoph Lameter * Copyright (C) 2006 Silicon Graphics, Inc., Christoph Lameter 6b20a3503SChristoph Lameter * 7b20a3503SChristoph Lameter * Page migration was first developed in the context of the memory hotplug 8b20a3503SChristoph Lameter * project. The main authors of the migration code are: 9b20a3503SChristoph Lameter * 10b20a3503SChristoph Lameter * IWAMOTO Toshihiro <iwamoto@valinux.co.jp> 11b20a3503SChristoph Lameter * Hirokazu Takahashi <taka@valinux.co.jp> 12b20a3503SChristoph Lameter * Dave Hansen <haveblue@us.ibm.com> 13cde53535SChristoph Lameter * Christoph Lameter 14b20a3503SChristoph Lameter */ 15b20a3503SChristoph Lameter 16b20a3503SChristoph Lameter #include <linux/migrate.h> 17b95f1b31SPaul Gortmaker #include <linux/export.h> 18b20a3503SChristoph Lameter #include <linux/swap.h> 190697212aSChristoph Lameter #include <linux/swapops.h> 20b20a3503SChristoph Lameter #include <linux/pagemap.h> 21e23ca00bSChristoph Lameter #include <linux/buffer_head.h> 22b20a3503SChristoph Lameter #include <linux/mm_inline.h> 23b488893aSPavel Emelyanov #include <linux/nsproxy.h> 24e9995ef9SHugh Dickins #include <linux/ksm.h> 25b20a3503SChristoph Lameter #include <linux/rmap.h> 26b20a3503SChristoph Lameter #include <linux/topology.h> 27b20a3503SChristoph Lameter #include <linux/cpu.h> 28b20a3503SChristoph Lameter #include <linux/cpuset.h> 2904e62a29SChristoph Lameter #include <linux/writeback.h> 30742755a1SChristoph Lameter #include <linux/mempolicy.h> 31742755a1SChristoph Lameter #include <linux/vmalloc.h> 3286c3a764SDavid Quigley #include <linux/security.h> 3342cb14b1SHugh Dickins #include <linux/backing-dev.h> 34bda807d4SMinchan Kim #include <linux/compaction.h> 354f5ca265SAdrian Bunk #include <linux/syscalls.h> 367addf443SDominik Brodowski #include <linux/compat.h> 37290408d4SNaoya Horiguchi #include <linux/hugetlb.h> 388e6ac7faSAneesh Kumar K.V #include <linux/hugetlb_cgroup.h> 395a0e3ad6STejun Heo #include <linux/gfp.h> 40df6ad698SJérôme Glisse #include <linux/pfn_t.h> 41a5430ddaSJérôme Glisse #include <linux/memremap.h> 428315ada7SJérôme Glisse #include <linux/userfaultfd_k.h> 43bf6bddf1SRafael Aquini #include <linux/balloon_compaction.h> 4433c3fc71SVladimir Davydov #include <linux/page_idle.h> 45d435edcaSVlastimil Babka #include <linux/page_owner.h> 466e84f315SIngo Molnar #include <linux/sched/mm.h> 47197e7e52SLinus Torvalds #include <linux/ptrace.h> 4834290e2cSRalph Campbell #include <linux/oom.h> 49884a6e5dSDave Hansen #include <linux/memory.h> 50ac16ec83SBaolin Wang #include <linux/random.h> 51c574bbe9SHuang Ying #include <linux/sched/sysctl.h> 52467b171aSAneesh Kumar K.V #include <linux/memory-tiers.h> 53b20a3503SChristoph Lameter 540d1836c3SMichal Nazarewicz #include <asm/tlbflush.h> 550d1836c3SMichal Nazarewicz 567b2a2d4aSMel Gorman #include <trace/events/migrate.h> 577b2a2d4aSMel Gorman 58b20a3503SChristoph Lameter #include "internal.h" 59b20a3503SChristoph Lameter 60cd775580SBaolin Wang bool isolate_movable_page(struct page *page, isolate_mode_t mode) 61bda807d4SMinchan Kim { 6219979497SVishal Moola (Oracle) struct folio *folio = folio_get_nontail_page(page); 6368f2736aSMatthew Wilcox (Oracle) const struct movable_operations *mops; 64bda807d4SMinchan Kim 65bda807d4SMinchan Kim /* 66bda807d4SMinchan Kim * Avoid burning cycles with pages that are yet under __free_pages(), 67bda807d4SMinchan Kim * or just got freed under us. 68bda807d4SMinchan Kim * 69bda807d4SMinchan Kim * In case we 'win' a race for a movable page being freed under us and 70bda807d4SMinchan Kim * raise its refcount preventing __free_pages() from doing its job 71bda807d4SMinchan Kim * the put_page() at the end of this block will take care of 72bda807d4SMinchan Kim * release this page, thus avoiding a nasty leakage. 73bda807d4SMinchan Kim */ 7419979497SVishal Moola (Oracle) if (!folio) 75bda807d4SMinchan Kim goto out; 76bda807d4SMinchan Kim 7719979497SVishal Moola (Oracle) if (unlikely(folio_test_slab(folio))) 7819979497SVishal Moola (Oracle) goto out_putfolio; 798b881763SVlastimil Babka /* Pairs with smp_wmb() in slab freeing, e.g. SLUB's __free_slab() */ 808b881763SVlastimil Babka smp_rmb(); 81bda807d4SMinchan Kim /* 828b881763SVlastimil Babka * Check movable flag before taking the page lock because 838b881763SVlastimil Babka * we use non-atomic bitops on newly allocated page flags so 848b881763SVlastimil Babka * unconditionally grabbing the lock ruins page's owner side. 85bda807d4SMinchan Kim */ 8619979497SVishal Moola (Oracle) if (unlikely(!__folio_test_movable(folio))) 8719979497SVishal Moola (Oracle) goto out_putfolio; 888b881763SVlastimil Babka /* Pairs with smp_wmb() in slab allocation, e.g. SLUB's alloc_slab_page() */ 898b881763SVlastimil Babka smp_rmb(); 9019979497SVishal Moola (Oracle) if (unlikely(folio_test_slab(folio))) 9119979497SVishal Moola (Oracle) goto out_putfolio; 928b881763SVlastimil Babka 93bda807d4SMinchan Kim /* 94bda807d4SMinchan Kim * As movable pages are not isolated from LRU lists, concurrent 95bda807d4SMinchan Kim * compaction threads can race against page migration functions 96bda807d4SMinchan Kim * as well as race against the releasing a page. 97bda807d4SMinchan Kim * 98bda807d4SMinchan Kim * In order to avoid having an already isolated movable page 99bda807d4SMinchan Kim * being (wrongly) re-isolated while it is under migration, 100bda807d4SMinchan Kim * or to avoid attempting to isolate pages being released, 101bda807d4SMinchan Kim * lets be sure we have the page lock 102bda807d4SMinchan Kim * before proceeding with the movable page isolation steps. 103bda807d4SMinchan Kim */ 10419979497SVishal Moola (Oracle) if (unlikely(!folio_trylock(folio))) 10519979497SVishal Moola (Oracle) goto out_putfolio; 106bda807d4SMinchan Kim 10719979497SVishal Moola (Oracle) if (!folio_test_movable(folio) || folio_test_isolated(folio)) 108bda807d4SMinchan Kim goto out_no_isolated; 109bda807d4SMinchan Kim 11019979497SVishal Moola (Oracle) mops = folio_movable_ops(folio); 11119979497SVishal Moola (Oracle) VM_BUG_ON_FOLIO(!mops, folio); 112bda807d4SMinchan Kim 11319979497SVishal Moola (Oracle) if (!mops->isolate_page(&folio->page, mode)) 114bda807d4SMinchan Kim goto out_no_isolated; 115bda807d4SMinchan Kim 116bda807d4SMinchan Kim /* Driver shouldn't use PG_isolated bit of page->flags */ 11719979497SVishal Moola (Oracle) WARN_ON_ONCE(folio_test_isolated(folio)); 11819979497SVishal Moola (Oracle) folio_set_isolated(folio); 11919979497SVishal Moola (Oracle) folio_unlock(folio); 120bda807d4SMinchan Kim 121cd775580SBaolin Wang return true; 122bda807d4SMinchan Kim 123bda807d4SMinchan Kim out_no_isolated: 12419979497SVishal Moola (Oracle) folio_unlock(folio); 12519979497SVishal Moola (Oracle) out_putfolio: 12619979497SVishal Moola (Oracle) folio_put(folio); 127bda807d4SMinchan Kim out: 128cd775580SBaolin Wang return false; 129bda807d4SMinchan Kim } 130bda807d4SMinchan Kim 131280d724aSVishal Moola (Oracle) static void putback_movable_folio(struct folio *folio) 132bda807d4SMinchan Kim { 133280d724aSVishal Moola (Oracle) const struct movable_operations *mops = folio_movable_ops(folio); 134bda807d4SMinchan Kim 135280d724aSVishal Moola (Oracle) mops->putback_page(&folio->page); 136280d724aSVishal Moola (Oracle) folio_clear_isolated(folio); 137bda807d4SMinchan Kim } 138bda807d4SMinchan Kim 139b20a3503SChristoph Lameter /* 1405733c7d1SRafael Aquini * Put previously isolated pages back onto the appropriate lists 1415733c7d1SRafael Aquini * from where they were once taken off for compaction/migration. 1425733c7d1SRafael Aquini * 14359c82b70SJoonsoo Kim * This function shall be used whenever the isolated pageset has been 14459c82b70SJoonsoo Kim * built from lru, balloon, hugetlbfs page. See isolate_migratepages_range() 1457ce82f4cSMiaohe Lin * and isolate_hugetlb(). 1465733c7d1SRafael Aquini */ 1475733c7d1SRafael Aquini void putback_movable_pages(struct list_head *l) 1485733c7d1SRafael Aquini { 149280d724aSVishal Moola (Oracle) struct folio *folio; 150280d724aSVishal Moola (Oracle) struct folio *folio2; 1515733c7d1SRafael Aquini 152280d724aSVishal Moola (Oracle) list_for_each_entry_safe(folio, folio2, l, lru) { 153280d724aSVishal Moola (Oracle) if (unlikely(folio_test_hugetlb(folio))) { 154280d724aSVishal Moola (Oracle) folio_putback_active_hugetlb(folio); 15531caf665SNaoya Horiguchi continue; 15631caf665SNaoya Horiguchi } 157280d724aSVishal Moola (Oracle) list_del(&folio->lru); 158bda807d4SMinchan Kim /* 159280d724aSVishal Moola (Oracle) * We isolated non-lru movable folio so here we can use 160280d724aSVishal Moola (Oracle) * __PageMovable because LRU folio's mapping cannot have 161bda807d4SMinchan Kim * PAGE_MAPPING_MOVABLE. 162bda807d4SMinchan Kim */ 163280d724aSVishal Moola (Oracle) if (unlikely(__folio_test_movable(folio))) { 164280d724aSVishal Moola (Oracle) VM_BUG_ON_FOLIO(!folio_test_isolated(folio), folio); 165280d724aSVishal Moola (Oracle) folio_lock(folio); 166280d724aSVishal Moola (Oracle) if (folio_test_movable(folio)) 167280d724aSVishal Moola (Oracle) putback_movable_folio(folio); 168bf6bddf1SRafael Aquini else 169280d724aSVishal Moola (Oracle) folio_clear_isolated(folio); 170280d724aSVishal Moola (Oracle) folio_unlock(folio); 171280d724aSVishal Moola (Oracle) folio_put(folio); 172bda807d4SMinchan Kim } else { 173280d724aSVishal Moola (Oracle) node_stat_mod_folio(folio, NR_ISOLATED_ANON + 174280d724aSVishal Moola (Oracle) folio_is_file_lru(folio), -folio_nr_pages(folio)); 175280d724aSVishal Moola (Oracle) folio_putback_lru(folio); 176b20a3503SChristoph Lameter } 177b20a3503SChristoph Lameter } 178bda807d4SMinchan Kim } 179b20a3503SChristoph Lameter 1800697212aSChristoph Lameter /* 1810697212aSChristoph Lameter * Restore a potential migration pte to a working pte entry 1820697212aSChristoph Lameter */ 1832f031c6fSMatthew Wilcox (Oracle) static bool remove_migration_pte(struct folio *folio, 1842f031c6fSMatthew Wilcox (Oracle) struct vm_area_struct *vma, unsigned long addr, void *old) 1850697212aSChristoph Lameter { 1864eecb8b9SMatthew Wilcox (Oracle) DEFINE_FOLIO_VMA_WALK(pvmw, old, vma, addr, PVMW_SYNC | PVMW_MIGRATION); 1870697212aSChristoph Lameter 1883fe87967SKirill A. Shutemov while (page_vma_mapped_walk(&pvmw)) { 1896c287605SDavid Hildenbrand rmap_t rmap_flags = RMAP_NONE; 190c33c7948SRyan Roberts pte_t old_pte; 1910697212aSChristoph Lameter pte_t pte; 1920697212aSChristoph Lameter swp_entry_t entry; 1934eecb8b9SMatthew Wilcox (Oracle) struct page *new; 1944eecb8b9SMatthew Wilcox (Oracle) unsigned long idx = 0; 1950697212aSChristoph Lameter 1964eecb8b9SMatthew Wilcox (Oracle) /* pgoff is invalid for ksm pages, but they are never large */ 1974eecb8b9SMatthew Wilcox (Oracle) if (folio_test_large(folio) && !folio_test_hugetlb(folio)) 1984eecb8b9SMatthew Wilcox (Oracle) idx = linear_page_index(vma, pvmw.address) - pvmw.pgoff; 1994eecb8b9SMatthew Wilcox (Oracle) new = folio_page(folio, idx); 2000697212aSChristoph Lameter 201616b8371SZi Yan #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION 202616b8371SZi Yan /* PMD-mapped THP migration entry */ 203616b8371SZi Yan if (!pvmw.pte) { 2044eecb8b9SMatthew Wilcox (Oracle) VM_BUG_ON_FOLIO(folio_test_hugetlb(folio) || 2054eecb8b9SMatthew Wilcox (Oracle) !folio_test_pmd_mappable(folio), folio); 206616b8371SZi Yan remove_migration_pmd(&pvmw, new); 207616b8371SZi Yan continue; 208616b8371SZi Yan } 209616b8371SZi Yan #endif 210616b8371SZi Yan 2114eecb8b9SMatthew Wilcox (Oracle) folio_get(folio); 2122e346877SPeter Xu pte = mk_pte(new, READ_ONCE(vma->vm_page_prot)); 213c33c7948SRyan Roberts old_pte = ptep_get(pvmw.pte); 214c33c7948SRyan Roberts if (pte_swp_soft_dirty(old_pte)) 215c3d16e16SCyrill Gorcunov pte = pte_mksoft_dirty(pte); 216d3cb8bf6SMel Gorman 217c33c7948SRyan Roberts entry = pte_to_swp_entry(old_pte); 2182e346877SPeter Xu if (!is_migration_entry_young(entry)) 2192e346877SPeter Xu pte = pte_mkold(pte); 2202e346877SPeter Xu if (folio_test_dirty(folio) && is_migration_entry_dirty(entry)) 2212e346877SPeter Xu pte = pte_mkdirty(pte); 2224dd845b5SAlistair Popple if (is_writable_migration_entry(entry)) 223f3ebdf04SDavid Hildenbrand pte = pte_mkwrite(pte); 224c33c7948SRyan Roberts else if (pte_swp_uffd_wp(old_pte)) 225f45ec5ffSPeter Xu pte = pte_mkuffd_wp(pte); 226d3cb8bf6SMel Gorman 2276c287605SDavid Hildenbrand if (folio_test_anon(folio) && !is_readable_migration_entry(entry)) 2286c287605SDavid Hildenbrand rmap_flags |= RMAP_EXCLUSIVE; 2296c287605SDavid Hildenbrand 2306128763fSRalph Campbell if (unlikely(is_device_private_page(new))) { 2314dd845b5SAlistair Popple if (pte_write(pte)) 2324dd845b5SAlistair Popple entry = make_writable_device_private_entry( 2334dd845b5SAlistair Popple page_to_pfn(new)); 2344dd845b5SAlistair Popple else 2354dd845b5SAlistair Popple entry = make_readable_device_private_entry( 2364dd845b5SAlistair Popple page_to_pfn(new)); 237a5430ddaSJérôme Glisse pte = swp_entry_to_pte(entry); 238c33c7948SRyan Roberts if (pte_swp_soft_dirty(old_pte)) 2393d321bf8SRalph Campbell pte = pte_swp_mksoft_dirty(pte); 240c33c7948SRyan Roberts if (pte_swp_uffd_wp(old_pte)) 241ebdf8321SAlistair Popple pte = pte_swp_mkuffd_wp(pte); 242df6ad698SJérôme Glisse } 243a5430ddaSJérôme Glisse 2443ef8fd7fSAndi Kleen #ifdef CONFIG_HUGETLB_PAGE 2454eecb8b9SMatthew Wilcox (Oracle) if (folio_test_hugetlb(folio)) { 24679c1c594SChristophe Leroy unsigned int shift = huge_page_shift(hstate_vma(vma)); 24779c1c594SChristophe Leroy 24879c1c594SChristophe Leroy pte = arch_make_huge_pte(pte, shift, vma->vm_flags); 2494eecb8b9SMatthew Wilcox (Oracle) if (folio_test_anon(folio)) 25028c5209dSDavid Hildenbrand hugepage_add_anon_rmap(new, vma, pvmw.address, 2516c287605SDavid Hildenbrand rmap_flags); 252290408d4SNaoya Horiguchi else 253fb3d824dSDavid Hildenbrand page_dup_file_rmap(new, true); 2541eba86c0SPasha Tatashin set_huge_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte); 255383321abSAneesh Kumar K.V } else 256383321abSAneesh Kumar K.V #endif 257383321abSAneesh Kumar K.V { 2584eecb8b9SMatthew Wilcox (Oracle) if (folio_test_anon(folio)) 259f1e2db12SDavid Hildenbrand page_add_anon_rmap(new, vma, pvmw.address, 2606c287605SDavid Hildenbrand rmap_flags); 26104e62a29SChristoph Lameter else 262cea86fe2SHugh Dickins page_add_file_rmap(new, vma, false); 2631eba86c0SPasha Tatashin set_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte); 264383321abSAneesh Kumar K.V } 265b7435507SHugh Dickins if (vma->vm_flags & VM_LOCKED) 26696f97c43SLorenzo Stoakes mlock_drain_local(); 267e125fe40SKirill A. Shutemov 2684cc79b33SAnshuman Khandual trace_remove_migration_pte(pvmw.address, pte_val(pte), 2694cc79b33SAnshuman Khandual compound_order(new)); 2704cc79b33SAnshuman Khandual 27104e62a29SChristoph Lameter /* No need to invalidate - it was non-present before */ 2723fe87967SKirill A. Shutemov update_mmu_cache(vma, pvmw.address, pvmw.pte); 2733fe87967SKirill A. Shutemov } 2743fe87967SKirill A. Shutemov 275e4b82222SMinchan Kim return true; 2760697212aSChristoph Lameter } 2770697212aSChristoph Lameter 2780697212aSChristoph Lameter /* 27904e62a29SChristoph Lameter * Get rid of all migration entries and replace them by 28004e62a29SChristoph Lameter * references to the indicated page. 28104e62a29SChristoph Lameter */ 2824eecb8b9SMatthew Wilcox (Oracle) void remove_migration_ptes(struct folio *src, struct folio *dst, bool locked) 28304e62a29SChristoph Lameter { 284051ac83aSJoonsoo Kim struct rmap_walk_control rwc = { 285051ac83aSJoonsoo Kim .rmap_one = remove_migration_pte, 2864eecb8b9SMatthew Wilcox (Oracle) .arg = src, 287051ac83aSJoonsoo Kim }; 288051ac83aSJoonsoo Kim 289e388466dSKirill A. Shutemov if (locked) 2902f031c6fSMatthew Wilcox (Oracle) rmap_walk_locked(dst, &rwc); 291e388466dSKirill A. Shutemov else 2922f031c6fSMatthew Wilcox (Oracle) rmap_walk(dst, &rwc); 29304e62a29SChristoph Lameter } 29404e62a29SChristoph Lameter 29504e62a29SChristoph Lameter /* 2960697212aSChristoph Lameter * Something used the pte of a page under migration. We need to 2970697212aSChristoph Lameter * get to the page and wait until migration is finished. 2980697212aSChristoph Lameter * When we return from this function the fault will be retried. 2990697212aSChristoph Lameter */ 3000cb8fd4dSHugh Dickins void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, 3010cb8fd4dSHugh Dickins unsigned long address) 3020697212aSChristoph Lameter { 3030cb8fd4dSHugh Dickins spinlock_t *ptl; 3040cb8fd4dSHugh Dickins pte_t *ptep; 30530dad309SNaoya Horiguchi pte_t pte; 3060697212aSChristoph Lameter swp_entry_t entry; 3070697212aSChristoph Lameter 3080cb8fd4dSHugh Dickins ptep = pte_offset_map_lock(mm, pmd, address, &ptl); 30904dee9e8SHugh Dickins if (!ptep) 31004dee9e8SHugh Dickins return; 31104dee9e8SHugh Dickins 312c33c7948SRyan Roberts pte = ptep_get(ptep); 3130cb8fd4dSHugh Dickins pte_unmap(ptep); 3140cb8fd4dSHugh Dickins 3150697212aSChristoph Lameter if (!is_swap_pte(pte)) 3160697212aSChristoph Lameter goto out; 3170697212aSChristoph Lameter 3180697212aSChristoph Lameter entry = pte_to_swp_entry(pte); 3190697212aSChristoph Lameter if (!is_migration_entry(entry)) 3200697212aSChristoph Lameter goto out; 3210697212aSChristoph Lameter 3220cb8fd4dSHugh Dickins migration_entry_wait_on_locked(entry, ptl); 3230697212aSChristoph Lameter return; 3240697212aSChristoph Lameter out: 3250cb8fd4dSHugh Dickins spin_unlock(ptl); 32630dad309SNaoya Horiguchi } 32730dad309SNaoya Horiguchi 328ad1ac596SMiaohe Lin #ifdef CONFIG_HUGETLB_PAGE 329fcd48540SPeter Xu /* 330fcd48540SPeter Xu * The vma read lock must be held upon entry. Holding that lock prevents either 331fcd48540SPeter Xu * the pte or the ptl from being freed. 332fcd48540SPeter Xu * 333fcd48540SPeter Xu * This function will release the vma lock before returning. 334fcd48540SPeter Xu */ 3350cb8fd4dSHugh Dickins void migration_entry_wait_huge(struct vm_area_struct *vma, pte_t *ptep) 33630dad309SNaoya Horiguchi { 3370cb8fd4dSHugh Dickins spinlock_t *ptl = huge_pte_lockptr(hstate_vma(vma), vma->vm_mm, ptep); 338ad1ac596SMiaohe Lin pte_t pte; 339ad1ac596SMiaohe Lin 340fcd48540SPeter Xu hugetlb_vma_assert_locked(vma); 341ad1ac596SMiaohe Lin spin_lock(ptl); 342ad1ac596SMiaohe Lin pte = huge_ptep_get(ptep); 343ad1ac596SMiaohe Lin 344fcd48540SPeter Xu if (unlikely(!is_hugetlb_entry_migration(pte))) { 345ad1ac596SMiaohe Lin spin_unlock(ptl); 346fcd48540SPeter Xu hugetlb_vma_unlock_read(vma); 347fcd48540SPeter Xu } else { 348fcd48540SPeter Xu /* 349fcd48540SPeter Xu * If migration entry existed, safe to release vma lock 350fcd48540SPeter Xu * here because the pgtable page won't be freed without the 351fcd48540SPeter Xu * pgtable lock released. See comment right above pgtable 352fcd48540SPeter Xu * lock release in migration_entry_wait_on_locked(). 353fcd48540SPeter Xu */ 354fcd48540SPeter Xu hugetlb_vma_unlock_read(vma); 3550cb8fd4dSHugh Dickins migration_entry_wait_on_locked(pte_to_swp_entry(pte), ptl); 35630dad309SNaoya Horiguchi } 357fcd48540SPeter Xu } 358ad1ac596SMiaohe Lin #endif 359ad1ac596SMiaohe Lin 360616b8371SZi Yan #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION 361616b8371SZi Yan void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd) 362616b8371SZi Yan { 363616b8371SZi Yan spinlock_t *ptl; 364616b8371SZi Yan 365616b8371SZi Yan ptl = pmd_lock(mm, pmd); 366616b8371SZi Yan if (!is_pmd_migration_entry(*pmd)) 367616b8371SZi Yan goto unlock; 3680cb8fd4dSHugh Dickins migration_entry_wait_on_locked(pmd_to_swp_entry(*pmd), ptl); 369616b8371SZi Yan return; 370616b8371SZi Yan unlock: 371616b8371SZi Yan spin_unlock(ptl); 372616b8371SZi Yan } 373616b8371SZi Yan #endif 374616b8371SZi Yan 375108ca835SMatthew Wilcox (Oracle) static int folio_expected_refs(struct address_space *mapping, 376108ca835SMatthew Wilcox (Oracle) struct folio *folio) 3770b3901b3SJan Kara { 378108ca835SMatthew Wilcox (Oracle) int refs = 1; 379108ca835SMatthew Wilcox (Oracle) if (!mapping) 380108ca835SMatthew Wilcox (Oracle) return refs; 3810b3901b3SJan Kara 382108ca835SMatthew Wilcox (Oracle) refs += folio_nr_pages(folio); 383108ca835SMatthew Wilcox (Oracle) if (folio_test_private(folio)) 384108ca835SMatthew Wilcox (Oracle) refs++; 385108ca835SMatthew Wilcox (Oracle) 386108ca835SMatthew Wilcox (Oracle) return refs; 3870b3901b3SJan Kara } 3880b3901b3SJan Kara 389b20a3503SChristoph Lameter /* 390c3fcf8a5SChristoph Lameter * Replace the page in the mapping. 3915b5c7120SChristoph Lameter * 3925b5c7120SChristoph Lameter * The number of remaining references must be: 3935b5c7120SChristoph Lameter * 1 for anonymous pages without a mapping 3945b5c7120SChristoph Lameter * 2 for pages with a mapping 395266cf658SDavid Howells * 3 for pages with a mapping and PagePrivate/PagePrivate2 set. 396b20a3503SChristoph Lameter */ 3973417013eSMatthew Wilcox (Oracle) int folio_migrate_mapping(struct address_space *mapping, 3983417013eSMatthew Wilcox (Oracle) struct folio *newfolio, struct folio *folio, int extra_count) 399b20a3503SChristoph Lameter { 4003417013eSMatthew Wilcox (Oracle) XA_STATE(xas, &mapping->i_pages, folio_index(folio)); 40142cb14b1SHugh Dickins struct zone *oldzone, *newzone; 40242cb14b1SHugh Dickins int dirty; 403108ca835SMatthew Wilcox (Oracle) int expected_count = folio_expected_refs(mapping, folio) + extra_count; 4043417013eSMatthew Wilcox (Oracle) long nr = folio_nr_pages(folio); 4058763cb45SJérôme Glisse 4066c5240aeSChristoph Lameter if (!mapping) { 4070e8c7d0fSChristoph Lameter /* Anonymous page without mapping */ 4083417013eSMatthew Wilcox (Oracle) if (folio_ref_count(folio) != expected_count) 4096c5240aeSChristoph Lameter return -EAGAIN; 410cf4b769aSHugh Dickins 411cf4b769aSHugh Dickins /* No turning back from here */ 4123417013eSMatthew Wilcox (Oracle) newfolio->index = folio->index; 4133417013eSMatthew Wilcox (Oracle) newfolio->mapping = folio->mapping; 4143417013eSMatthew Wilcox (Oracle) if (folio_test_swapbacked(folio)) 4153417013eSMatthew Wilcox (Oracle) __folio_set_swapbacked(newfolio); 416cf4b769aSHugh Dickins 41778bd5209SRafael Aquini return MIGRATEPAGE_SUCCESS; 4186c5240aeSChristoph Lameter } 4196c5240aeSChristoph Lameter 4203417013eSMatthew Wilcox (Oracle) oldzone = folio_zone(folio); 4213417013eSMatthew Wilcox (Oracle) newzone = folio_zone(newfolio); 42242cb14b1SHugh Dickins 42389eb946aSMatthew Wilcox xas_lock_irq(&xas); 4243417013eSMatthew Wilcox (Oracle) if (!folio_ref_freeze(folio, expected_count)) { 42589eb946aSMatthew Wilcox xas_unlock_irq(&xas); 426e286781dSNick Piggin return -EAGAIN; 427e286781dSNick Piggin } 428e286781dSNick Piggin 429b20a3503SChristoph Lameter /* 4303417013eSMatthew Wilcox (Oracle) * Now we know that no one else is looking at the folio: 431cf4b769aSHugh Dickins * no turning back from here. 432b20a3503SChristoph Lameter */ 4333417013eSMatthew Wilcox (Oracle) newfolio->index = folio->index; 4343417013eSMatthew Wilcox (Oracle) newfolio->mapping = folio->mapping; 4353417013eSMatthew Wilcox (Oracle) folio_ref_add(newfolio, nr); /* add cache reference */ 4363417013eSMatthew Wilcox (Oracle) if (folio_test_swapbacked(folio)) { 4373417013eSMatthew Wilcox (Oracle) __folio_set_swapbacked(newfolio); 4383417013eSMatthew Wilcox (Oracle) if (folio_test_swapcache(folio)) { 4393417013eSMatthew Wilcox (Oracle) folio_set_swapcache(newfolio); 4403417013eSMatthew Wilcox (Oracle) newfolio->private = folio_get_private(folio); 441b20a3503SChristoph Lameter } 4426326fec1SNicholas Piggin } else { 4433417013eSMatthew Wilcox (Oracle) VM_BUG_ON_FOLIO(folio_test_swapcache(folio), folio); 4446326fec1SNicholas Piggin } 445b20a3503SChristoph Lameter 44642cb14b1SHugh Dickins /* Move dirty while page refs frozen and newpage not yet exposed */ 4473417013eSMatthew Wilcox (Oracle) dirty = folio_test_dirty(folio); 44842cb14b1SHugh Dickins if (dirty) { 4493417013eSMatthew Wilcox (Oracle) folio_clear_dirty(folio); 4503417013eSMatthew Wilcox (Oracle) folio_set_dirty(newfolio); 45142cb14b1SHugh Dickins } 45242cb14b1SHugh Dickins 4533417013eSMatthew Wilcox (Oracle) xas_store(&xas, newfolio); 4547cf9c2c7SNick Piggin 4557cf9c2c7SNick Piggin /* 456937a94c9SJacobo Giralt * Drop cache reference from old page by unfreezing 457937a94c9SJacobo Giralt * to one less reference. 4587cf9c2c7SNick Piggin * We know this isn't the last reference. 4597cf9c2c7SNick Piggin */ 4603417013eSMatthew Wilcox (Oracle) folio_ref_unfreeze(folio, expected_count - nr); 4617cf9c2c7SNick Piggin 46289eb946aSMatthew Wilcox xas_unlock(&xas); 46342cb14b1SHugh Dickins /* Leave irq disabled to prevent preemption while updating stats */ 46442cb14b1SHugh Dickins 4650e8c7d0fSChristoph Lameter /* 4660e8c7d0fSChristoph Lameter * If moved to a different zone then also account 4670e8c7d0fSChristoph Lameter * the page for that zone. Other VM counters will be 4680e8c7d0fSChristoph Lameter * taken care of when we establish references to the 4690e8c7d0fSChristoph Lameter * new page and drop references to the old page. 4700e8c7d0fSChristoph Lameter * 4710e8c7d0fSChristoph Lameter * Note that anonymous pages are accounted for 4724b9d0fabSMel Gorman * via NR_FILE_PAGES and NR_ANON_MAPPED if they 4730e8c7d0fSChristoph Lameter * are mapped to swap space. 4740e8c7d0fSChristoph Lameter */ 47542cb14b1SHugh Dickins if (newzone != oldzone) { 4760d1c2072SJohannes Weiner struct lruvec *old_lruvec, *new_lruvec; 4770d1c2072SJohannes Weiner struct mem_cgroup *memcg; 4780d1c2072SJohannes Weiner 4793417013eSMatthew Wilcox (Oracle) memcg = folio_memcg(folio); 4800d1c2072SJohannes Weiner old_lruvec = mem_cgroup_lruvec(memcg, oldzone->zone_pgdat); 4810d1c2072SJohannes Weiner new_lruvec = mem_cgroup_lruvec(memcg, newzone->zone_pgdat); 4820d1c2072SJohannes Weiner 4835c447d27SShakeel Butt __mod_lruvec_state(old_lruvec, NR_FILE_PAGES, -nr); 4845c447d27SShakeel Butt __mod_lruvec_state(new_lruvec, NR_FILE_PAGES, nr); 4853417013eSMatthew Wilcox (Oracle) if (folio_test_swapbacked(folio) && !folio_test_swapcache(folio)) { 4865c447d27SShakeel Butt __mod_lruvec_state(old_lruvec, NR_SHMEM, -nr); 4875c447d27SShakeel Butt __mod_lruvec_state(new_lruvec, NR_SHMEM, nr); 4880b52c420SJan Glauber 4890b52c420SJan Glauber if (folio_test_pmd_mappable(folio)) { 4900b52c420SJan Glauber __mod_lruvec_state(old_lruvec, NR_SHMEM_THPS, -nr); 4910b52c420SJan Glauber __mod_lruvec_state(new_lruvec, NR_SHMEM_THPS, nr); 4920b52c420SJan Glauber } 4934b02108aSKOSAKI Motohiro } 494b6038942SShakeel Butt #ifdef CONFIG_SWAP 4953417013eSMatthew Wilcox (Oracle) if (folio_test_swapcache(folio)) { 496b6038942SShakeel Butt __mod_lruvec_state(old_lruvec, NR_SWAPCACHE, -nr); 497b6038942SShakeel Butt __mod_lruvec_state(new_lruvec, NR_SWAPCACHE, nr); 498b6038942SShakeel Butt } 499b6038942SShakeel Butt #endif 500f56753acSChristoph Hellwig if (dirty && mapping_can_writeback(mapping)) { 5015c447d27SShakeel Butt __mod_lruvec_state(old_lruvec, NR_FILE_DIRTY, -nr); 5025c447d27SShakeel Butt __mod_zone_page_state(oldzone, NR_ZONE_WRITE_PENDING, -nr); 5035c447d27SShakeel Butt __mod_lruvec_state(new_lruvec, NR_FILE_DIRTY, nr); 5045c447d27SShakeel Butt __mod_zone_page_state(newzone, NR_ZONE_WRITE_PENDING, nr); 50542cb14b1SHugh Dickins } 50642cb14b1SHugh Dickins } 50742cb14b1SHugh Dickins local_irq_enable(); 508b20a3503SChristoph Lameter 50978bd5209SRafael Aquini return MIGRATEPAGE_SUCCESS; 510b20a3503SChristoph Lameter } 5113417013eSMatthew Wilcox (Oracle) EXPORT_SYMBOL(folio_migrate_mapping); 512b20a3503SChristoph Lameter 513b20a3503SChristoph Lameter /* 514290408d4SNaoya Horiguchi * The expected number of remaining references is the same as that 5153417013eSMatthew Wilcox (Oracle) * of folio_migrate_mapping(). 516290408d4SNaoya Horiguchi */ 517290408d4SNaoya Horiguchi int migrate_huge_page_move_mapping(struct address_space *mapping, 518b890ec2aSMatthew Wilcox (Oracle) struct folio *dst, struct folio *src) 519290408d4SNaoya Horiguchi { 520b890ec2aSMatthew Wilcox (Oracle) XA_STATE(xas, &mapping->i_pages, folio_index(src)); 521290408d4SNaoya Horiguchi int expected_count; 522290408d4SNaoya Horiguchi 52389eb946aSMatthew Wilcox xas_lock_irq(&xas); 524b890ec2aSMatthew Wilcox (Oracle) expected_count = 2 + folio_has_private(src); 525b890ec2aSMatthew Wilcox (Oracle) if (!folio_ref_freeze(src, expected_count)) { 52689eb946aSMatthew Wilcox xas_unlock_irq(&xas); 527290408d4SNaoya Horiguchi return -EAGAIN; 528290408d4SNaoya Horiguchi } 529290408d4SNaoya Horiguchi 530b890ec2aSMatthew Wilcox (Oracle) dst->index = src->index; 531b890ec2aSMatthew Wilcox (Oracle) dst->mapping = src->mapping; 5326a93ca8fSJohannes Weiner 533b890ec2aSMatthew Wilcox (Oracle) folio_get(dst); 534290408d4SNaoya Horiguchi 535b890ec2aSMatthew Wilcox (Oracle) xas_store(&xas, dst); 536290408d4SNaoya Horiguchi 537b890ec2aSMatthew Wilcox (Oracle) folio_ref_unfreeze(src, expected_count - 1); 538290408d4SNaoya Horiguchi 53989eb946aSMatthew Wilcox xas_unlock_irq(&xas); 5406a93ca8fSJohannes Weiner 54178bd5209SRafael Aquini return MIGRATEPAGE_SUCCESS; 542290408d4SNaoya Horiguchi } 543290408d4SNaoya Horiguchi 544290408d4SNaoya Horiguchi /* 54519138349SMatthew Wilcox (Oracle) * Copy the flags and some other ancillary information 546b20a3503SChristoph Lameter */ 54719138349SMatthew Wilcox (Oracle) void folio_migrate_flags(struct folio *newfolio, struct folio *folio) 548b20a3503SChristoph Lameter { 5497851a45cSRik van Riel int cpupid; 5507851a45cSRik van Riel 55119138349SMatthew Wilcox (Oracle) if (folio_test_error(folio)) 55219138349SMatthew Wilcox (Oracle) folio_set_error(newfolio); 55319138349SMatthew Wilcox (Oracle) if (folio_test_referenced(folio)) 55419138349SMatthew Wilcox (Oracle) folio_set_referenced(newfolio); 55519138349SMatthew Wilcox (Oracle) if (folio_test_uptodate(folio)) 55619138349SMatthew Wilcox (Oracle) folio_mark_uptodate(newfolio); 55719138349SMatthew Wilcox (Oracle) if (folio_test_clear_active(folio)) { 55819138349SMatthew Wilcox (Oracle) VM_BUG_ON_FOLIO(folio_test_unevictable(folio), folio); 55919138349SMatthew Wilcox (Oracle) folio_set_active(newfolio); 56019138349SMatthew Wilcox (Oracle) } else if (folio_test_clear_unevictable(folio)) 56119138349SMatthew Wilcox (Oracle) folio_set_unevictable(newfolio); 56219138349SMatthew Wilcox (Oracle) if (folio_test_workingset(folio)) 56319138349SMatthew Wilcox (Oracle) folio_set_workingset(newfolio); 56419138349SMatthew Wilcox (Oracle) if (folio_test_checked(folio)) 56519138349SMatthew Wilcox (Oracle) folio_set_checked(newfolio); 5666c287605SDavid Hildenbrand /* 5676c287605SDavid Hildenbrand * PG_anon_exclusive (-> PG_mappedtodisk) is always migrated via 5686c287605SDavid Hildenbrand * migration entries. We can still have PG_anon_exclusive set on an 5696c287605SDavid Hildenbrand * effectively unmapped and unreferenced first sub-pages of an 5706c287605SDavid Hildenbrand * anonymous THP: we can simply copy it here via PG_mappedtodisk. 5716c287605SDavid Hildenbrand */ 57219138349SMatthew Wilcox (Oracle) if (folio_test_mappedtodisk(folio)) 57319138349SMatthew Wilcox (Oracle) folio_set_mappedtodisk(newfolio); 574b20a3503SChristoph Lameter 5753417013eSMatthew Wilcox (Oracle) /* Move dirty on pages not done by folio_migrate_mapping() */ 57619138349SMatthew Wilcox (Oracle) if (folio_test_dirty(folio)) 57719138349SMatthew Wilcox (Oracle) folio_set_dirty(newfolio); 578b20a3503SChristoph Lameter 57919138349SMatthew Wilcox (Oracle) if (folio_test_young(folio)) 58019138349SMatthew Wilcox (Oracle) folio_set_young(newfolio); 58119138349SMatthew Wilcox (Oracle) if (folio_test_idle(folio)) 58219138349SMatthew Wilcox (Oracle) folio_set_idle(newfolio); 58333c3fc71SVladimir Davydov 5847851a45cSRik van Riel /* 5857851a45cSRik van Riel * Copy NUMA information to the new page, to prevent over-eager 5867851a45cSRik van Riel * future migrations of this same page. 5877851a45cSRik van Riel */ 58819138349SMatthew Wilcox (Oracle) cpupid = page_cpupid_xchg_last(&folio->page, -1); 58933024536SHuang Ying /* 59033024536SHuang Ying * For memory tiering mode, when migrate between slow and fast 59133024536SHuang Ying * memory node, reset cpupid, because that is used to record 59233024536SHuang Ying * page access time in slow memory node. 59333024536SHuang Ying */ 59433024536SHuang Ying if (sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING) { 59533024536SHuang Ying bool f_toptier = node_is_toptier(page_to_nid(&folio->page)); 59633024536SHuang Ying bool t_toptier = node_is_toptier(page_to_nid(&newfolio->page)); 59733024536SHuang Ying 59833024536SHuang Ying if (f_toptier != t_toptier) 59933024536SHuang Ying cpupid = -1; 60033024536SHuang Ying } 60119138349SMatthew Wilcox (Oracle) page_cpupid_xchg_last(&newfolio->page, cpupid); 6027851a45cSRik van Riel 60319138349SMatthew Wilcox (Oracle) folio_migrate_ksm(newfolio, folio); 604c8d6553bSHugh Dickins /* 605c8d6553bSHugh Dickins * Please do not reorder this without considering how mm/ksm.c's 606c8d6553bSHugh Dickins * get_ksm_page() depends upon ksm_migrate_page() and PageSwapCache(). 607c8d6553bSHugh Dickins */ 60819138349SMatthew Wilcox (Oracle) if (folio_test_swapcache(folio)) 60919138349SMatthew Wilcox (Oracle) folio_clear_swapcache(folio); 61019138349SMatthew Wilcox (Oracle) folio_clear_private(folio); 611ad2fa371SMuchun Song 612ad2fa371SMuchun Song /* page->private contains hugetlb specific flags */ 61319138349SMatthew Wilcox (Oracle) if (!folio_test_hugetlb(folio)) 61419138349SMatthew Wilcox (Oracle) folio->private = NULL; 615b20a3503SChristoph Lameter 616b20a3503SChristoph Lameter /* 617b20a3503SChristoph Lameter * If any waiters have accumulated on the new page then 618b20a3503SChristoph Lameter * wake them up. 619b20a3503SChristoph Lameter */ 62019138349SMatthew Wilcox (Oracle) if (folio_test_writeback(newfolio)) 62119138349SMatthew Wilcox (Oracle) folio_end_writeback(newfolio); 622d435edcaSVlastimil Babka 6236aeff241SYang Shi /* 6246aeff241SYang Shi * PG_readahead shares the same bit with PG_reclaim. The above 6256aeff241SYang Shi * end_page_writeback() may clear PG_readahead mistakenly, so set the 6266aeff241SYang Shi * bit after that. 6276aeff241SYang Shi */ 62819138349SMatthew Wilcox (Oracle) if (folio_test_readahead(folio)) 62919138349SMatthew Wilcox (Oracle) folio_set_readahead(newfolio); 6306aeff241SYang Shi 63119138349SMatthew Wilcox (Oracle) folio_copy_owner(newfolio, folio); 63274485cf2SJohannes Weiner 63319138349SMatthew Wilcox (Oracle) if (!folio_test_hugetlb(folio)) 634d21bba2bSMatthew Wilcox (Oracle) mem_cgroup_migrate(folio, newfolio); 635b20a3503SChristoph Lameter } 63619138349SMatthew Wilcox (Oracle) EXPORT_SYMBOL(folio_migrate_flags); 6372916ecc0SJérôme Glisse 638715cbfd6SMatthew Wilcox (Oracle) void folio_migrate_copy(struct folio *newfolio, struct folio *folio) 6392916ecc0SJérôme Glisse { 640715cbfd6SMatthew Wilcox (Oracle) folio_copy(newfolio, folio); 641715cbfd6SMatthew Wilcox (Oracle) folio_migrate_flags(newfolio, folio); 6422916ecc0SJérôme Glisse } 643715cbfd6SMatthew Wilcox (Oracle) EXPORT_SYMBOL(folio_migrate_copy); 644b20a3503SChristoph Lameter 6451d8b85ccSChristoph Lameter /************************************************************ 6461d8b85ccSChristoph Lameter * Migration functions 6471d8b85ccSChristoph Lameter ***********************************************************/ 6481d8b85ccSChristoph Lameter 64916ce101dSAlistair Popple int migrate_folio_extra(struct address_space *mapping, struct folio *dst, 65016ce101dSAlistair Popple struct folio *src, enum migrate_mode mode, int extra_count) 65116ce101dSAlistair Popple { 65216ce101dSAlistair Popple int rc; 65316ce101dSAlistair Popple 65416ce101dSAlistair Popple BUG_ON(folio_test_writeback(src)); /* Writeback must be complete */ 65516ce101dSAlistair Popple 65616ce101dSAlistair Popple rc = folio_migrate_mapping(mapping, dst, src, extra_count); 65716ce101dSAlistair Popple 65816ce101dSAlistair Popple if (rc != MIGRATEPAGE_SUCCESS) 65916ce101dSAlistair Popple return rc; 66016ce101dSAlistair Popple 66116ce101dSAlistair Popple if (mode != MIGRATE_SYNC_NO_COPY) 66216ce101dSAlistair Popple folio_migrate_copy(dst, src); 66316ce101dSAlistair Popple else 66416ce101dSAlistair Popple folio_migrate_flags(dst, src); 66516ce101dSAlistair Popple return MIGRATEPAGE_SUCCESS; 66616ce101dSAlistair Popple } 66716ce101dSAlistair Popple 66854184650SMatthew Wilcox (Oracle) /** 66954184650SMatthew Wilcox (Oracle) * migrate_folio() - Simple folio migration. 67054184650SMatthew Wilcox (Oracle) * @mapping: The address_space containing the folio. 67154184650SMatthew Wilcox (Oracle) * @dst: The folio to migrate the data to. 67254184650SMatthew Wilcox (Oracle) * @src: The folio containing the current data. 67354184650SMatthew Wilcox (Oracle) * @mode: How to migrate the page. 674b20a3503SChristoph Lameter * 67554184650SMatthew Wilcox (Oracle) * Common logic to directly migrate a single LRU folio suitable for 67654184650SMatthew Wilcox (Oracle) * folios that do not use PagePrivate/PagePrivate2. 67754184650SMatthew Wilcox (Oracle) * 67854184650SMatthew Wilcox (Oracle) * Folios are locked upon entry and exit. 679b20a3503SChristoph Lameter */ 68054184650SMatthew Wilcox (Oracle) int migrate_folio(struct address_space *mapping, struct folio *dst, 68154184650SMatthew Wilcox (Oracle) struct folio *src, enum migrate_mode mode) 682b20a3503SChristoph Lameter { 68316ce101dSAlistair Popple return migrate_folio_extra(mapping, dst, src, mode, 0); 684b20a3503SChristoph Lameter } 68554184650SMatthew Wilcox (Oracle) EXPORT_SYMBOL(migrate_folio); 686b20a3503SChristoph Lameter 687*925c86a1SChristoph Hellwig #ifdef CONFIG_BUFFER_HEAD 68884ade7c1SJan Kara /* Returns true if all buffers are successfully locked */ 68984ade7c1SJan Kara static bool buffer_migrate_lock_buffers(struct buffer_head *head, 69084ade7c1SJan Kara enum migrate_mode mode) 69184ade7c1SJan Kara { 69284ade7c1SJan Kara struct buffer_head *bh = head; 6934bb6dc79SDouglas Anderson struct buffer_head *failed_bh; 69484ade7c1SJan Kara 69584ade7c1SJan Kara do { 6964bb6dc79SDouglas Anderson if (!trylock_buffer(bh)) { 6974bb6dc79SDouglas Anderson if (mode == MIGRATE_ASYNC) 6984bb6dc79SDouglas Anderson goto unlock; 6994bb6dc79SDouglas Anderson if (mode == MIGRATE_SYNC_LIGHT && !buffer_uptodate(bh)) 7004bb6dc79SDouglas Anderson goto unlock; 70184ade7c1SJan Kara lock_buffer(bh); 7024bb6dc79SDouglas Anderson } 70384ade7c1SJan Kara 7044bb6dc79SDouglas Anderson bh = bh->b_this_page; 70584ade7c1SJan Kara } while (bh != head); 70684ade7c1SJan Kara 70784ade7c1SJan Kara return true; 70884ade7c1SJan Kara 7094bb6dc79SDouglas Anderson unlock: 7104bb6dc79SDouglas Anderson /* We failed to lock the buffer and cannot stall. */ 7114bb6dc79SDouglas Anderson failed_bh = bh; 71284ade7c1SJan Kara bh = head; 71384ade7c1SJan Kara while (bh != failed_bh) { 71484ade7c1SJan Kara unlock_buffer(bh); 71584ade7c1SJan Kara bh = bh->b_this_page; 71684ade7c1SJan Kara } 71784ade7c1SJan Kara 7184bb6dc79SDouglas Anderson return false; 71984ade7c1SJan Kara } 72084ade7c1SJan Kara 72167235182SMatthew Wilcox (Oracle) static int __buffer_migrate_folio(struct address_space *mapping, 72267235182SMatthew Wilcox (Oracle) struct folio *dst, struct folio *src, enum migrate_mode mode, 72389cb0888SJan Kara bool check_refs) 7241d8b85ccSChristoph Lameter { 7251d8b85ccSChristoph Lameter struct buffer_head *bh, *head; 7261d8b85ccSChristoph Lameter int rc; 727cc4f11e6SJan Kara int expected_count; 7281d8b85ccSChristoph Lameter 72967235182SMatthew Wilcox (Oracle) head = folio_buffers(src); 73067235182SMatthew Wilcox (Oracle) if (!head) 73154184650SMatthew Wilcox (Oracle) return migrate_folio(mapping, dst, src, mode); 7321d8b85ccSChristoph Lameter 733cc4f11e6SJan Kara /* Check whether page does not have extra refs before we do more work */ 734108ca835SMatthew Wilcox (Oracle) expected_count = folio_expected_refs(mapping, src); 73567235182SMatthew Wilcox (Oracle) if (folio_ref_count(src) != expected_count) 736cc4f11e6SJan Kara return -EAGAIN; 737cc4f11e6SJan Kara 738cc4f11e6SJan Kara if (!buffer_migrate_lock_buffers(head, mode)) 739cc4f11e6SJan Kara return -EAGAIN; 7401d8b85ccSChristoph Lameter 74189cb0888SJan Kara if (check_refs) { 74289cb0888SJan Kara bool busy; 74389cb0888SJan Kara bool invalidated = false; 74489cb0888SJan Kara 74589cb0888SJan Kara recheck_buffers: 74689cb0888SJan Kara busy = false; 74789cb0888SJan Kara spin_lock(&mapping->private_lock); 74889cb0888SJan Kara bh = head; 74989cb0888SJan Kara do { 75089cb0888SJan Kara if (atomic_read(&bh->b_count)) { 75189cb0888SJan Kara busy = true; 75289cb0888SJan Kara break; 75389cb0888SJan Kara } 75489cb0888SJan Kara bh = bh->b_this_page; 75589cb0888SJan Kara } while (bh != head); 75689cb0888SJan Kara if (busy) { 75789cb0888SJan Kara if (invalidated) { 75889cb0888SJan Kara rc = -EAGAIN; 75989cb0888SJan Kara goto unlock_buffers; 76089cb0888SJan Kara } 761ebdf4de5SJan Kara spin_unlock(&mapping->private_lock); 76289cb0888SJan Kara invalidate_bh_lrus(); 76389cb0888SJan Kara invalidated = true; 76489cb0888SJan Kara goto recheck_buffers; 76589cb0888SJan Kara } 76689cb0888SJan Kara } 76789cb0888SJan Kara 76867235182SMatthew Wilcox (Oracle) rc = folio_migrate_mapping(mapping, dst, src, 0); 76978bd5209SRafael Aquini if (rc != MIGRATEPAGE_SUCCESS) 770cc4f11e6SJan Kara goto unlock_buffers; 7711d8b85ccSChristoph Lameter 77267235182SMatthew Wilcox (Oracle) folio_attach_private(dst, folio_detach_private(src)); 7731d8b85ccSChristoph Lameter 7741d8b85ccSChristoph Lameter bh = head; 7751d8b85ccSChristoph Lameter do { 77667235182SMatthew Wilcox (Oracle) set_bh_page(bh, &dst->page, bh_offset(bh)); 7771d8b85ccSChristoph Lameter bh = bh->b_this_page; 7781d8b85ccSChristoph Lameter } while (bh != head); 7791d8b85ccSChristoph Lameter 7802916ecc0SJérôme Glisse if (mode != MIGRATE_SYNC_NO_COPY) 78167235182SMatthew Wilcox (Oracle) folio_migrate_copy(dst, src); 7822916ecc0SJérôme Glisse else 78367235182SMatthew Wilcox (Oracle) folio_migrate_flags(dst, src); 7841d8b85ccSChristoph Lameter 785cc4f11e6SJan Kara rc = MIGRATEPAGE_SUCCESS; 786cc4f11e6SJan Kara unlock_buffers: 787ebdf4de5SJan Kara if (check_refs) 788ebdf4de5SJan Kara spin_unlock(&mapping->private_lock); 7891d8b85ccSChristoph Lameter bh = head; 7901d8b85ccSChristoph Lameter do { 7911d8b85ccSChristoph Lameter unlock_buffer(bh); 7921d8b85ccSChristoph Lameter bh = bh->b_this_page; 7931d8b85ccSChristoph Lameter } while (bh != head); 7941d8b85ccSChristoph Lameter 795cc4f11e6SJan Kara return rc; 7961d8b85ccSChristoph Lameter } 79789cb0888SJan Kara 79867235182SMatthew Wilcox (Oracle) /** 79967235182SMatthew Wilcox (Oracle) * buffer_migrate_folio() - Migration function for folios with buffers. 80067235182SMatthew Wilcox (Oracle) * @mapping: The address space containing @src. 80167235182SMatthew Wilcox (Oracle) * @dst: The folio to migrate to. 80267235182SMatthew Wilcox (Oracle) * @src: The folio to migrate from. 80367235182SMatthew Wilcox (Oracle) * @mode: How to migrate the folio. 80467235182SMatthew Wilcox (Oracle) * 80567235182SMatthew Wilcox (Oracle) * This function can only be used if the underlying filesystem guarantees 80667235182SMatthew Wilcox (Oracle) * that no other references to @src exist. For example attached buffer 80767235182SMatthew Wilcox (Oracle) * heads are accessed only under the folio lock. If your filesystem cannot 80867235182SMatthew Wilcox (Oracle) * provide this guarantee, buffer_migrate_folio_norefs() may be more 80967235182SMatthew Wilcox (Oracle) * appropriate. 81067235182SMatthew Wilcox (Oracle) * 81167235182SMatthew Wilcox (Oracle) * Return: 0 on success or a negative errno on failure. 81289cb0888SJan Kara */ 81367235182SMatthew Wilcox (Oracle) int buffer_migrate_folio(struct address_space *mapping, 81467235182SMatthew Wilcox (Oracle) struct folio *dst, struct folio *src, enum migrate_mode mode) 81589cb0888SJan Kara { 81667235182SMatthew Wilcox (Oracle) return __buffer_migrate_folio(mapping, dst, src, mode, false); 81789cb0888SJan Kara } 81867235182SMatthew Wilcox (Oracle) EXPORT_SYMBOL(buffer_migrate_folio); 81989cb0888SJan Kara 82067235182SMatthew Wilcox (Oracle) /** 82167235182SMatthew Wilcox (Oracle) * buffer_migrate_folio_norefs() - Migration function for folios with buffers. 82267235182SMatthew Wilcox (Oracle) * @mapping: The address space containing @src. 82367235182SMatthew Wilcox (Oracle) * @dst: The folio to migrate to. 82467235182SMatthew Wilcox (Oracle) * @src: The folio to migrate from. 82567235182SMatthew Wilcox (Oracle) * @mode: How to migrate the folio. 82667235182SMatthew Wilcox (Oracle) * 82767235182SMatthew Wilcox (Oracle) * Like buffer_migrate_folio() except that this variant is more careful 82867235182SMatthew Wilcox (Oracle) * and checks that there are also no buffer head references. This function 82967235182SMatthew Wilcox (Oracle) * is the right one for mappings where buffer heads are directly looked 83067235182SMatthew Wilcox (Oracle) * up and referenced (such as block device mappings). 83167235182SMatthew Wilcox (Oracle) * 83267235182SMatthew Wilcox (Oracle) * Return: 0 on success or a negative errno on failure. 83389cb0888SJan Kara */ 83467235182SMatthew Wilcox (Oracle) int buffer_migrate_folio_norefs(struct address_space *mapping, 83567235182SMatthew Wilcox (Oracle) struct folio *dst, struct folio *src, enum migrate_mode mode) 83689cb0888SJan Kara { 83767235182SMatthew Wilcox (Oracle) return __buffer_migrate_folio(mapping, dst, src, mode, true); 83889cb0888SJan Kara } 839e26355e2SJan Kara EXPORT_SYMBOL_GPL(buffer_migrate_folio_norefs); 840*925c86a1SChristoph Hellwig #endif /* CONFIG_BUFFER_HEAD */ 8411d8b85ccSChristoph Lameter 8422ec810d5SMatthew Wilcox (Oracle) int filemap_migrate_folio(struct address_space *mapping, 8432ec810d5SMatthew Wilcox (Oracle) struct folio *dst, struct folio *src, enum migrate_mode mode) 8442ec810d5SMatthew Wilcox (Oracle) { 8452ec810d5SMatthew Wilcox (Oracle) int ret; 8462ec810d5SMatthew Wilcox (Oracle) 8472ec810d5SMatthew Wilcox (Oracle) ret = folio_migrate_mapping(mapping, dst, src, 0); 8482ec810d5SMatthew Wilcox (Oracle) if (ret != MIGRATEPAGE_SUCCESS) 8492ec810d5SMatthew Wilcox (Oracle) return ret; 8502ec810d5SMatthew Wilcox (Oracle) 8512ec810d5SMatthew Wilcox (Oracle) if (folio_get_private(src)) 8522ec810d5SMatthew Wilcox (Oracle) folio_attach_private(dst, folio_detach_private(src)); 8532ec810d5SMatthew Wilcox (Oracle) 8542ec810d5SMatthew Wilcox (Oracle) if (mode != MIGRATE_SYNC_NO_COPY) 8552ec810d5SMatthew Wilcox (Oracle) folio_migrate_copy(dst, src); 8562ec810d5SMatthew Wilcox (Oracle) else 8572ec810d5SMatthew Wilcox (Oracle) folio_migrate_flags(dst, src); 8582ec810d5SMatthew Wilcox (Oracle) return MIGRATEPAGE_SUCCESS; 8592ec810d5SMatthew Wilcox (Oracle) } 8602ec810d5SMatthew Wilcox (Oracle) EXPORT_SYMBOL_GPL(filemap_migrate_folio); 8612ec810d5SMatthew Wilcox (Oracle) 86204e62a29SChristoph Lameter /* 8632be7fa10SMatthew Wilcox (Oracle) * Writeback a folio to clean the dirty state 86404e62a29SChristoph Lameter */ 8652be7fa10SMatthew Wilcox (Oracle) static int writeout(struct address_space *mapping, struct folio *folio) 86604e62a29SChristoph Lameter { 86704e62a29SChristoph Lameter struct writeback_control wbc = { 86804e62a29SChristoph Lameter .sync_mode = WB_SYNC_NONE, 86904e62a29SChristoph Lameter .nr_to_write = 1, 87004e62a29SChristoph Lameter .range_start = 0, 87104e62a29SChristoph Lameter .range_end = LLONG_MAX, 87204e62a29SChristoph Lameter .for_reclaim = 1 87304e62a29SChristoph Lameter }; 87404e62a29SChristoph Lameter int rc; 87504e62a29SChristoph Lameter 87604e62a29SChristoph Lameter if (!mapping->a_ops->writepage) 87704e62a29SChristoph Lameter /* No write method for the address space */ 87804e62a29SChristoph Lameter return -EINVAL; 87904e62a29SChristoph Lameter 8802be7fa10SMatthew Wilcox (Oracle) if (!folio_clear_dirty_for_io(folio)) 88104e62a29SChristoph Lameter /* Someone else already triggered a write */ 88204e62a29SChristoph Lameter return -EAGAIN; 88304e62a29SChristoph Lameter 88404e62a29SChristoph Lameter /* 8852be7fa10SMatthew Wilcox (Oracle) * A dirty folio may imply that the underlying filesystem has 8862be7fa10SMatthew Wilcox (Oracle) * the folio on some queue. So the folio must be clean for 8872be7fa10SMatthew Wilcox (Oracle) * migration. Writeout may mean we lose the lock and the 8882be7fa10SMatthew Wilcox (Oracle) * folio state is no longer what we checked for earlier. 88904e62a29SChristoph Lameter * At this point we know that the migration attempt cannot 89004e62a29SChristoph Lameter * be successful. 89104e62a29SChristoph Lameter */ 8924eecb8b9SMatthew Wilcox (Oracle) remove_migration_ptes(folio, folio, false); 89304e62a29SChristoph Lameter 8942be7fa10SMatthew Wilcox (Oracle) rc = mapping->a_ops->writepage(&folio->page, &wbc); 89504e62a29SChristoph Lameter 89604e62a29SChristoph Lameter if (rc != AOP_WRITEPAGE_ACTIVATE) 89704e62a29SChristoph Lameter /* unlocked. Relock */ 8982be7fa10SMatthew Wilcox (Oracle) folio_lock(folio); 89904e62a29SChristoph Lameter 900bda8550dSHugh Dickins return (rc < 0) ? -EIO : -EAGAIN; 90104e62a29SChristoph Lameter } 90204e62a29SChristoph Lameter 90304e62a29SChristoph Lameter /* 90404e62a29SChristoph Lameter * Default handling if a filesystem does not provide a migration function. 90504e62a29SChristoph Lameter */ 9068faa8ef5SMatthew Wilcox (Oracle) static int fallback_migrate_folio(struct address_space *mapping, 9078faa8ef5SMatthew Wilcox (Oracle) struct folio *dst, struct folio *src, enum migrate_mode mode) 9088351a6e4SChristoph Lameter { 9098faa8ef5SMatthew Wilcox (Oracle) if (folio_test_dirty(src)) { 9108faa8ef5SMatthew Wilcox (Oracle) /* Only writeback folios in full synchronous migration */ 9112916ecc0SJérôme Glisse switch (mode) { 9122916ecc0SJérôme Glisse case MIGRATE_SYNC: 9132916ecc0SJérôme Glisse case MIGRATE_SYNC_NO_COPY: 9142916ecc0SJérôme Glisse break; 9152916ecc0SJérôme Glisse default: 916b969c4abSMel Gorman return -EBUSY; 9172916ecc0SJérôme Glisse } 9182be7fa10SMatthew Wilcox (Oracle) return writeout(mapping, src); 919b969c4abSMel Gorman } 9208351a6e4SChristoph Lameter 9218351a6e4SChristoph Lameter /* 9228351a6e4SChristoph Lameter * Buffers may be managed in a filesystem specific way. 9238351a6e4SChristoph Lameter * We must have no buffers or drop them. 9248351a6e4SChristoph Lameter */ 9258faa8ef5SMatthew Wilcox (Oracle) if (folio_test_private(src) && 9268faa8ef5SMatthew Wilcox (Oracle) !filemap_release_folio(src, GFP_KERNEL)) 927806031bbSMel Gorman return mode == MIGRATE_SYNC ? -EAGAIN : -EBUSY; 9288351a6e4SChristoph Lameter 92954184650SMatthew Wilcox (Oracle) return migrate_folio(mapping, dst, src, mode); 9308351a6e4SChristoph Lameter } 9318351a6e4SChristoph Lameter 9321d8b85ccSChristoph Lameter /* 933e24f0b8fSChristoph Lameter * Move a page to a newly allocated page 934e24f0b8fSChristoph Lameter * The page is locked and all ptes have been successfully removed. 935b20a3503SChristoph Lameter * 936e24f0b8fSChristoph Lameter * The new page will have replaced the old page if this function 937e24f0b8fSChristoph Lameter * is successful. 938894bc310SLee Schermerhorn * 939894bc310SLee Schermerhorn * Return value: 940894bc310SLee Schermerhorn * < 0 - error code 94178bd5209SRafael Aquini * MIGRATEPAGE_SUCCESS - success 942b20a3503SChristoph Lameter */ 943e7e3ffebSMatthew Wilcox (Oracle) static int move_to_new_folio(struct folio *dst, struct folio *src, 9445c3f9a67SHugh Dickins enum migrate_mode mode) 945b20a3503SChristoph Lameter { 946bda807d4SMinchan Kim int rc = -EAGAIN; 947e7e3ffebSMatthew Wilcox (Oracle) bool is_lru = !__PageMovable(&src->page); 948b20a3503SChristoph Lameter 949e7e3ffebSMatthew Wilcox (Oracle) VM_BUG_ON_FOLIO(!folio_test_locked(src), src); 950e7e3ffebSMatthew Wilcox (Oracle) VM_BUG_ON_FOLIO(!folio_test_locked(dst), dst); 951b20a3503SChristoph Lameter 952bda807d4SMinchan Kim if (likely(is_lru)) { 95368f2736aSMatthew Wilcox (Oracle) struct address_space *mapping = folio_mapping(src); 95468f2736aSMatthew Wilcox (Oracle) 955b20a3503SChristoph Lameter if (!mapping) 95654184650SMatthew Wilcox (Oracle) rc = migrate_folio(mapping, dst, src, mode); 9575490da4fSMatthew Wilcox (Oracle) else if (mapping->a_ops->migrate_folio) 958b20a3503SChristoph Lameter /* 9595490da4fSMatthew Wilcox (Oracle) * Most folios have a mapping and most filesystems 9605490da4fSMatthew Wilcox (Oracle) * provide a migrate_folio callback. Anonymous folios 961bda807d4SMinchan Kim * are part of swap space which also has its own 9625490da4fSMatthew Wilcox (Oracle) * migrate_folio callback. This is the most common path 963bda807d4SMinchan Kim * for page migration. 964b20a3503SChristoph Lameter */ 9655490da4fSMatthew Wilcox (Oracle) rc = mapping->a_ops->migrate_folio(mapping, dst, src, 9665490da4fSMatthew Wilcox (Oracle) mode); 9678351a6e4SChristoph Lameter else 9688faa8ef5SMatthew Wilcox (Oracle) rc = fallback_migrate_folio(mapping, dst, src, mode); 969bda807d4SMinchan Kim } else { 97068f2736aSMatthew Wilcox (Oracle) const struct movable_operations *mops; 97168f2736aSMatthew Wilcox (Oracle) 972bda807d4SMinchan Kim /* 973bda807d4SMinchan Kim * In case of non-lru page, it could be released after 974bda807d4SMinchan Kim * isolation step. In that case, we shouldn't try migration. 975bda807d4SMinchan Kim */ 976e7e3ffebSMatthew Wilcox (Oracle) VM_BUG_ON_FOLIO(!folio_test_isolated(src), src); 977e7e3ffebSMatthew Wilcox (Oracle) if (!folio_test_movable(src)) { 978bda807d4SMinchan Kim rc = MIGRATEPAGE_SUCCESS; 979e7e3ffebSMatthew Wilcox (Oracle) folio_clear_isolated(src); 980bda807d4SMinchan Kim goto out; 981bda807d4SMinchan Kim } 982bda807d4SMinchan Kim 983da707a6dSVishal Moola (Oracle) mops = folio_movable_ops(src); 98468f2736aSMatthew Wilcox (Oracle) rc = mops->migrate_page(&dst->page, &src->page, mode); 985bda807d4SMinchan Kim WARN_ON_ONCE(rc == MIGRATEPAGE_SUCCESS && 986e7e3ffebSMatthew Wilcox (Oracle) !folio_test_isolated(src)); 987bda807d4SMinchan Kim } 988b20a3503SChristoph Lameter 9895c3f9a67SHugh Dickins /* 990e7e3ffebSMatthew Wilcox (Oracle) * When successful, old pagecache src->mapping must be cleared before 991e7e3ffebSMatthew Wilcox (Oracle) * src is freed; but stats require that PageAnon be left as PageAnon. 9925c3f9a67SHugh Dickins */ 9935c3f9a67SHugh Dickins if (rc == MIGRATEPAGE_SUCCESS) { 994e7e3ffebSMatthew Wilcox (Oracle) if (__PageMovable(&src->page)) { 995e7e3ffebSMatthew Wilcox (Oracle) VM_BUG_ON_FOLIO(!folio_test_isolated(src), src); 996bda807d4SMinchan Kim 997bda807d4SMinchan Kim /* 998bda807d4SMinchan Kim * We clear PG_movable under page_lock so any compactor 999bda807d4SMinchan Kim * cannot try to migrate this page. 1000bda807d4SMinchan Kim */ 1001e7e3ffebSMatthew Wilcox (Oracle) folio_clear_isolated(src); 1002bda807d4SMinchan Kim } 1003bda807d4SMinchan Kim 1004bda807d4SMinchan Kim /* 1005e7e3ffebSMatthew Wilcox (Oracle) * Anonymous and movable src->mapping will be cleared by 1006bda807d4SMinchan Kim * free_pages_prepare so don't reset it here for keeping 1007bda807d4SMinchan Kim * the type to work PageAnon, for example. 1008bda807d4SMinchan Kim */ 1009e7e3ffebSMatthew Wilcox (Oracle) if (!folio_mapping_flags(src)) 1010e7e3ffebSMatthew Wilcox (Oracle) src->mapping = NULL; 1011d2b2c6ddSLars Persson 1012e7e3ffebSMatthew Wilcox (Oracle) if (likely(!folio_is_zone_device(dst))) 1013e7e3ffebSMatthew Wilcox (Oracle) flush_dcache_folio(dst); 10143fe2011fSMel Gorman } 1015bda807d4SMinchan Kim out: 1016e24f0b8fSChristoph Lameter return rc; 1017e24f0b8fSChristoph Lameter } 1018e24f0b8fSChristoph Lameter 101964c8902eSHuang Ying /* 102064c8902eSHuang Ying * To record some information during migration, we use some unused 102164c8902eSHuang Ying * fields (mapping and private) of struct folio of the newly allocated 102264c8902eSHuang Ying * destination folio. This is safe because nobody is using them 102364c8902eSHuang Ying * except us. 102464c8902eSHuang Ying */ 1025e77d587aSLinus Torvalds union migration_ptr { 1026e77d587aSLinus Torvalds struct anon_vma *anon_vma; 1027e77d587aSLinus Torvalds struct address_space *mapping; 1028e77d587aSLinus Torvalds }; 102964c8902eSHuang Ying static void __migrate_folio_record(struct folio *dst, 103064c8902eSHuang Ying unsigned long page_was_mapped, 103164c8902eSHuang Ying struct anon_vma *anon_vma) 1032e24f0b8fSChristoph Lameter { 1033e77d587aSLinus Torvalds union migration_ptr ptr = { .anon_vma = anon_vma }; 1034e77d587aSLinus Torvalds dst->mapping = ptr.mapping; 103564c8902eSHuang Ying dst->private = (void *)page_was_mapped; 103664c8902eSHuang Ying } 103764c8902eSHuang Ying 103864c8902eSHuang Ying static void __migrate_folio_extract(struct folio *dst, 103964c8902eSHuang Ying int *page_was_mappedp, 104064c8902eSHuang Ying struct anon_vma **anon_vmap) 104164c8902eSHuang Ying { 1042e77d587aSLinus Torvalds union migration_ptr ptr = { .mapping = dst->mapping }; 1043e77d587aSLinus Torvalds *anon_vmap = ptr.anon_vma; 104464c8902eSHuang Ying *page_was_mappedp = (unsigned long)dst->private; 104564c8902eSHuang Ying dst->mapping = NULL; 104664c8902eSHuang Ying dst->private = NULL; 104764c8902eSHuang Ying } 104864c8902eSHuang Ying 10495dfab109SHuang Ying /* Restore the source folio to the original state upon failure */ 10505dfab109SHuang Ying static void migrate_folio_undo_src(struct folio *src, 10515dfab109SHuang Ying int page_was_mapped, 10525dfab109SHuang Ying struct anon_vma *anon_vma, 1053ebe75e47SHuang Ying bool locked, 10545dfab109SHuang Ying struct list_head *ret) 10555dfab109SHuang Ying { 10565dfab109SHuang Ying if (page_was_mapped) 10575dfab109SHuang Ying remove_migration_ptes(src, src, false); 10585dfab109SHuang Ying /* Drop an anon_vma reference if we took one */ 10595dfab109SHuang Ying if (anon_vma) 10605dfab109SHuang Ying put_anon_vma(anon_vma); 1061ebe75e47SHuang Ying if (locked) 10625dfab109SHuang Ying folio_unlock(src); 1063ebe75e47SHuang Ying if (ret) 10645dfab109SHuang Ying list_move_tail(&src->lru, ret); 10655dfab109SHuang Ying } 10665dfab109SHuang Ying 10675dfab109SHuang Ying /* Restore the destination folio to the original state upon failure */ 10684e096ae1SMatthew Wilcox (Oracle) static void migrate_folio_undo_dst(struct folio *dst, bool locked, 10694e096ae1SMatthew Wilcox (Oracle) free_folio_t put_new_folio, unsigned long private) 10705dfab109SHuang Ying { 1071ebe75e47SHuang Ying if (locked) 10725dfab109SHuang Ying folio_unlock(dst); 10734e096ae1SMatthew Wilcox (Oracle) if (put_new_folio) 10744e096ae1SMatthew Wilcox (Oracle) put_new_folio(dst, private); 10755dfab109SHuang Ying else 10765dfab109SHuang Ying folio_put(dst); 10775dfab109SHuang Ying } 10785dfab109SHuang Ying 107964c8902eSHuang Ying /* Cleanup src folio upon migration success */ 108064c8902eSHuang Ying static void migrate_folio_done(struct folio *src, 108164c8902eSHuang Ying enum migrate_reason reason) 108264c8902eSHuang Ying { 108364c8902eSHuang Ying /* 108464c8902eSHuang Ying * Compaction can migrate also non-LRU pages which are 108564c8902eSHuang Ying * not accounted to NR_ISOLATED_*. They can be recognized 108664c8902eSHuang Ying * as __PageMovable 108764c8902eSHuang Ying */ 108864c8902eSHuang Ying if (likely(!__folio_test_movable(src))) 108964c8902eSHuang Ying mod_node_page_state(folio_pgdat(src), NR_ISOLATED_ANON + 109064c8902eSHuang Ying folio_is_file_lru(src), -folio_nr_pages(src)); 109164c8902eSHuang Ying 109264c8902eSHuang Ying if (reason != MR_MEMORY_FAILURE) 109364c8902eSHuang Ying /* We release the page in page_handle_poison. */ 109464c8902eSHuang Ying folio_put(src); 109564c8902eSHuang Ying } 109664c8902eSHuang Ying 1097ebe75e47SHuang Ying /* Obtain the lock on page, remove all ptes. */ 10984e096ae1SMatthew Wilcox (Oracle) static int migrate_folio_unmap(new_folio_t get_new_folio, 10994e096ae1SMatthew Wilcox (Oracle) free_folio_t put_new_folio, unsigned long private, 11004e096ae1SMatthew Wilcox (Oracle) struct folio *src, struct folio **dstp, enum migrate_mode mode, 11012ef7dbb2SHuang Ying enum migrate_reason reason, struct list_head *ret) 1102e24f0b8fSChristoph Lameter { 1103ebe75e47SHuang Ying struct folio *dst; 11040dabec93SMinchan Kim int rc = -EAGAIN; 110564c8902eSHuang Ying int page_was_mapped = 0; 11063f6c8272SMel Gorman struct anon_vma *anon_vma = NULL; 1107682a71a1SMatthew Wilcox (Oracle) bool is_lru = !__PageMovable(&src->page); 1108ebe75e47SHuang Ying bool locked = false; 1109ebe75e47SHuang Ying bool dst_locked = false; 1110ebe75e47SHuang Ying 1111ebe75e47SHuang Ying if (folio_ref_count(src) == 1) { 1112ebe75e47SHuang Ying /* Folio was freed from under us. So we are done. */ 1113ebe75e47SHuang Ying folio_clear_active(src); 1114ebe75e47SHuang Ying folio_clear_unevictable(src); 1115ebe75e47SHuang Ying /* free_pages_prepare() will clear PG_isolated. */ 1116ebe75e47SHuang Ying list_del(&src->lru); 1117ebe75e47SHuang Ying migrate_folio_done(src, reason); 1118ebe75e47SHuang Ying return MIGRATEPAGE_SUCCESS; 1119ebe75e47SHuang Ying } 1120ebe75e47SHuang Ying 11214e096ae1SMatthew Wilcox (Oracle) dst = get_new_folio(src, private); 11224e096ae1SMatthew Wilcox (Oracle) if (!dst) 1123ebe75e47SHuang Ying return -ENOMEM; 1124ebe75e47SHuang Ying *dstp = dst; 1125ebe75e47SHuang Ying 1126ebe75e47SHuang Ying dst->private = NULL; 112795a402c3SChristoph Lameter 1128682a71a1SMatthew Wilcox (Oracle) if (!folio_trylock(src)) { 11292ef7dbb2SHuang Ying if (mode == MIGRATE_ASYNC) 11300dabec93SMinchan Kim goto out; 11313e7d3449SMel Gorman 11323e7d3449SMel Gorman /* 11333e7d3449SMel Gorman * It's not safe for direct compaction to call lock_page. 11343e7d3449SMel Gorman * For example, during page readahead pages are added locked 11353e7d3449SMel Gorman * to the LRU. Later, when the IO completes the pages are 11363e7d3449SMel Gorman * marked uptodate and unlocked. However, the queueing 11373e7d3449SMel Gorman * could be merging multiple pages for one bio (e.g. 1138d4388340SMatthew Wilcox (Oracle) * mpage_readahead). If an allocation happens for the 11393e7d3449SMel Gorman * second or third page, the process can end up locking 11403e7d3449SMel Gorman * the same page twice and deadlocking. Rather than 11413e7d3449SMel Gorman * trying to be clever about what pages can be locked, 11423e7d3449SMel Gorman * avoid the use of lock_page for direct compaction 11433e7d3449SMel Gorman * altogether. 11443e7d3449SMel Gorman */ 11453e7d3449SMel Gorman if (current->flags & PF_MEMALLOC) 11460dabec93SMinchan Kim goto out; 11473e7d3449SMel Gorman 11484bb6dc79SDouglas Anderson /* 11494bb6dc79SDouglas Anderson * In "light" mode, we can wait for transient locks (eg 11504bb6dc79SDouglas Anderson * inserting a page into the page table), but it's not 11514bb6dc79SDouglas Anderson * worth waiting for I/O. 11524bb6dc79SDouglas Anderson */ 11534bb6dc79SDouglas Anderson if (mode == MIGRATE_SYNC_LIGHT && !folio_test_uptodate(src)) 11544bb6dc79SDouglas Anderson goto out; 11554bb6dc79SDouglas Anderson 1156682a71a1SMatthew Wilcox (Oracle) folio_lock(src); 1157e24f0b8fSChristoph Lameter } 1158ebe75e47SHuang Ying locked = true; 1159e24f0b8fSChristoph Lameter 1160682a71a1SMatthew Wilcox (Oracle) if (folio_test_writeback(src)) { 116111bc82d6SAndrea Arcangeli /* 1162fed5b64aSJianguo Wu * Only in the case of a full synchronous migration is it 1163a6bc32b8SMel Gorman * necessary to wait for PageWriteback. In the async case, 1164a6bc32b8SMel Gorman * the retry loop is too short and in the sync-light case, 1165a6bc32b8SMel Gorman * the overhead of stalling is too much 116611bc82d6SAndrea Arcangeli */ 11672916ecc0SJérôme Glisse switch (mode) { 11682916ecc0SJérôme Glisse case MIGRATE_SYNC: 11692916ecc0SJérôme Glisse case MIGRATE_SYNC_NO_COPY: 11702916ecc0SJérôme Glisse break; 11712916ecc0SJérôme Glisse default: 117211bc82d6SAndrea Arcangeli rc = -EBUSY; 1173ebe75e47SHuang Ying goto out; 117411bc82d6SAndrea Arcangeli } 1175682a71a1SMatthew Wilcox (Oracle) folio_wait_writeback(src); 1176e24f0b8fSChristoph Lameter } 117703f15c86SHugh Dickins 1178e24f0b8fSChristoph Lameter /* 1179682a71a1SMatthew Wilcox (Oracle) * By try_to_migrate(), src->mapcount goes down to 0 here. In this case, 1180682a71a1SMatthew Wilcox (Oracle) * we cannot notice that anon_vma is freed while we migrate a page. 11811ce82b69SHugh Dickins * This get_anon_vma() delays freeing anon_vma pointer until the end 1182dc386d4dSKAMEZAWA Hiroyuki * of migration. File cache pages are no problem because of page_lock() 1183989f89c5SKAMEZAWA Hiroyuki * File Caches may use write_page() or lock_page() in migration, then, 1184989f89c5SKAMEZAWA Hiroyuki * just care Anon page here. 11853fe2011fSMel Gorman * 118629eea9b5SMatthew Wilcox (Oracle) * Only folio_get_anon_vma() understands the subtleties of 118703f15c86SHugh Dickins * getting a hold on an anon_vma from outside one of its mms. 118803f15c86SHugh Dickins * But if we cannot get anon_vma, then we won't need it anyway, 118903f15c86SHugh Dickins * because that implies that the anon page is no longer mapped 119003f15c86SHugh Dickins * (and cannot be remapped so long as we hold the page lock). 11913fe2011fSMel Gorman */ 1192682a71a1SMatthew Wilcox (Oracle) if (folio_test_anon(src) && !folio_test_ksm(src)) 119329eea9b5SMatthew Wilcox (Oracle) anon_vma = folio_get_anon_vma(src); 119462e1c553SShaohua Li 11957db7671fSHugh Dickins /* 11967db7671fSHugh Dickins * Block others from accessing the new page when we get around to 11977db7671fSHugh Dickins * establishing additional references. We are usually the only one 1198682a71a1SMatthew Wilcox (Oracle) * holding a reference to dst at this point. We used to have a BUG 1199682a71a1SMatthew Wilcox (Oracle) * here if folio_trylock(dst) fails, but would like to allow for 1200682a71a1SMatthew Wilcox (Oracle) * cases where there might be a race with the previous use of dst. 12017db7671fSHugh Dickins * This is much like races on refcount of oldpage: just don't BUG(). 12027db7671fSHugh Dickins */ 1203682a71a1SMatthew Wilcox (Oracle) if (unlikely(!folio_trylock(dst))) 1204ebe75e47SHuang Ying goto out; 1205ebe75e47SHuang Ying dst_locked = true; 12067db7671fSHugh Dickins 1207bda807d4SMinchan Kim if (unlikely(!is_lru)) { 120864c8902eSHuang Ying __migrate_folio_record(dst, page_was_mapped, anon_vma); 120964c8902eSHuang Ying return MIGRATEPAGE_UNMAP; 1210bda807d4SMinchan Kim } 1211bda807d4SMinchan Kim 1212dc386d4dSKAMEZAWA Hiroyuki /* 121362e1c553SShaohua Li * Corner case handling: 121462e1c553SShaohua Li * 1. When a new swap-cache page is read into, it is added to the LRU 121562e1c553SShaohua Li * and treated as swapcache but it has no rmap yet. 1216682a71a1SMatthew Wilcox (Oracle) * Calling try_to_unmap() against a src->mapping==NULL page will 121762e1c553SShaohua Li * trigger a BUG. So handle it here. 1218d12b8951SYang Shi * 2. An orphaned page (see truncate_cleanup_page) might have 121962e1c553SShaohua Li * fs-private metadata. The page can be picked up due to memory 122062e1c553SShaohua Li * offlining. Everywhere else except page reclaim, the page is 122162e1c553SShaohua Li * invisible to the vm, so the page can not be migrated. So try to 122262e1c553SShaohua Li * free the metadata, so the page can be freed. 1223dc386d4dSKAMEZAWA Hiroyuki */ 1224682a71a1SMatthew Wilcox (Oracle) if (!src->mapping) { 1225682a71a1SMatthew Wilcox (Oracle) if (folio_test_private(src)) { 1226682a71a1SMatthew Wilcox (Oracle) try_to_free_buffers(src); 1227ebe75e47SHuang Ying goto out; 122862e1c553SShaohua Li } 1229682a71a1SMatthew Wilcox (Oracle) } else if (folio_mapped(src)) { 12307db7671fSHugh Dickins /* Establish migration ptes */ 1231682a71a1SMatthew Wilcox (Oracle) VM_BUG_ON_FOLIO(folio_test_anon(src) && 1232682a71a1SMatthew Wilcox (Oracle) !folio_test_ksm(src) && !anon_vma, src); 1233fb3592c4SHuang Ying try_to_migrate(src, mode == MIGRATE_ASYNC ? TTU_BATCH_FLUSH : 0); 123464c8902eSHuang Ying page_was_mapped = 1; 12352ebba6b7SHugh Dickins } 1236dc386d4dSKAMEZAWA Hiroyuki 123764c8902eSHuang Ying if (!folio_mapped(src)) { 123864c8902eSHuang Ying __migrate_folio_record(dst, page_was_mapped, anon_vma); 123964c8902eSHuang Ying return MIGRATEPAGE_UNMAP; 124064c8902eSHuang Ying } 124164c8902eSHuang Ying 124264c8902eSHuang Ying out: 124380562ba0SHuang Ying /* 124480562ba0SHuang Ying * A folio that has not been unmapped will be restored to 124580562ba0SHuang Ying * right list unless we want to retry. 124680562ba0SHuang Ying */ 1247fb3592c4SHuang Ying if (rc == -EAGAIN) 1248ebe75e47SHuang Ying ret = NULL; 124980562ba0SHuang Ying 1250ebe75e47SHuang Ying migrate_folio_undo_src(src, page_was_mapped, anon_vma, locked, ret); 12514e096ae1SMatthew Wilcox (Oracle) migrate_folio_undo_dst(dst, dst_locked, put_new_folio, private); 125280562ba0SHuang Ying 125380562ba0SHuang Ying return rc; 125480562ba0SHuang Ying } 125580562ba0SHuang Ying 1256ebe75e47SHuang Ying /* Migrate the folio to the newly allocated folio in dst. */ 12574e096ae1SMatthew Wilcox (Oracle) static int migrate_folio_move(free_folio_t put_new_folio, unsigned long private, 1258ebe75e47SHuang Ying struct folio *src, struct folio *dst, 1259ebe75e47SHuang Ying enum migrate_mode mode, enum migrate_reason reason, 1260ebe75e47SHuang Ying struct list_head *ret) 126164c8902eSHuang Ying { 126264c8902eSHuang Ying int rc; 126364c8902eSHuang Ying int page_was_mapped = 0; 126464c8902eSHuang Ying struct anon_vma *anon_vma = NULL; 126564c8902eSHuang Ying bool is_lru = !__PageMovable(&src->page); 12665dfab109SHuang Ying struct list_head *prev; 126764c8902eSHuang Ying 126864c8902eSHuang Ying __migrate_folio_extract(dst, &page_was_mapped, &anon_vma); 12695dfab109SHuang Ying prev = dst->lru.prev; 12705dfab109SHuang Ying list_del(&dst->lru); 127164c8902eSHuang Ying 1272682a71a1SMatthew Wilcox (Oracle) rc = move_to_new_folio(dst, src, mode); 1273ebe75e47SHuang Ying if (rc) 1274ebe75e47SHuang Ying goto out; 12755dfab109SHuang Ying 127664c8902eSHuang Ying if (unlikely(!is_lru)) 127764c8902eSHuang Ying goto out_unlock_both; 1278e24f0b8fSChristoph Lameter 1279c3096e67SHugh Dickins /* 1280682a71a1SMatthew Wilcox (Oracle) * When successful, push dst to LRU immediately: so that if it 1281c3096e67SHugh Dickins * turns out to be an mlocked page, remove_migration_ptes() will 1282682a71a1SMatthew Wilcox (Oracle) * automatically build up the correct dst->mlock_count for it. 1283c3096e67SHugh Dickins * 1284c3096e67SHugh Dickins * We would like to do something similar for the old page, when 1285c3096e67SHugh Dickins * unsuccessful, and other cases when a page has been temporarily 1286c3096e67SHugh Dickins * isolated from the unevictable LRU: but this case is the easiest. 1287c3096e67SHugh Dickins */ 1288682a71a1SMatthew Wilcox (Oracle) folio_add_lru(dst); 12895c3f9a67SHugh Dickins if (page_was_mapped) 1290c3096e67SHugh Dickins lru_add_drain(); 1291c3096e67SHugh Dickins 12925c3f9a67SHugh Dickins if (page_was_mapped) 1293ebe75e47SHuang Ying remove_migration_ptes(src, dst, false); 12943f6c8272SMel Gorman 12957db7671fSHugh Dickins out_unlock_both: 1296682a71a1SMatthew Wilcox (Oracle) folio_unlock(dst); 1297ebe75e47SHuang Ying set_page_owner_migrate_reason(&dst->page, reason); 1298c6c919ebSMinchan Kim /* 1299682a71a1SMatthew Wilcox (Oracle) * If migration is successful, decrease refcount of dst, 1300c6c919ebSMinchan Kim * which will not free the page because new page owner increased 1301c3096e67SHugh Dickins * refcounter. 1302c6c919ebSMinchan Kim */ 1303682a71a1SMatthew Wilcox (Oracle) folio_put(dst); 1304c6c919ebSMinchan Kim 1305ebe75e47SHuang Ying /* 1306ebe75e47SHuang Ying * A folio that has been migrated has all references removed 1307ebe75e47SHuang Ying * and will be freed. 1308ebe75e47SHuang Ying */ 1309ebe75e47SHuang Ying list_del(&src->lru); 1310ebe75e47SHuang Ying /* Drop an anon_vma reference if we took one */ 1311ebe75e47SHuang Ying if (anon_vma) 1312ebe75e47SHuang Ying put_anon_vma(anon_vma); 1313ebe75e47SHuang Ying folio_unlock(src); 1314ebe75e47SHuang Ying migrate_folio_done(src, reason); 1315ebe75e47SHuang Ying 1316ebe75e47SHuang Ying return rc; 1317ebe75e47SHuang Ying out: 1318ebe75e47SHuang Ying /* 1319ebe75e47SHuang Ying * A folio that has not been migrated will be restored to 1320ebe75e47SHuang Ying * right list unless we want to retry. 1321ebe75e47SHuang Ying */ 1322ebe75e47SHuang Ying if (rc == -EAGAIN) { 1323ebe75e47SHuang Ying list_add(&dst->lru, prev); 1324ebe75e47SHuang Ying __migrate_folio_record(dst, page_was_mapped, anon_vma); 13250dabec93SMinchan Kim return rc; 13260dabec93SMinchan Kim } 132795a402c3SChristoph Lameter 1328ebe75e47SHuang Ying migrate_folio_undo_src(src, page_was_mapped, anon_vma, true, ret); 13294e096ae1SMatthew Wilcox (Oracle) migrate_folio_undo_dst(dst, true, put_new_folio, private); 133068711a74SDavid Rientjes 1331e24f0b8fSChristoph Lameter return rc; 1332e24f0b8fSChristoph Lameter } 1333b20a3503SChristoph Lameter 1334e24f0b8fSChristoph Lameter /* 1335290408d4SNaoya Horiguchi * Counterpart of unmap_and_move_page() for hugepage migration. 1336290408d4SNaoya Horiguchi * 1337290408d4SNaoya Horiguchi * This function doesn't wait the completion of hugepage I/O 1338290408d4SNaoya Horiguchi * because there is no race between I/O and migration for hugepage. 1339290408d4SNaoya Horiguchi * Note that currently hugepage I/O occurs only in direct I/O 1340290408d4SNaoya Horiguchi * where no lock is held and PG_writeback is irrelevant, 1341290408d4SNaoya Horiguchi * and writeback status of all subpages are counted in the reference 1342290408d4SNaoya Horiguchi * count of the head page (i.e. if all subpages of a 2MB hugepage are 1343290408d4SNaoya Horiguchi * under direct I/O, the reference of the head page is 512 and a bit more.) 1344290408d4SNaoya Horiguchi * This means that when we try to migrate hugepage whose subpages are 1345290408d4SNaoya Horiguchi * doing direct I/O, some references remain after try_to_unmap() and 1346290408d4SNaoya Horiguchi * hugepage migration fails without data corruption. 1347290408d4SNaoya Horiguchi * 1348290408d4SNaoya Horiguchi * There is also no race when direct I/O is issued on the page under migration, 1349290408d4SNaoya Horiguchi * because then pte is replaced with migration swap entry and direct I/O code 1350290408d4SNaoya Horiguchi * will wait in the page fault for migration to complete. 1351290408d4SNaoya Horiguchi */ 13524e096ae1SMatthew Wilcox (Oracle) static int unmap_and_move_huge_page(new_folio_t get_new_folio, 13534e096ae1SMatthew Wilcox (Oracle) free_folio_t put_new_folio, unsigned long private, 13544e096ae1SMatthew Wilcox (Oracle) struct folio *src, int force, enum migrate_mode mode, 13554e096ae1SMatthew Wilcox (Oracle) int reason, struct list_head *ret) 1356290408d4SNaoya Horiguchi { 13574e096ae1SMatthew Wilcox (Oracle) struct folio *dst; 13582def7424SHugh Dickins int rc = -EAGAIN; 13592ebba6b7SHugh Dickins int page_was_mapped = 0; 1360290408d4SNaoya Horiguchi struct anon_vma *anon_vma = NULL; 1361c0d0381aSMike Kravetz struct address_space *mapping = NULL; 1362290408d4SNaoya Horiguchi 1363c33db292SMatthew Wilcox (Oracle) if (folio_ref_count(src) == 1) { 136471a64f61SMuchun Song /* page was freed from under us. So we are done. */ 1365ea8e72f4SSidhartha Kumar folio_putback_active_hugetlb(src); 136671a64f61SMuchun Song return MIGRATEPAGE_SUCCESS; 136771a64f61SMuchun Song } 136871a64f61SMuchun Song 13694e096ae1SMatthew Wilcox (Oracle) dst = get_new_folio(src, private); 13704e096ae1SMatthew Wilcox (Oracle) if (!dst) 1371290408d4SNaoya Horiguchi return -ENOMEM; 1372290408d4SNaoya Horiguchi 1373c33db292SMatthew Wilcox (Oracle) if (!folio_trylock(src)) { 13742916ecc0SJérôme Glisse if (!force) 1375290408d4SNaoya Horiguchi goto out; 13762916ecc0SJérôme Glisse switch (mode) { 13772916ecc0SJérôme Glisse case MIGRATE_SYNC: 13782916ecc0SJérôme Glisse case MIGRATE_SYNC_NO_COPY: 13792916ecc0SJérôme Glisse break; 13802916ecc0SJérôme Glisse default: 13812916ecc0SJérôme Glisse goto out; 13822916ecc0SJérôme Glisse } 1383c33db292SMatthew Wilcox (Oracle) folio_lock(src); 1384290408d4SNaoya Horiguchi } 1385290408d4SNaoya Horiguchi 1386cb6acd01SMike Kravetz /* 1387cb6acd01SMike Kravetz * Check for pages which are in the process of being freed. Without 1388c33db292SMatthew Wilcox (Oracle) * folio_mapping() set, hugetlbfs specific move page routine will not 1389cb6acd01SMike Kravetz * be called and we could leak usage counts for subpools. 1390cb6acd01SMike Kravetz */ 1391345c62d1SSidhartha Kumar if (hugetlb_folio_subpool(src) && !folio_mapping(src)) { 1392cb6acd01SMike Kravetz rc = -EBUSY; 1393cb6acd01SMike Kravetz goto out_unlock; 1394cb6acd01SMike Kravetz } 1395cb6acd01SMike Kravetz 1396c33db292SMatthew Wilcox (Oracle) if (folio_test_anon(src)) 139729eea9b5SMatthew Wilcox (Oracle) anon_vma = folio_get_anon_vma(src); 1398290408d4SNaoya Horiguchi 1399c33db292SMatthew Wilcox (Oracle) if (unlikely(!folio_trylock(dst))) 14007db7671fSHugh Dickins goto put_anon; 14017db7671fSHugh Dickins 1402c33db292SMatthew Wilcox (Oracle) if (folio_mapped(src)) { 1403a98a2f0cSAlistair Popple enum ttu_flags ttu = 0; 1404336bf30eSMike Kravetz 1405c33db292SMatthew Wilcox (Oracle) if (!folio_test_anon(src)) { 1406c0d0381aSMike Kravetz /* 1407336bf30eSMike Kravetz * In shared mappings, try_to_unmap could potentially 1408336bf30eSMike Kravetz * call huge_pmd_unshare. Because of this, take 1409336bf30eSMike Kravetz * semaphore in write mode here and set TTU_RMAP_LOCKED 1410336bf30eSMike Kravetz * to let lower levels know we have taken the lock. 1411c0d0381aSMike Kravetz */ 14124e096ae1SMatthew Wilcox (Oracle) mapping = hugetlb_page_mapping_lock_write(&src->page); 1413c0d0381aSMike Kravetz if (unlikely(!mapping)) 1414c0d0381aSMike Kravetz goto unlock_put_anon; 1415c0d0381aSMike Kravetz 14165202978bSMiaohe Lin ttu = TTU_RMAP_LOCKED; 1417336bf30eSMike Kravetz } 1418336bf30eSMike Kravetz 14194b8554c5SMatthew Wilcox (Oracle) try_to_migrate(src, ttu); 14202ebba6b7SHugh Dickins page_was_mapped = 1; 1421336bf30eSMike Kravetz 14225202978bSMiaohe Lin if (ttu & TTU_RMAP_LOCKED) 1423336bf30eSMike Kravetz i_mmap_unlock_write(mapping); 14242ebba6b7SHugh Dickins } 1425290408d4SNaoya Horiguchi 1426c33db292SMatthew Wilcox (Oracle) if (!folio_mapped(src)) 1427e7e3ffebSMatthew Wilcox (Oracle) rc = move_to_new_folio(dst, src, mode); 1428290408d4SNaoya Horiguchi 1429336bf30eSMike Kravetz if (page_was_mapped) 14304eecb8b9SMatthew Wilcox (Oracle) remove_migration_ptes(src, 14314eecb8b9SMatthew Wilcox (Oracle) rc == MIGRATEPAGE_SUCCESS ? dst : src, false); 1432290408d4SNaoya Horiguchi 1433c0d0381aSMike Kravetz unlock_put_anon: 1434c33db292SMatthew Wilcox (Oracle) folio_unlock(dst); 14357db7671fSHugh Dickins 14367db7671fSHugh Dickins put_anon: 1437fd4a4663SHugh Dickins if (anon_vma) 14389e60109fSPeter Zijlstra put_anon_vma(anon_vma); 14398e6ac7faSAneesh Kumar K.V 14402def7424SHugh Dickins if (rc == MIGRATEPAGE_SUCCESS) { 1441345c62d1SSidhartha Kumar move_hugetlb_state(src, dst, reason); 14424e096ae1SMatthew Wilcox (Oracle) put_new_folio = NULL; 14432def7424SHugh Dickins } 14448e6ac7faSAneesh Kumar K.V 1445cb6acd01SMike Kravetz out_unlock: 1446c33db292SMatthew Wilcox (Oracle) folio_unlock(src); 144709761333SHillf Danton out: 1448dd4ae78aSYang Shi if (rc == MIGRATEPAGE_SUCCESS) 1449ea8e72f4SSidhartha Kumar folio_putback_active_hugetlb(src); 1450a04840c6SMiaohe Lin else if (rc != -EAGAIN) 1451c33db292SMatthew Wilcox (Oracle) list_move_tail(&src->lru, ret); 145268711a74SDavid Rientjes 145368711a74SDavid Rientjes /* 145468711a74SDavid Rientjes * If migration was not successful and there's a freeing callback, use 145568711a74SDavid Rientjes * it. Otherwise, put_page() will drop the reference grabbed during 145668711a74SDavid Rientjes * isolation. 145768711a74SDavid Rientjes */ 14584e096ae1SMatthew Wilcox (Oracle) if (put_new_folio) 14594e096ae1SMatthew Wilcox (Oracle) put_new_folio(dst, private); 146068711a74SDavid Rientjes else 1461ea8e72f4SSidhartha Kumar folio_putback_active_hugetlb(dst); 146268711a74SDavid Rientjes 1463290408d4SNaoya Horiguchi return rc; 1464290408d4SNaoya Horiguchi } 1465290408d4SNaoya Horiguchi 1466eaec4e63SHuang Ying static inline int try_split_folio(struct folio *folio, struct list_head *split_folios) 1467d532e2e5SYang Shi { 14689c62ff00SHuang Ying int rc; 1469d532e2e5SYang Shi 1470eaec4e63SHuang Ying folio_lock(folio); 1471eaec4e63SHuang Ying rc = split_folio_to_list(folio, split_folios); 1472eaec4e63SHuang Ying folio_unlock(folio); 1473e6fa8a79SHuang Ying if (!rc) 1474eaec4e63SHuang Ying list_move_tail(&folio->lru, split_folios); 1475d532e2e5SYang Shi 1476d532e2e5SYang Shi return rc; 1477d532e2e5SYang Shi } 1478d532e2e5SYang Shi 147942012e04SHuang Ying #ifdef CONFIG_TRANSPARENT_HUGEPAGE 148042012e04SHuang Ying #define NR_MAX_BATCHED_MIGRATION HPAGE_PMD_NR 148142012e04SHuang Ying #else 148242012e04SHuang Ying #define NR_MAX_BATCHED_MIGRATION 512 148342012e04SHuang Ying #endif 1484e5bfff8bSHuang Ying #define NR_MAX_MIGRATE_PAGES_RETRY 10 14852ef7dbb2SHuang Ying #define NR_MAX_MIGRATE_ASYNC_RETRY 3 14862ef7dbb2SHuang Ying #define NR_MAX_MIGRATE_SYNC_RETRY \ 14872ef7dbb2SHuang Ying (NR_MAX_MIGRATE_PAGES_RETRY - NR_MAX_MIGRATE_ASYNC_RETRY) 1488e5bfff8bSHuang Ying 14895b855937SHuang Ying struct migrate_pages_stats { 14905b855937SHuang Ying int nr_succeeded; /* Normal and large folios migrated successfully, in 14915b855937SHuang Ying units of base pages */ 14925b855937SHuang Ying int nr_failed_pages; /* Normal and large folios failed to be migrated, in 14935b855937SHuang Ying units of base pages. Untried folios aren't counted */ 14945b855937SHuang Ying int nr_thp_succeeded; /* THP migrated successfully */ 14955b855937SHuang Ying int nr_thp_failed; /* THP failed to be migrated */ 14965b855937SHuang Ying int nr_thp_split; /* THP split before migrating */ 14975b855937SHuang Ying }; 14985b855937SHuang Ying 1499290408d4SNaoya Horiguchi /* 1500e5bfff8bSHuang Ying * Returns the number of hugetlb folios that were not migrated, or an error code 1501e5bfff8bSHuang Ying * after NR_MAX_MIGRATE_PAGES_RETRY attempts or if no hugetlb folios are movable 1502e5bfff8bSHuang Ying * any more because the list has become empty or no retryable hugetlb folios 1503e5bfff8bSHuang Ying * exist any more. It is caller's responsibility to call putback_movable_pages() 1504e5bfff8bSHuang Ying * only if ret != 0. 1505e5bfff8bSHuang Ying */ 15064e096ae1SMatthew Wilcox (Oracle) static int migrate_hugetlbs(struct list_head *from, new_folio_t get_new_folio, 15074e096ae1SMatthew Wilcox (Oracle) free_folio_t put_new_folio, unsigned long private, 1508e5bfff8bSHuang Ying enum migrate_mode mode, int reason, 1509e5bfff8bSHuang Ying struct migrate_pages_stats *stats, 1510e5bfff8bSHuang Ying struct list_head *ret_folios) 1511e5bfff8bSHuang Ying { 1512e5bfff8bSHuang Ying int retry = 1; 1513e5bfff8bSHuang Ying int nr_failed = 0; 1514e5bfff8bSHuang Ying int nr_retry_pages = 0; 1515e5bfff8bSHuang Ying int pass = 0; 1516e5bfff8bSHuang Ying struct folio *folio, *folio2; 1517e5bfff8bSHuang Ying int rc, nr_pages; 1518e5bfff8bSHuang Ying 1519e5bfff8bSHuang Ying for (pass = 0; pass < NR_MAX_MIGRATE_PAGES_RETRY && retry; pass++) { 1520e5bfff8bSHuang Ying retry = 0; 1521e5bfff8bSHuang Ying nr_retry_pages = 0; 1522e5bfff8bSHuang Ying 1523e5bfff8bSHuang Ying list_for_each_entry_safe(folio, folio2, from, lru) { 1524e5bfff8bSHuang Ying if (!folio_test_hugetlb(folio)) 1525e5bfff8bSHuang Ying continue; 1526e5bfff8bSHuang Ying 1527e5bfff8bSHuang Ying nr_pages = folio_nr_pages(folio); 1528e5bfff8bSHuang Ying 1529e5bfff8bSHuang Ying cond_resched(); 1530e5bfff8bSHuang Ying 15316f7d760eSHuang Ying /* 15326f7d760eSHuang Ying * Migratability of hugepages depends on architectures and 15336f7d760eSHuang Ying * their size. This check is necessary because some callers 15346f7d760eSHuang Ying * of hugepage migration like soft offline and memory 15356f7d760eSHuang Ying * hotremove don't walk through page tables or check whether 15366f7d760eSHuang Ying * the hugepage is pmd-based or not before kicking migration. 15376f7d760eSHuang Ying */ 15386f7d760eSHuang Ying if (!hugepage_migration_supported(folio_hstate(folio))) { 15396f7d760eSHuang Ying nr_failed++; 15406f7d760eSHuang Ying stats->nr_failed_pages += nr_pages; 15416f7d760eSHuang Ying list_move_tail(&folio->lru, ret_folios); 15426f7d760eSHuang Ying continue; 15436f7d760eSHuang Ying } 15446f7d760eSHuang Ying 15454e096ae1SMatthew Wilcox (Oracle) rc = unmap_and_move_huge_page(get_new_folio, 15464e096ae1SMatthew Wilcox (Oracle) put_new_folio, private, 15474e096ae1SMatthew Wilcox (Oracle) folio, pass > 2, mode, 1548e5bfff8bSHuang Ying reason, ret_folios); 1549e5bfff8bSHuang Ying /* 1550e5bfff8bSHuang Ying * The rules are: 1551e5bfff8bSHuang Ying * Success: hugetlb folio will be put back 1552e5bfff8bSHuang Ying * -EAGAIN: stay on the from list 1553e5bfff8bSHuang Ying * -ENOMEM: stay on the from list 1554e5bfff8bSHuang Ying * Other errno: put on ret_folios list 1555e5bfff8bSHuang Ying */ 1556e5bfff8bSHuang Ying switch(rc) { 1557e5bfff8bSHuang Ying case -ENOMEM: 1558e5bfff8bSHuang Ying /* 1559e5bfff8bSHuang Ying * When memory is low, don't bother to try to migrate 1560e5bfff8bSHuang Ying * other folios, just exit. 1561e5bfff8bSHuang Ying */ 1562e5bfff8bSHuang Ying stats->nr_failed_pages += nr_pages + nr_retry_pages; 1563e5bfff8bSHuang Ying return -ENOMEM; 1564e5bfff8bSHuang Ying case -EAGAIN: 1565e5bfff8bSHuang Ying retry++; 1566e5bfff8bSHuang Ying nr_retry_pages += nr_pages; 1567e5bfff8bSHuang Ying break; 1568e5bfff8bSHuang Ying case MIGRATEPAGE_SUCCESS: 1569e5bfff8bSHuang Ying stats->nr_succeeded += nr_pages; 1570e5bfff8bSHuang Ying break; 1571e5bfff8bSHuang Ying default: 1572e5bfff8bSHuang Ying /* 1573e5bfff8bSHuang Ying * Permanent failure (-EBUSY, etc.): 1574e5bfff8bSHuang Ying * unlike -EAGAIN case, the failed folio is 1575e5bfff8bSHuang Ying * removed from migration folio list and not 1576e5bfff8bSHuang Ying * retried in the next outer loop. 1577e5bfff8bSHuang Ying */ 1578e5bfff8bSHuang Ying nr_failed++; 1579e5bfff8bSHuang Ying stats->nr_failed_pages += nr_pages; 1580e5bfff8bSHuang Ying break; 1581e5bfff8bSHuang Ying } 1582e5bfff8bSHuang Ying } 1583e5bfff8bSHuang Ying } 1584e5bfff8bSHuang Ying /* 1585e5bfff8bSHuang Ying * nr_failed is number of hugetlb folios failed to be migrated. After 1586e5bfff8bSHuang Ying * NR_MAX_MIGRATE_PAGES_RETRY attempts, give up and count retried hugetlb 1587e5bfff8bSHuang Ying * folios as failed. 1588e5bfff8bSHuang Ying */ 1589e5bfff8bSHuang Ying nr_failed += retry; 1590e5bfff8bSHuang Ying stats->nr_failed_pages += nr_retry_pages; 1591e5bfff8bSHuang Ying 1592e5bfff8bSHuang Ying return nr_failed; 1593e5bfff8bSHuang Ying } 1594e5bfff8bSHuang Ying 15955dfab109SHuang Ying /* 15965dfab109SHuang Ying * migrate_pages_batch() first unmaps folios in the from list as many as 15975dfab109SHuang Ying * possible, then move the unmapped folios. 1598fb3592c4SHuang Ying * 1599fb3592c4SHuang Ying * We only batch migration if mode == MIGRATE_ASYNC to avoid to wait a 1600fb3592c4SHuang Ying * lock or bit when we have locked more than one folio. Which may cause 1601fb3592c4SHuang Ying * deadlock (e.g., for loop device). So, if mode != MIGRATE_ASYNC, the 1602fb3592c4SHuang Ying * length of the from list must be <= 1. 16035dfab109SHuang Ying */ 16044e096ae1SMatthew Wilcox (Oracle) static int migrate_pages_batch(struct list_head *from, 16054e096ae1SMatthew Wilcox (Oracle) new_folio_t get_new_folio, free_folio_t put_new_folio, 16064e096ae1SMatthew Wilcox (Oracle) unsigned long private, enum migrate_mode mode, int reason, 16074e096ae1SMatthew Wilcox (Oracle) struct list_head *ret_folios, struct list_head *split_folios, 16084e096ae1SMatthew Wilcox (Oracle) struct migrate_pages_stats *stats, int nr_pass) 160942012e04SHuang Ying { 1610a21d2133SHuang Ying int retry = 1; 161142012e04SHuang Ying int thp_retry = 1; 161242012e04SHuang Ying int nr_failed = 0; 161342012e04SHuang Ying int nr_retry_pages = 0; 161442012e04SHuang Ying int pass = 0; 161542012e04SHuang Ying bool is_thp = false; 16165dfab109SHuang Ying struct folio *folio, *folio2, *dst = NULL, *dst2; 1617a21d2133SHuang Ying int rc, rc_saved = 0, nr_pages; 16185dfab109SHuang Ying LIST_HEAD(unmap_folios); 16195dfab109SHuang Ying LIST_HEAD(dst_folios); 162042012e04SHuang Ying bool nosplit = (reason == MR_NUMA_MISPLACED); 162142012e04SHuang Ying 1622fb3592c4SHuang Ying VM_WARN_ON_ONCE(mode != MIGRATE_ASYNC && 1623fb3592c4SHuang Ying !list_empty(from) && !list_is_singular(from)); 1624a21d2133SHuang Ying 1625124abcedSHuang Ying for (pass = 0; pass < nr_pass && retry; pass++) { 162642012e04SHuang Ying retry = 0; 162742012e04SHuang Ying thp_retry = 0; 162842012e04SHuang Ying nr_retry_pages = 0; 162942012e04SHuang Ying 163042012e04SHuang Ying list_for_each_entry_safe(folio, folio2, from, lru) { 1631124abcedSHuang Ying is_thp = folio_test_large(folio) && folio_test_pmd_mappable(folio); 163242012e04SHuang Ying nr_pages = folio_nr_pages(folio); 163342012e04SHuang Ying 163442012e04SHuang Ying cond_resched(); 163542012e04SHuang Ying 16366f7d760eSHuang Ying /* 16376f7d760eSHuang Ying * Large folio migration might be unsupported or 16386f7d760eSHuang Ying * the allocation might be failed so we should retry 16396f7d760eSHuang Ying * on the same folio with the large folio split 16406f7d760eSHuang Ying * to normal folios. 16416f7d760eSHuang Ying * 16426f7d760eSHuang Ying * Split folios are put in split_folios, and 16436f7d760eSHuang Ying * we will migrate them after the rest of the 16446f7d760eSHuang Ying * list is processed. 16456f7d760eSHuang Ying */ 16466f7d760eSHuang Ying if (!thp_migration_supported() && is_thp) { 1647124abcedSHuang Ying nr_failed++; 16486f7d760eSHuang Ying stats->nr_thp_failed++; 1649a21d2133SHuang Ying if (!try_split_folio(folio, split_folios)) { 16506f7d760eSHuang Ying stats->nr_thp_split++; 16516f7d760eSHuang Ying continue; 16526f7d760eSHuang Ying } 16536f7d760eSHuang Ying stats->nr_failed_pages += nr_pages; 16546f7d760eSHuang Ying list_move_tail(&folio->lru, ret_folios); 16556f7d760eSHuang Ying continue; 16566f7d760eSHuang Ying } 16576f7d760eSHuang Ying 16584e096ae1SMatthew Wilcox (Oracle) rc = migrate_folio_unmap(get_new_folio, put_new_folio, 16594e096ae1SMatthew Wilcox (Oracle) private, folio, &dst, mode, reason, 16604e096ae1SMatthew Wilcox (Oracle) ret_folios); 166142012e04SHuang Ying /* 166242012e04SHuang Ying * The rules are: 166342012e04SHuang Ying * Success: folio will be freed 16645dfab109SHuang Ying * Unmap: folio will be put on unmap_folios list, 16655dfab109SHuang Ying * dst folio put on dst_folios list 166642012e04SHuang Ying * -EAGAIN: stay on the from list 166742012e04SHuang Ying * -ENOMEM: stay on the from list 166842012e04SHuang Ying * Other errno: put on ret_folios list 166942012e04SHuang Ying */ 167042012e04SHuang Ying switch(rc) { 167142012e04SHuang Ying case -ENOMEM: 167242012e04SHuang Ying /* 167342012e04SHuang Ying * When memory is low, don't bother to try to migrate 16745dfab109SHuang Ying * other folios, move unmapped folios, then exit. 167542012e04SHuang Ying */ 1676124abcedSHuang Ying nr_failed++; 167742012e04SHuang Ying stats->nr_thp_failed += is_thp; 167842012e04SHuang Ying /* Large folio NUMA faulting doesn't split to retry. */ 1679124abcedSHuang Ying if (folio_test_large(folio) && !nosplit) { 1680a21d2133SHuang Ying int ret = try_split_folio(folio, split_folios); 168142012e04SHuang Ying 168242012e04SHuang Ying if (!ret) { 168342012e04SHuang Ying stats->nr_thp_split += is_thp; 168442012e04SHuang Ying break; 168542012e04SHuang Ying } else if (reason == MR_LONGTERM_PIN && 168642012e04SHuang Ying ret == -EAGAIN) { 168742012e04SHuang Ying /* 168842012e04SHuang Ying * Try again to split large folio to 168942012e04SHuang Ying * mitigate the failure of longterm pinning. 169042012e04SHuang Ying */ 1691124abcedSHuang Ying retry++; 169242012e04SHuang Ying thp_retry += is_thp; 169342012e04SHuang Ying nr_retry_pages += nr_pages; 1694851ae642SHuang Ying /* Undo duplicated failure counting. */ 1695124abcedSHuang Ying nr_failed--; 1696851ae642SHuang Ying stats->nr_thp_failed -= is_thp; 169742012e04SHuang Ying break; 169842012e04SHuang Ying } 169942012e04SHuang Ying } 170042012e04SHuang Ying 170142012e04SHuang Ying stats->nr_failed_pages += nr_pages + nr_retry_pages; 170242012e04SHuang Ying /* nr_failed isn't updated for not used */ 170342012e04SHuang Ying stats->nr_thp_failed += thp_retry; 17045dfab109SHuang Ying rc_saved = rc; 17055dfab109SHuang Ying if (list_empty(&unmap_folios)) 170642012e04SHuang Ying goto out; 17075dfab109SHuang Ying else 17085dfab109SHuang Ying goto move; 170942012e04SHuang Ying case -EAGAIN: 171042012e04SHuang Ying retry++; 1711124abcedSHuang Ying thp_retry += is_thp; 171242012e04SHuang Ying nr_retry_pages += nr_pages; 171342012e04SHuang Ying break; 171442012e04SHuang Ying case MIGRATEPAGE_SUCCESS: 171542012e04SHuang Ying stats->nr_succeeded += nr_pages; 171642012e04SHuang Ying stats->nr_thp_succeeded += is_thp; 171742012e04SHuang Ying break; 17185dfab109SHuang Ying case MIGRATEPAGE_UNMAP: 17195dfab109SHuang Ying list_move_tail(&folio->lru, &unmap_folios); 17205dfab109SHuang Ying list_add_tail(&dst->lru, &dst_folios); 17215dfab109SHuang Ying break; 172242012e04SHuang Ying default: 172342012e04SHuang Ying /* 172442012e04SHuang Ying * Permanent failure (-EBUSY, etc.): 172542012e04SHuang Ying * unlike -EAGAIN case, the failed folio is 172642012e04SHuang Ying * removed from migration folio list and not 172742012e04SHuang Ying * retried in the next outer loop. 172842012e04SHuang Ying */ 172942012e04SHuang Ying nr_failed++; 1730124abcedSHuang Ying stats->nr_thp_failed += is_thp; 173142012e04SHuang Ying stats->nr_failed_pages += nr_pages; 173242012e04SHuang Ying break; 173342012e04SHuang Ying } 173442012e04SHuang Ying } 173542012e04SHuang Ying } 173642012e04SHuang Ying nr_failed += retry; 173742012e04SHuang Ying stats->nr_thp_failed += thp_retry; 173842012e04SHuang Ying stats->nr_failed_pages += nr_retry_pages; 17395dfab109SHuang Ying move: 17407e12beb8SHuang Ying /* Flush TLBs for all unmapped folios */ 17417e12beb8SHuang Ying try_to_unmap_flush(); 17427e12beb8SHuang Ying 17435dfab109SHuang Ying retry = 1; 1744124abcedSHuang Ying for (pass = 0; pass < nr_pass && retry; pass++) { 17455dfab109SHuang Ying retry = 0; 17465dfab109SHuang Ying thp_retry = 0; 17475dfab109SHuang Ying nr_retry_pages = 0; 17485dfab109SHuang Ying 17495dfab109SHuang Ying dst = list_first_entry(&dst_folios, struct folio, lru); 17505dfab109SHuang Ying dst2 = list_next_entry(dst, lru); 17515dfab109SHuang Ying list_for_each_entry_safe(folio, folio2, &unmap_folios, lru) { 1752124abcedSHuang Ying is_thp = folio_test_large(folio) && folio_test_pmd_mappable(folio); 17535dfab109SHuang Ying nr_pages = folio_nr_pages(folio); 17545dfab109SHuang Ying 17555dfab109SHuang Ying cond_resched(); 17565dfab109SHuang Ying 17574e096ae1SMatthew Wilcox (Oracle) rc = migrate_folio_move(put_new_folio, private, 17585dfab109SHuang Ying folio, dst, mode, 17595dfab109SHuang Ying reason, ret_folios); 17605dfab109SHuang Ying /* 17615dfab109SHuang Ying * The rules are: 17625dfab109SHuang Ying * Success: folio will be freed 17635dfab109SHuang Ying * -EAGAIN: stay on the unmap_folios list 17645dfab109SHuang Ying * Other errno: put on ret_folios list 17655dfab109SHuang Ying */ 17665dfab109SHuang Ying switch(rc) { 17675dfab109SHuang Ying case -EAGAIN: 17685dfab109SHuang Ying retry++; 1769124abcedSHuang Ying thp_retry += is_thp; 17705dfab109SHuang Ying nr_retry_pages += nr_pages; 17715dfab109SHuang Ying break; 17725dfab109SHuang Ying case MIGRATEPAGE_SUCCESS: 17735dfab109SHuang Ying stats->nr_succeeded += nr_pages; 17745dfab109SHuang Ying stats->nr_thp_succeeded += is_thp; 17755dfab109SHuang Ying break; 17765dfab109SHuang Ying default: 17775dfab109SHuang Ying nr_failed++; 1778124abcedSHuang Ying stats->nr_thp_failed += is_thp; 17795dfab109SHuang Ying stats->nr_failed_pages += nr_pages; 17805dfab109SHuang Ying break; 17815dfab109SHuang Ying } 17825dfab109SHuang Ying dst = dst2; 17835dfab109SHuang Ying dst2 = list_next_entry(dst, lru); 17845dfab109SHuang Ying } 17855dfab109SHuang Ying } 17865dfab109SHuang Ying nr_failed += retry; 17875dfab109SHuang Ying stats->nr_thp_failed += thp_retry; 17885dfab109SHuang Ying stats->nr_failed_pages += nr_retry_pages; 17895dfab109SHuang Ying 1790124abcedSHuang Ying rc = rc_saved ? : nr_failed; 17915dfab109SHuang Ying out: 17925dfab109SHuang Ying /* Cleanup remaining folios */ 17935dfab109SHuang Ying dst = list_first_entry(&dst_folios, struct folio, lru); 17945dfab109SHuang Ying dst2 = list_next_entry(dst, lru); 17955dfab109SHuang Ying list_for_each_entry_safe(folio, folio2, &unmap_folios, lru) { 17965dfab109SHuang Ying int page_was_mapped = 0; 17975dfab109SHuang Ying struct anon_vma *anon_vma = NULL; 17985dfab109SHuang Ying 17995dfab109SHuang Ying __migrate_folio_extract(dst, &page_was_mapped, &anon_vma); 18005dfab109SHuang Ying migrate_folio_undo_src(folio, page_was_mapped, anon_vma, 1801ebe75e47SHuang Ying true, ret_folios); 18025dfab109SHuang Ying list_del(&dst->lru); 18034e096ae1SMatthew Wilcox (Oracle) migrate_folio_undo_dst(dst, true, put_new_folio, private); 18045dfab109SHuang Ying dst = dst2; 18055dfab109SHuang Ying dst2 = list_next_entry(dst, lru); 18065dfab109SHuang Ying } 18075dfab109SHuang Ying 180842012e04SHuang Ying return rc; 180942012e04SHuang Ying } 181042012e04SHuang Ying 18114e096ae1SMatthew Wilcox (Oracle) static int migrate_pages_sync(struct list_head *from, new_folio_t get_new_folio, 18124e096ae1SMatthew Wilcox (Oracle) free_folio_t put_new_folio, unsigned long private, 18134e096ae1SMatthew Wilcox (Oracle) enum migrate_mode mode, int reason, 18144e096ae1SMatthew Wilcox (Oracle) struct list_head *ret_folios, struct list_head *split_folios, 18154e096ae1SMatthew Wilcox (Oracle) struct migrate_pages_stats *stats) 18162ef7dbb2SHuang Ying { 18172ef7dbb2SHuang Ying int rc, nr_failed = 0; 18182ef7dbb2SHuang Ying LIST_HEAD(folios); 18192ef7dbb2SHuang Ying struct migrate_pages_stats astats; 18202ef7dbb2SHuang Ying 18212ef7dbb2SHuang Ying memset(&astats, 0, sizeof(astats)); 18222ef7dbb2SHuang Ying /* Try to migrate in batch with MIGRATE_ASYNC mode firstly */ 18234e096ae1SMatthew Wilcox (Oracle) rc = migrate_pages_batch(from, get_new_folio, put_new_folio, private, MIGRATE_ASYNC, 18242ef7dbb2SHuang Ying reason, &folios, split_folios, &astats, 18252ef7dbb2SHuang Ying NR_MAX_MIGRATE_ASYNC_RETRY); 18262ef7dbb2SHuang Ying stats->nr_succeeded += astats.nr_succeeded; 18272ef7dbb2SHuang Ying stats->nr_thp_succeeded += astats.nr_thp_succeeded; 18282ef7dbb2SHuang Ying stats->nr_thp_split += astats.nr_thp_split; 18292ef7dbb2SHuang Ying if (rc < 0) { 18302ef7dbb2SHuang Ying stats->nr_failed_pages += astats.nr_failed_pages; 18312ef7dbb2SHuang Ying stats->nr_thp_failed += astats.nr_thp_failed; 18322ef7dbb2SHuang Ying list_splice_tail(&folios, ret_folios); 18332ef7dbb2SHuang Ying return rc; 18342ef7dbb2SHuang Ying } 18352ef7dbb2SHuang Ying stats->nr_thp_failed += astats.nr_thp_split; 18362ef7dbb2SHuang Ying nr_failed += astats.nr_thp_split; 18372ef7dbb2SHuang Ying /* 18382ef7dbb2SHuang Ying * Fall back to migrate all failed folios one by one synchronously. All 18392ef7dbb2SHuang Ying * failed folios except split THPs will be retried, so their failure 18402ef7dbb2SHuang Ying * isn't counted 18412ef7dbb2SHuang Ying */ 18422ef7dbb2SHuang Ying list_splice_tail_init(&folios, from); 18432ef7dbb2SHuang Ying while (!list_empty(from)) { 18442ef7dbb2SHuang Ying list_move(from->next, &folios); 18454e096ae1SMatthew Wilcox (Oracle) rc = migrate_pages_batch(&folios, get_new_folio, put_new_folio, 18462ef7dbb2SHuang Ying private, mode, reason, ret_folios, 18472ef7dbb2SHuang Ying split_folios, stats, NR_MAX_MIGRATE_SYNC_RETRY); 18482ef7dbb2SHuang Ying list_splice_tail_init(&folios, ret_folios); 18492ef7dbb2SHuang Ying if (rc < 0) 18502ef7dbb2SHuang Ying return rc; 18512ef7dbb2SHuang Ying nr_failed += rc; 18522ef7dbb2SHuang Ying } 18532ef7dbb2SHuang Ying 18542ef7dbb2SHuang Ying return nr_failed; 18552ef7dbb2SHuang Ying } 18562ef7dbb2SHuang Ying 1857e24f0b8fSChristoph Lameter /* 1858eaec4e63SHuang Ying * migrate_pages - migrate the folios specified in a list, to the free folios 1859c73e5c9cSSrivatsa S. Bhat * supplied as the target for the page migration 1860e24f0b8fSChristoph Lameter * 1861eaec4e63SHuang Ying * @from: The list of folios to be migrated. 18624e096ae1SMatthew Wilcox (Oracle) * @get_new_folio: The function used to allocate free folios to be used 1863eaec4e63SHuang Ying * as the target of the folio migration. 18644e096ae1SMatthew Wilcox (Oracle) * @put_new_folio: The function used to free target folios if migration 186568711a74SDavid Rientjes * fails, or NULL if no special handling is necessary. 18664e096ae1SMatthew Wilcox (Oracle) * @private: Private data to be passed on to get_new_folio() 1867c73e5c9cSSrivatsa S. Bhat * @mode: The migration mode that specifies the constraints for 1868eaec4e63SHuang Ying * folio migration, if any. 1869eaec4e63SHuang Ying * @reason: The reason for folio migration. 1870eaec4e63SHuang Ying * @ret_succeeded: Set to the number of folios migrated successfully if 18715ac95884SYang Shi * the caller passes a non-NULL pointer. 1872e24f0b8fSChristoph Lameter * 1873e5bfff8bSHuang Ying * The function returns after NR_MAX_MIGRATE_PAGES_RETRY attempts or if no folios 1874e5bfff8bSHuang Ying * are movable any more because the list has become empty or no retryable folios 1875e5bfff8bSHuang Ying * exist any more. It is caller's responsibility to call putback_movable_pages() 1876e5bfff8bSHuang Ying * only if ret != 0. 1877e24f0b8fSChristoph Lameter * 1878eaec4e63SHuang Ying * Returns the number of {normal folio, large folio, hugetlb} that were not 1879eaec4e63SHuang Ying * migrated, or an error code. The number of large folio splits will be 1880eaec4e63SHuang Ying * considered as the number of non-migrated large folio, no matter how many 1881eaec4e63SHuang Ying * split folios of the large folio are migrated successfully. 1882e24f0b8fSChristoph Lameter */ 18834e096ae1SMatthew Wilcox (Oracle) int migrate_pages(struct list_head *from, new_folio_t get_new_folio, 18844e096ae1SMatthew Wilcox (Oracle) free_folio_t put_new_folio, unsigned long private, 18855ac95884SYang Shi enum migrate_mode mode, int reason, unsigned int *ret_succeeded) 1886e24f0b8fSChristoph Lameter { 188742012e04SHuang Ying int rc, rc_gather; 18882ef7dbb2SHuang Ying int nr_pages; 1889eaec4e63SHuang Ying struct folio *folio, *folio2; 189042012e04SHuang Ying LIST_HEAD(folios); 1891eaec4e63SHuang Ying LIST_HEAD(ret_folios); 1892a21d2133SHuang Ying LIST_HEAD(split_folios); 18935b855937SHuang Ying struct migrate_pages_stats stats; 18942d1db3b1SChristoph Lameter 18957bc1aec5SLiam Mark trace_mm_migrate_pages_start(mode, reason); 18967bc1aec5SLiam Mark 18975b855937SHuang Ying memset(&stats, 0, sizeof(stats)); 1898e24f0b8fSChristoph Lameter 18994e096ae1SMatthew Wilcox (Oracle) rc_gather = migrate_hugetlbs(from, get_new_folio, put_new_folio, private, 190042012e04SHuang Ying mode, reason, &stats, &ret_folios); 190142012e04SHuang Ying if (rc_gather < 0) 190295a402c3SChristoph Lameter goto out; 1903fb3592c4SHuang Ying 190442012e04SHuang Ying again: 190542012e04SHuang Ying nr_pages = 0; 1906b20a3503SChristoph Lameter list_for_each_entry_safe(folio, folio2, from, lru) { 1907e5bfff8bSHuang Ying /* Retried hugetlb folios will be kept in list */ 1908e5bfff8bSHuang Ying if (folio_test_hugetlb(folio)) { 1909e5bfff8bSHuang Ying list_move_tail(&folio->lru, &ret_folios); 1910e5bfff8bSHuang Ying continue; 1911eaec4e63SHuang Ying } 1912f430893bSMiaohe Lin 191342012e04SHuang Ying nr_pages += folio_nr_pages(folio); 19142ef7dbb2SHuang Ying if (nr_pages >= NR_MAX_BATCHED_MIGRATION) 1915e24f0b8fSChristoph Lameter break; 1916b20a3503SChristoph Lameter } 19172ef7dbb2SHuang Ying if (nr_pages >= NR_MAX_BATCHED_MIGRATION) 1918fb3592c4SHuang Ying list_cut_before(&folios, from, &folio2->lru); 191942012e04SHuang Ying else 192042012e04SHuang Ying list_splice_init(from, &folios); 19212ef7dbb2SHuang Ying if (mode == MIGRATE_ASYNC) 19224e096ae1SMatthew Wilcox (Oracle) rc = migrate_pages_batch(&folios, get_new_folio, put_new_folio, 19234e096ae1SMatthew Wilcox (Oracle) private, mode, reason, &ret_folios, 19244e096ae1SMatthew Wilcox (Oracle) &split_folios, &stats, 1925a21d2133SHuang Ying NR_MAX_MIGRATE_PAGES_RETRY); 19262ef7dbb2SHuang Ying else 19274e096ae1SMatthew Wilcox (Oracle) rc = migrate_pages_sync(&folios, get_new_folio, put_new_folio, 19284e096ae1SMatthew Wilcox (Oracle) private, mode, reason, &ret_folios, 19294e096ae1SMatthew Wilcox (Oracle) &split_folios, &stats); 193042012e04SHuang Ying list_splice_tail_init(&folios, &ret_folios); 193142012e04SHuang Ying if (rc < 0) { 193242012e04SHuang Ying rc_gather = rc; 1933a21d2133SHuang Ying list_splice_tail(&split_folios, &ret_folios); 1934b20a3503SChristoph Lameter goto out; 1935b20a3503SChristoph Lameter } 1936a21d2133SHuang Ying if (!list_empty(&split_folios)) { 1937a21d2133SHuang Ying /* 1938a21d2133SHuang Ying * Failure isn't counted since all split folios of a large folio 1939a21d2133SHuang Ying * is counted as 1 failure already. And, we only try to migrate 1940a21d2133SHuang Ying * with minimal effort, force MIGRATE_ASYNC mode and retry once. 1941a21d2133SHuang Ying */ 19424e096ae1SMatthew Wilcox (Oracle) migrate_pages_batch(&split_folios, get_new_folio, 19434e096ae1SMatthew Wilcox (Oracle) put_new_folio, private, MIGRATE_ASYNC, reason, 19444e096ae1SMatthew Wilcox (Oracle) &ret_folios, NULL, &stats, 1); 1945a21d2133SHuang Ying list_splice_tail_init(&split_folios, &ret_folios); 1946a21d2133SHuang Ying } 194742012e04SHuang Ying rc_gather += rc; 194842012e04SHuang Ying if (!list_empty(from)) 194942012e04SHuang Ying goto again; 195095a402c3SChristoph Lameter out: 1951dd4ae78aSYang Shi /* 1952eaec4e63SHuang Ying * Put the permanent failure folio back to migration list, they 1953dd4ae78aSYang Shi * will be put back to the right list by the caller. 1954dd4ae78aSYang Shi */ 1955eaec4e63SHuang Ying list_splice(&ret_folios, from); 1956dd4ae78aSYang Shi 195703e5f82eSBaolin Wang /* 1958eaec4e63SHuang Ying * Return 0 in case all split folios of fail-to-migrate large folios 1959eaec4e63SHuang Ying * are migrated successfully. 196003e5f82eSBaolin Wang */ 196103e5f82eSBaolin Wang if (list_empty(from)) 196242012e04SHuang Ying rc_gather = 0; 196303e5f82eSBaolin Wang 19645b855937SHuang Ying count_vm_events(PGMIGRATE_SUCCESS, stats.nr_succeeded); 19655b855937SHuang Ying count_vm_events(PGMIGRATE_FAIL, stats.nr_failed_pages); 19665b855937SHuang Ying count_vm_events(THP_MIGRATION_SUCCESS, stats.nr_thp_succeeded); 19675b855937SHuang Ying count_vm_events(THP_MIGRATION_FAIL, stats.nr_thp_failed); 19685b855937SHuang Ying count_vm_events(THP_MIGRATION_SPLIT, stats.nr_thp_split); 19695b855937SHuang Ying trace_mm_migrate_pages(stats.nr_succeeded, stats.nr_failed_pages, 19705b855937SHuang Ying stats.nr_thp_succeeded, stats.nr_thp_failed, 19715b855937SHuang Ying stats.nr_thp_split, mode, reason); 19727b2a2d4aSMel Gorman 19735ac95884SYang Shi if (ret_succeeded) 19745b855937SHuang Ying *ret_succeeded = stats.nr_succeeded; 19755ac95884SYang Shi 197642012e04SHuang Ying return rc_gather; 1977b20a3503SChristoph Lameter } 1978b20a3503SChristoph Lameter 19794e096ae1SMatthew Wilcox (Oracle) struct folio *alloc_migration_target(struct folio *src, unsigned long private) 1980b4b38223SJoonsoo Kim { 198119fc7bedSJoonsoo Kim struct migration_target_control *mtc; 198219fc7bedSJoonsoo Kim gfp_t gfp_mask; 1983b4b38223SJoonsoo Kim unsigned int order = 0; 198419fc7bedSJoonsoo Kim int nid; 198519fc7bedSJoonsoo Kim int zidx; 198619fc7bedSJoonsoo Kim 198719fc7bedSJoonsoo Kim mtc = (struct migration_target_control *)private; 198819fc7bedSJoonsoo Kim gfp_mask = mtc->gfp_mask; 198919fc7bedSJoonsoo Kim nid = mtc->nid; 199019fc7bedSJoonsoo Kim if (nid == NUMA_NO_NODE) 19914e096ae1SMatthew Wilcox (Oracle) nid = folio_nid(src); 1992b4b38223SJoonsoo Kim 19934e096ae1SMatthew Wilcox (Oracle) if (folio_test_hugetlb(src)) { 19944e096ae1SMatthew Wilcox (Oracle) struct hstate *h = folio_hstate(src); 1995d92bbc27SJoonsoo Kim 199619fc7bedSJoonsoo Kim gfp_mask = htlb_modify_alloc_mask(h, gfp_mask); 19974e096ae1SMatthew Wilcox (Oracle) return alloc_hugetlb_folio_nodemask(h, nid, 1998e37d3e83SSidhartha Kumar mtc->nmask, gfp_mask); 1999d92bbc27SJoonsoo Kim } 2000b4b38223SJoonsoo Kim 20014e096ae1SMatthew Wilcox (Oracle) if (folio_test_large(src)) { 20029933a0c8SJoonsoo Kim /* 20039933a0c8SJoonsoo Kim * clear __GFP_RECLAIM to make the migration callback 20049933a0c8SJoonsoo Kim * consistent with regular THP allocations. 20059933a0c8SJoonsoo Kim */ 20069933a0c8SJoonsoo Kim gfp_mask &= ~__GFP_RECLAIM; 2007b4b38223SJoonsoo Kim gfp_mask |= GFP_TRANSHUGE; 20084e096ae1SMatthew Wilcox (Oracle) order = folio_order(src); 2009b4b38223SJoonsoo Kim } 20104e096ae1SMatthew Wilcox (Oracle) zidx = zone_idx(folio_zone(src)); 201119fc7bedSJoonsoo Kim if (is_highmem_idx(zidx) || zidx == ZONE_MOVABLE) 2012b4b38223SJoonsoo Kim gfp_mask |= __GFP_HIGHMEM; 2013b4b38223SJoonsoo Kim 20144e096ae1SMatthew Wilcox (Oracle) return __folio_alloc(gfp_mask, order, nid, mtc->nmask); 2015b4b38223SJoonsoo Kim } 2016b4b38223SJoonsoo Kim 2017742755a1SChristoph Lameter #ifdef CONFIG_NUMA 2018742755a1SChristoph Lameter 2019a49bd4d7SMichal Hocko static int store_status(int __user *status, int start, int value, int nr) 2020742755a1SChristoph Lameter { 2021a49bd4d7SMichal Hocko while (nr-- > 0) { 2022a49bd4d7SMichal Hocko if (put_user(value, status + start)) 2023a49bd4d7SMichal Hocko return -EFAULT; 2024a49bd4d7SMichal Hocko start++; 2025a49bd4d7SMichal Hocko } 2026742755a1SChristoph Lameter 2027a49bd4d7SMichal Hocko return 0; 2028a49bd4d7SMichal Hocko } 2029742755a1SChristoph Lameter 2030a49bd4d7SMichal Hocko static int do_move_pages_to_node(struct mm_struct *mm, 2031a49bd4d7SMichal Hocko struct list_head *pagelist, int node) 2032a49bd4d7SMichal Hocko { 2033a49bd4d7SMichal Hocko int err; 2034a0976311SJoonsoo Kim struct migration_target_control mtc = { 2035a0976311SJoonsoo Kim .nid = node, 2036a0976311SJoonsoo Kim .gfp_mask = GFP_HIGHUSER_MOVABLE | __GFP_THISNODE, 2037a0976311SJoonsoo Kim }; 2038742755a1SChristoph Lameter 2039a0976311SJoonsoo Kim err = migrate_pages(pagelist, alloc_migration_target, NULL, 20405ac95884SYang Shi (unsigned long)&mtc, MIGRATE_SYNC, MR_SYSCALL, NULL); 2041a49bd4d7SMichal Hocko if (err) 2042a49bd4d7SMichal Hocko putback_movable_pages(pagelist); 2043a49bd4d7SMichal Hocko return err; 2044742755a1SChristoph Lameter } 2045742755a1SChristoph Lameter 2046742755a1SChristoph Lameter /* 2047a49bd4d7SMichal Hocko * Resolves the given address to a struct page, isolates it from the LRU and 2048a49bd4d7SMichal Hocko * puts it to the given pagelist. 2049e0153fc2SYang Shi * Returns: 2050e0153fc2SYang Shi * errno - if the page cannot be found/isolated 2051e0153fc2SYang Shi * 0 - when it doesn't have to be migrated because it is already on the 2052e0153fc2SYang Shi * target node 2053e0153fc2SYang Shi * 1 - when it has been queued 2054742755a1SChristoph Lameter */ 2055428e106aSKirill A. Shutemov static int add_page_for_migration(struct mm_struct *mm, const void __user *p, 2056a49bd4d7SMichal Hocko int node, struct list_head *pagelist, bool migrate_all) 2057742755a1SChristoph Lameter { 2058742755a1SChristoph Lameter struct vm_area_struct *vma; 2059428e106aSKirill A. Shutemov unsigned long addr; 2060742755a1SChristoph Lameter struct page *page; 2061a49bd4d7SMichal Hocko int err; 20629747b9e9SBaolin Wang bool isolated; 2063742755a1SChristoph Lameter 2064d8ed45c5SMichel Lespinasse mmap_read_lock(mm); 2065428e106aSKirill A. Shutemov addr = (unsigned long)untagged_addr_remote(mm, p); 2066428e106aSKirill A. Shutemov 2067742755a1SChristoph Lameter err = -EFAULT; 2068cb1c37b1SMiaohe Lin vma = vma_lookup(mm, addr); 2069cb1c37b1SMiaohe Lin if (!vma || !vma_migratable(vma)) 2070a49bd4d7SMichal Hocko goto out; 2071742755a1SChristoph Lameter 2072d899844eSKirill A. Shutemov /* FOLL_DUMP to ignore special (like zero) pages */ 207387d2762eSMiaohe Lin page = follow_page(vma, addr, FOLL_GET | FOLL_DUMP); 207489f5b7daSLinus Torvalds 207589f5b7daSLinus Torvalds err = PTR_ERR(page); 207689f5b7daSLinus Torvalds if (IS_ERR(page)) 2077a49bd4d7SMichal Hocko goto out; 207889f5b7daSLinus Torvalds 2079742755a1SChristoph Lameter err = -ENOENT; 2080f7091ed6SHaiyue Wang if (!page) 2081a49bd4d7SMichal Hocko goto out; 2082742755a1SChristoph Lameter 2083f7091ed6SHaiyue Wang if (is_zone_device_page(page)) 2084f7091ed6SHaiyue Wang goto out_putpage; 2085f7091ed6SHaiyue Wang 2086a49bd4d7SMichal Hocko err = 0; 2087a49bd4d7SMichal Hocko if (page_to_nid(page) == node) 2088a49bd4d7SMichal Hocko goto out_putpage; 2089742755a1SChristoph Lameter 2090742755a1SChristoph Lameter err = -EACCES; 2091a49bd4d7SMichal Hocko if (page_mapcount(page) > 1 && !migrate_all) 2092a49bd4d7SMichal Hocko goto out_putpage; 2093742755a1SChristoph Lameter 2094e632a938SNaoya Horiguchi if (PageHuge(page)) { 2095e8db67ebSNaoya Horiguchi if (PageHead(page)) { 20969747b9e9SBaolin Wang isolated = isolate_hugetlb(page_folio(page), pagelist); 20979747b9e9SBaolin Wang err = isolated ? 1 : -EBUSY; 2098e8db67ebSNaoya Horiguchi } 2099a49bd4d7SMichal Hocko } else { 2100a49bd4d7SMichal Hocko struct page *head; 2101e632a938SNaoya Horiguchi 2102e8db67ebSNaoya Horiguchi head = compound_head(page); 2103f7f9c00dSBaolin Wang isolated = isolate_lru_page(head); 2104f7f9c00dSBaolin Wang if (!isolated) { 2105f7f9c00dSBaolin Wang err = -EBUSY; 2106a49bd4d7SMichal Hocko goto out_putpage; 2107f7f9c00dSBaolin Wang } 2108a49bd4d7SMichal Hocko 2109e0153fc2SYang Shi err = 1; 2110a49bd4d7SMichal Hocko list_add_tail(&head->lru, pagelist); 2111e8db67ebSNaoya Horiguchi mod_node_page_state(page_pgdat(head), 21129de4f22aSHuang Ying NR_ISOLATED_ANON + page_is_file_lru(head), 21136c357848SMatthew Wilcox (Oracle) thp_nr_pages(head)); 21146d9c285aSKOSAKI Motohiro } 2115a49bd4d7SMichal Hocko out_putpage: 2116742755a1SChristoph Lameter /* 2117742755a1SChristoph Lameter * Either remove the duplicate refcount from 2118742755a1SChristoph Lameter * isolate_lru_page() or drop the page ref if it was 2119742755a1SChristoph Lameter * not isolated. 2120742755a1SChristoph Lameter */ 2121742755a1SChristoph Lameter put_page(page); 2122a49bd4d7SMichal Hocko out: 2123d8ed45c5SMichel Lespinasse mmap_read_unlock(mm); 2124742755a1SChristoph Lameter return err; 2125742755a1SChristoph Lameter } 2126742755a1SChristoph Lameter 21277ca8783aSWei Yang static int move_pages_and_store_status(struct mm_struct *mm, int node, 21287ca8783aSWei Yang struct list_head *pagelist, int __user *status, 21297ca8783aSWei Yang int start, int i, unsigned long nr_pages) 21307ca8783aSWei Yang { 21317ca8783aSWei Yang int err; 21327ca8783aSWei Yang 21335d7ae891SWei Yang if (list_empty(pagelist)) 21345d7ae891SWei Yang return 0; 21355d7ae891SWei Yang 21367ca8783aSWei Yang err = do_move_pages_to_node(mm, pagelist, node); 21377ca8783aSWei Yang if (err) { 21387ca8783aSWei Yang /* 21397ca8783aSWei Yang * Positive err means the number of failed 21407ca8783aSWei Yang * pages to migrate. Since we are going to 21417ca8783aSWei Yang * abort and return the number of non-migrated 2142ab9dd4f8SLong Li * pages, so need to include the rest of the 21437ca8783aSWei Yang * nr_pages that have not been attempted as 21447ca8783aSWei Yang * well. 21457ca8783aSWei Yang */ 21467ca8783aSWei Yang if (err > 0) 2147a7504ed1SHuang Ying err += nr_pages - i; 21487ca8783aSWei Yang return err; 21497ca8783aSWei Yang } 21507ca8783aSWei Yang return store_status(status, start, node, i - start); 21517ca8783aSWei Yang } 21527ca8783aSWei Yang 2153742755a1SChristoph Lameter /* 21545e9a0f02SBrice Goglin * Migrate an array of page address onto an array of nodes and fill 21555e9a0f02SBrice Goglin * the corresponding array of status. 21565e9a0f02SBrice Goglin */ 21573268c63eSChristoph Lameter static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes, 21585e9a0f02SBrice Goglin unsigned long nr_pages, 21595e9a0f02SBrice Goglin const void __user * __user *pages, 21605e9a0f02SBrice Goglin const int __user *nodes, 21615e9a0f02SBrice Goglin int __user *status, int flags) 21625e9a0f02SBrice Goglin { 2163a49bd4d7SMichal Hocko int current_node = NUMA_NO_NODE; 2164a49bd4d7SMichal Hocko LIST_HEAD(pagelist); 2165a49bd4d7SMichal Hocko int start, i; 2166a49bd4d7SMichal Hocko int err = 0, err1; 216735282a2dSBrice Goglin 2168361a2a22SMinchan Kim lru_cache_disable(); 216935282a2dSBrice Goglin 2170a49bd4d7SMichal Hocko for (i = start = 0; i < nr_pages; i++) { 21715e9a0f02SBrice Goglin const void __user *p; 21725e9a0f02SBrice Goglin int node; 21735e9a0f02SBrice Goglin 21743140a227SBrice Goglin err = -EFAULT; 2175a49bd4d7SMichal Hocko if (get_user(p, pages + i)) 2176a49bd4d7SMichal Hocko goto out_flush; 2177a49bd4d7SMichal Hocko if (get_user(node, nodes + i)) 2178a49bd4d7SMichal Hocko goto out_flush; 21795e9a0f02SBrice Goglin 21805e9a0f02SBrice Goglin err = -ENODEV; 21816f5a55f1SLinus Torvalds if (node < 0 || node >= MAX_NUMNODES) 2182a49bd4d7SMichal Hocko goto out_flush; 2183389162c2SLai Jiangshan if (!node_state(node, N_MEMORY)) 2184a49bd4d7SMichal Hocko goto out_flush; 21855e9a0f02SBrice Goglin 21865e9a0f02SBrice Goglin err = -EACCES; 21875e9a0f02SBrice Goglin if (!node_isset(node, task_nodes)) 2188a49bd4d7SMichal Hocko goto out_flush; 21895e9a0f02SBrice Goglin 2190a49bd4d7SMichal Hocko if (current_node == NUMA_NO_NODE) { 2191a49bd4d7SMichal Hocko current_node = node; 2192a49bd4d7SMichal Hocko start = i; 2193a49bd4d7SMichal Hocko } else if (node != current_node) { 21947ca8783aSWei Yang err = move_pages_and_store_status(mm, current_node, 21957ca8783aSWei Yang &pagelist, status, start, i, nr_pages); 2196a49bd4d7SMichal Hocko if (err) 2197a49bd4d7SMichal Hocko goto out; 2198a49bd4d7SMichal Hocko start = i; 2199a49bd4d7SMichal Hocko current_node = node; 22005e9a0f02SBrice Goglin } 22015e9a0f02SBrice Goglin 2202a49bd4d7SMichal Hocko /* 2203a49bd4d7SMichal Hocko * Errors in the page lookup or isolation are not fatal and we simply 2204a49bd4d7SMichal Hocko * report them via status 2205a49bd4d7SMichal Hocko */ 2206428e106aSKirill A. Shutemov err = add_page_for_migration(mm, p, current_node, &pagelist, 2207428e106aSKirill A. Shutemov flags & MPOL_MF_MOVE_ALL); 2208e0153fc2SYang Shi 2209d08221a0SWei Yang if (err > 0) { 2210e0153fc2SYang Shi /* The page is successfully queued for migration */ 2211e0153fc2SYang Shi continue; 2212e0153fc2SYang Shi } 22133140a227SBrice Goglin 2214d08221a0SWei Yang /* 221565462462SJohn Hubbard * The move_pages() man page does not have an -EEXIST choice, so 221665462462SJohn Hubbard * use -EFAULT instead. 221765462462SJohn Hubbard */ 221865462462SJohn Hubbard if (err == -EEXIST) 221965462462SJohn Hubbard err = -EFAULT; 222065462462SJohn Hubbard 222165462462SJohn Hubbard /* 2222d08221a0SWei Yang * If the page is already on the target node (!err), store the 2223d08221a0SWei Yang * node, otherwise, store the err. 2224d08221a0SWei Yang */ 2225d08221a0SWei Yang err = store_status(status, i, err ? : current_node, 1); 2226a49bd4d7SMichal Hocko if (err) 2227a49bd4d7SMichal Hocko goto out_flush; 22283140a227SBrice Goglin 22297ca8783aSWei Yang err = move_pages_and_store_status(mm, current_node, &pagelist, 22307ca8783aSWei Yang status, start, i, nr_pages); 2231a7504ed1SHuang Ying if (err) { 2232a7504ed1SHuang Ying /* We have accounted for page i */ 2233a7504ed1SHuang Ying if (err > 0) 2234a7504ed1SHuang Ying err--; 2235a49bd4d7SMichal Hocko goto out; 2236a7504ed1SHuang Ying } 2237a49bd4d7SMichal Hocko current_node = NUMA_NO_NODE; 22383140a227SBrice Goglin } 2239a49bd4d7SMichal Hocko out_flush: 2240a49bd4d7SMichal Hocko /* Make sure we do not overwrite the existing error */ 22417ca8783aSWei Yang err1 = move_pages_and_store_status(mm, current_node, &pagelist, 22427ca8783aSWei Yang status, start, i, nr_pages); 2243dfe9aa23SWei Yang if (err >= 0) 2244a49bd4d7SMichal Hocko err = err1; 22455e9a0f02SBrice Goglin out: 2246361a2a22SMinchan Kim lru_cache_enable(); 22475e9a0f02SBrice Goglin return err; 22485e9a0f02SBrice Goglin } 22495e9a0f02SBrice Goglin 22505e9a0f02SBrice Goglin /* 22512f007e74SBrice Goglin * Determine the nodes of an array of pages and store it in an array of status. 2252742755a1SChristoph Lameter */ 225380bba129SBrice Goglin static void do_pages_stat_array(struct mm_struct *mm, unsigned long nr_pages, 225480bba129SBrice Goglin const void __user **pages, int *status) 2255742755a1SChristoph Lameter { 22562f007e74SBrice Goglin unsigned long i; 2257742755a1SChristoph Lameter 2258d8ed45c5SMichel Lespinasse mmap_read_lock(mm); 22592f007e74SBrice Goglin 22602f007e74SBrice Goglin for (i = 0; i < nr_pages; i++) { 226180bba129SBrice Goglin unsigned long addr = (unsigned long)(*pages); 22622f007e74SBrice Goglin struct vm_area_struct *vma; 22632f007e74SBrice Goglin struct page *page; 2264c095adbcSKOSAKI Motohiro int err = -EFAULT; 22652f007e74SBrice Goglin 2266059b8b48SLiam Howlett vma = vma_lookup(mm, addr); 2267059b8b48SLiam Howlett if (!vma) 2268742755a1SChristoph Lameter goto set_status; 2269742755a1SChristoph Lameter 2270d899844eSKirill A. Shutemov /* FOLL_DUMP to ignore special (like zero) pages */ 227116fd6b31SBaolin Wang page = follow_page(vma, addr, FOLL_GET | FOLL_DUMP); 227289f5b7daSLinus Torvalds 227389f5b7daSLinus Torvalds err = PTR_ERR(page); 227489f5b7daSLinus Torvalds if (IS_ERR(page)) 227589f5b7daSLinus Torvalds goto set_status; 227689f5b7daSLinus Torvalds 2277f7091ed6SHaiyue Wang err = -ENOENT; 2278f7091ed6SHaiyue Wang if (!page) 2279f7091ed6SHaiyue Wang goto set_status; 2280f7091ed6SHaiyue Wang 2281f7091ed6SHaiyue Wang if (!is_zone_device_page(page)) 22824cd61484SMiaohe Lin err = page_to_nid(page); 2283f7091ed6SHaiyue Wang 22844cd61484SMiaohe Lin put_page(page); 2285742755a1SChristoph Lameter set_status: 228680bba129SBrice Goglin *status = err; 228780bba129SBrice Goglin 228880bba129SBrice Goglin pages++; 228980bba129SBrice Goglin status++; 229080bba129SBrice Goglin } 229180bba129SBrice Goglin 2292d8ed45c5SMichel Lespinasse mmap_read_unlock(mm); 229380bba129SBrice Goglin } 229480bba129SBrice Goglin 22955b1b561bSArnd Bergmann static int get_compat_pages_array(const void __user *chunk_pages[], 22965b1b561bSArnd Bergmann const void __user * __user *pages, 22975b1b561bSArnd Bergmann unsigned long chunk_nr) 22985b1b561bSArnd Bergmann { 22995b1b561bSArnd Bergmann compat_uptr_t __user *pages32 = (compat_uptr_t __user *)pages; 23005b1b561bSArnd Bergmann compat_uptr_t p; 23015b1b561bSArnd Bergmann int i; 23025b1b561bSArnd Bergmann 23035b1b561bSArnd Bergmann for (i = 0; i < chunk_nr; i++) { 23045b1b561bSArnd Bergmann if (get_user(p, pages32 + i)) 23055b1b561bSArnd Bergmann return -EFAULT; 23065b1b561bSArnd Bergmann chunk_pages[i] = compat_ptr(p); 23075b1b561bSArnd Bergmann } 23085b1b561bSArnd Bergmann 23095b1b561bSArnd Bergmann return 0; 23105b1b561bSArnd Bergmann } 23115b1b561bSArnd Bergmann 231280bba129SBrice Goglin /* 231380bba129SBrice Goglin * Determine the nodes of a user array of pages and store it in 231480bba129SBrice Goglin * a user array of status. 231580bba129SBrice Goglin */ 231680bba129SBrice Goglin static int do_pages_stat(struct mm_struct *mm, unsigned long nr_pages, 231780bba129SBrice Goglin const void __user * __user *pages, 231880bba129SBrice Goglin int __user *status) 231980bba129SBrice Goglin { 23203eefb826SMiaohe Lin #define DO_PAGES_STAT_CHUNK_NR 16UL 232180bba129SBrice Goglin const void __user *chunk_pages[DO_PAGES_STAT_CHUNK_NR]; 232280bba129SBrice Goglin int chunk_status[DO_PAGES_STAT_CHUNK_NR]; 232380bba129SBrice Goglin 232487b8d1adSH. Peter Anvin while (nr_pages) { 23253eefb826SMiaohe Lin unsigned long chunk_nr = min(nr_pages, DO_PAGES_STAT_CHUNK_NR); 232687b8d1adSH. Peter Anvin 23275b1b561bSArnd Bergmann if (in_compat_syscall()) { 23285b1b561bSArnd Bergmann if (get_compat_pages_array(chunk_pages, pages, 23295b1b561bSArnd Bergmann chunk_nr)) 233087b8d1adSH. Peter Anvin break; 23315b1b561bSArnd Bergmann } else { 23325b1b561bSArnd Bergmann if (copy_from_user(chunk_pages, pages, 23335b1b561bSArnd Bergmann chunk_nr * sizeof(*chunk_pages))) 23345b1b561bSArnd Bergmann break; 23355b1b561bSArnd Bergmann } 233680bba129SBrice Goglin 233780bba129SBrice Goglin do_pages_stat_array(mm, chunk_nr, chunk_pages, chunk_status); 233880bba129SBrice Goglin 233987b8d1adSH. Peter Anvin if (copy_to_user(status, chunk_status, chunk_nr * sizeof(*status))) 234087b8d1adSH. Peter Anvin break; 2341742755a1SChristoph Lameter 234287b8d1adSH. Peter Anvin pages += chunk_nr; 234387b8d1adSH. Peter Anvin status += chunk_nr; 234487b8d1adSH. Peter Anvin nr_pages -= chunk_nr; 234587b8d1adSH. Peter Anvin } 234687b8d1adSH. Peter Anvin return nr_pages ? -EFAULT : 0; 2347742755a1SChristoph Lameter } 2348742755a1SChristoph Lameter 23494dc200ceSMiaohe Lin static struct mm_struct *find_mm_struct(pid_t pid, nodemask_t *mem_nodes) 23504dc200ceSMiaohe Lin { 23514dc200ceSMiaohe Lin struct task_struct *task; 23524dc200ceSMiaohe Lin struct mm_struct *mm; 23534dc200ceSMiaohe Lin 23544dc200ceSMiaohe Lin /* 23554dc200ceSMiaohe Lin * There is no need to check if current process has the right to modify 23564dc200ceSMiaohe Lin * the specified process when they are same. 23574dc200ceSMiaohe Lin */ 23584dc200ceSMiaohe Lin if (!pid) { 23594dc200ceSMiaohe Lin mmget(current->mm); 23604dc200ceSMiaohe Lin *mem_nodes = cpuset_mems_allowed(current); 23614dc200ceSMiaohe Lin return current->mm; 23624dc200ceSMiaohe Lin } 23634dc200ceSMiaohe Lin 23644dc200ceSMiaohe Lin /* Find the mm_struct */ 23654dc200ceSMiaohe Lin rcu_read_lock(); 23664dc200ceSMiaohe Lin task = find_task_by_vpid(pid); 23674dc200ceSMiaohe Lin if (!task) { 23684dc200ceSMiaohe Lin rcu_read_unlock(); 23694dc200ceSMiaohe Lin return ERR_PTR(-ESRCH); 23704dc200ceSMiaohe Lin } 23714dc200ceSMiaohe Lin get_task_struct(task); 23724dc200ceSMiaohe Lin 23734dc200ceSMiaohe Lin /* 23744dc200ceSMiaohe Lin * Check if this process has the right to modify the specified 23754dc200ceSMiaohe Lin * process. Use the regular "ptrace_may_access()" checks. 23764dc200ceSMiaohe Lin */ 23774dc200ceSMiaohe Lin if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS)) { 23784dc200ceSMiaohe Lin rcu_read_unlock(); 23794dc200ceSMiaohe Lin mm = ERR_PTR(-EPERM); 23804dc200ceSMiaohe Lin goto out; 23814dc200ceSMiaohe Lin } 23824dc200ceSMiaohe Lin rcu_read_unlock(); 23834dc200ceSMiaohe Lin 23844dc200ceSMiaohe Lin mm = ERR_PTR(security_task_movememory(task)); 23854dc200ceSMiaohe Lin if (IS_ERR(mm)) 23864dc200ceSMiaohe Lin goto out; 23874dc200ceSMiaohe Lin *mem_nodes = cpuset_mems_allowed(task); 23884dc200ceSMiaohe Lin mm = get_task_mm(task); 23894dc200ceSMiaohe Lin out: 23904dc200ceSMiaohe Lin put_task_struct(task); 23914dc200ceSMiaohe Lin if (!mm) 23924dc200ceSMiaohe Lin mm = ERR_PTR(-EINVAL); 23934dc200ceSMiaohe Lin return mm; 23944dc200ceSMiaohe Lin } 23954dc200ceSMiaohe Lin 2396742755a1SChristoph Lameter /* 2397742755a1SChristoph Lameter * Move a list of pages in the address space of the currently executing 2398742755a1SChristoph Lameter * process. 2399742755a1SChristoph Lameter */ 24007addf443SDominik Brodowski static int kernel_move_pages(pid_t pid, unsigned long nr_pages, 24017addf443SDominik Brodowski const void __user * __user *pages, 24027addf443SDominik Brodowski const int __user *nodes, 24037addf443SDominik Brodowski int __user *status, int flags) 2404742755a1SChristoph Lameter { 2405742755a1SChristoph Lameter struct mm_struct *mm; 24065e9a0f02SBrice Goglin int err; 24073268c63eSChristoph Lameter nodemask_t task_nodes; 2408742755a1SChristoph Lameter 2409742755a1SChristoph Lameter /* Check flags */ 2410742755a1SChristoph Lameter if (flags & ~(MPOL_MF_MOVE|MPOL_MF_MOVE_ALL)) 2411742755a1SChristoph Lameter return -EINVAL; 2412742755a1SChristoph Lameter 2413742755a1SChristoph Lameter if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE)) 2414742755a1SChristoph Lameter return -EPERM; 2415742755a1SChristoph Lameter 24164dc200ceSMiaohe Lin mm = find_mm_struct(pid, &task_nodes); 24174dc200ceSMiaohe Lin if (IS_ERR(mm)) 24184dc200ceSMiaohe Lin return PTR_ERR(mm); 24196e8b09eaSSasha Levin 24203268c63eSChristoph Lameter if (nodes) 24213268c63eSChristoph Lameter err = do_pages_move(mm, task_nodes, nr_pages, pages, 24223268c63eSChristoph Lameter nodes, status, flags); 24233268c63eSChristoph Lameter else 24245e9a0f02SBrice Goglin err = do_pages_stat(mm, nr_pages, pages, status); 24253268c63eSChristoph Lameter 24263268c63eSChristoph Lameter mmput(mm); 24273268c63eSChristoph Lameter return err; 2428742755a1SChristoph Lameter } 2429742755a1SChristoph Lameter 24307addf443SDominik Brodowski SYSCALL_DEFINE6(move_pages, pid_t, pid, unsigned long, nr_pages, 24317addf443SDominik Brodowski const void __user * __user *, pages, 24327addf443SDominik Brodowski const int __user *, nodes, 24337addf443SDominik Brodowski int __user *, status, int, flags) 24347addf443SDominik Brodowski { 24357addf443SDominik Brodowski return kernel_move_pages(pid, nr_pages, pages, nodes, status, flags); 24367addf443SDominik Brodowski } 24377addf443SDominik Brodowski 24387039e1dbSPeter Zijlstra #ifdef CONFIG_NUMA_BALANCING 24397039e1dbSPeter Zijlstra /* 24407039e1dbSPeter Zijlstra * Returns true if this is a safe migration target node for misplaced NUMA 2441bc53008eSWei Yang * pages. Currently it only checks the watermarks which is crude. 24427039e1dbSPeter Zijlstra */ 24437039e1dbSPeter Zijlstra static bool migrate_balanced_pgdat(struct pglist_data *pgdat, 24443abef4e6SMel Gorman unsigned long nr_migrate_pages) 24457039e1dbSPeter Zijlstra { 24467039e1dbSPeter Zijlstra int z; 2447599d0c95SMel Gorman 24487039e1dbSPeter Zijlstra for (z = pgdat->nr_zones - 1; z >= 0; z--) { 24497039e1dbSPeter Zijlstra struct zone *zone = pgdat->node_zones + z; 24507039e1dbSPeter Zijlstra 2451bc53008eSWei Yang if (!managed_zone(zone)) 24527039e1dbSPeter Zijlstra continue; 24537039e1dbSPeter Zijlstra 24547039e1dbSPeter Zijlstra /* Avoid waking kswapd by allocating pages_to_migrate pages. */ 24557039e1dbSPeter Zijlstra if (!zone_watermark_ok(zone, 0, 24567039e1dbSPeter Zijlstra high_wmark_pages(zone) + 24577039e1dbSPeter Zijlstra nr_migrate_pages, 2458bfe9d006SHuang Ying ZONE_MOVABLE, 0)) 24597039e1dbSPeter Zijlstra continue; 24607039e1dbSPeter Zijlstra return true; 24617039e1dbSPeter Zijlstra } 24627039e1dbSPeter Zijlstra return false; 24637039e1dbSPeter Zijlstra } 24647039e1dbSPeter Zijlstra 24654e096ae1SMatthew Wilcox (Oracle) static struct folio *alloc_misplaced_dst_folio(struct folio *src, 2466666feb21SMichal Hocko unsigned long data) 24677039e1dbSPeter Zijlstra { 24687039e1dbSPeter Zijlstra int nid = (int) data; 24694e096ae1SMatthew Wilcox (Oracle) int order = folio_order(src); 2470c185e494SMatthew Wilcox (Oracle) gfp_t gfp = __GFP_THISNODE; 24717039e1dbSPeter Zijlstra 2472c185e494SMatthew Wilcox (Oracle) if (order > 0) 2473c185e494SMatthew Wilcox (Oracle) gfp |= GFP_TRANSHUGE_LIGHT; 2474c185e494SMatthew Wilcox (Oracle) else { 2475c185e494SMatthew Wilcox (Oracle) gfp |= GFP_HIGHUSER_MOVABLE | __GFP_NOMEMALLOC | __GFP_NORETRY | 2476c185e494SMatthew Wilcox (Oracle) __GFP_NOWARN; 2477c185e494SMatthew Wilcox (Oracle) gfp &= ~__GFP_RECLAIM; 24787039e1dbSPeter Zijlstra } 24794e096ae1SMatthew Wilcox (Oracle) return __folio_alloc_node(gfp, order, nid); 2480c5b5a3ddSYang Shi } 2481c5b5a3ddSYang Shi 24821c30e017SMel Gorman static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page) 2483b32967ffSMel Gorman { 24842b9b624fSBaolin Wang int nr_pages = thp_nr_pages(page); 2485c574bbe9SHuang Ying int order = compound_order(page); 2486b32967ffSMel Gorman 2487c574bbe9SHuang Ying VM_BUG_ON_PAGE(order && !PageTransHuge(page), page); 24883abef4e6SMel Gorman 2489662aeea7SYang Shi /* Do not migrate THP mapped by multiple processes */ 2490662aeea7SYang Shi if (PageTransHuge(page) && total_mapcount(page) > 1) 2491662aeea7SYang Shi return 0; 2492662aeea7SYang Shi 2493b32967ffSMel Gorman /* Avoid migrating to a node that is nearly full */ 2494c574bbe9SHuang Ying if (!migrate_balanced_pgdat(pgdat, nr_pages)) { 2495c574bbe9SHuang Ying int z; 2496c574bbe9SHuang Ying 2497c574bbe9SHuang Ying if (!(sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING)) 2498340ef390SHugh Dickins return 0; 2499c574bbe9SHuang Ying for (z = pgdat->nr_zones - 1; z >= 0; z--) { 2500bc53008eSWei Yang if (managed_zone(pgdat->node_zones + z)) 2501c574bbe9SHuang Ying break; 2502c574bbe9SHuang Ying } 2503c574bbe9SHuang Ying wakeup_kswapd(pgdat->node_zones + z, 0, order, ZONE_MOVABLE); 2504c574bbe9SHuang Ying return 0; 2505c574bbe9SHuang Ying } 2506b32967ffSMel Gorman 2507f7f9c00dSBaolin Wang if (!isolate_lru_page(page)) 2508340ef390SHugh Dickins return 0; 2509340ef390SHugh Dickins 2510b75454e1SMiaohe Lin mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON + page_is_file_lru(page), 25112b9b624fSBaolin Wang nr_pages); 2512b32967ffSMel Gorman 2513b32967ffSMel Gorman /* 2514340ef390SHugh Dickins * Isolating the page has taken another reference, so the 2515340ef390SHugh Dickins * caller's reference can be safely dropped without the page 2516340ef390SHugh Dickins * disappearing underneath us during migration. 2517b32967ffSMel Gorman */ 2518b32967ffSMel Gorman put_page(page); 2519340ef390SHugh Dickins return 1; 2520b32967ffSMel Gorman } 2521b32967ffSMel Gorman 2522a8f60772SMel Gorman /* 25237039e1dbSPeter Zijlstra * Attempt to migrate a misplaced page to the specified destination 25247039e1dbSPeter Zijlstra * node. Caller is expected to have an elevated reference count on 25257039e1dbSPeter Zijlstra * the page that will be dropped by this function before returning. 25267039e1dbSPeter Zijlstra */ 25271bc115d8SMel Gorman int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma, 25281bc115d8SMel Gorman int node) 25297039e1dbSPeter Zijlstra { 2530a8f60772SMel Gorman pg_data_t *pgdat = NODE_DATA(node); 2531340ef390SHugh Dickins int isolated; 2532b32967ffSMel Gorman int nr_remaining; 2533e39bb6beSHuang Ying unsigned int nr_succeeded; 25347039e1dbSPeter Zijlstra LIST_HEAD(migratepages); 2535b5916c02SAneesh Kumar K.V int nr_pages = thp_nr_pages(page); 2536c5b5a3ddSYang Shi 2537c5b5a3ddSYang Shi /* 25381bc115d8SMel Gorman * Don't migrate file pages that are mapped in multiple processes 25391bc115d8SMel Gorman * with execute permissions as they are probably shared libraries. 25407039e1dbSPeter Zijlstra */ 25417ee820eeSMiaohe Lin if (page_mapcount(page) != 1 && page_is_file_lru(page) && 25427ee820eeSMiaohe Lin (vma->vm_flags & VM_EXEC)) 25437039e1dbSPeter Zijlstra goto out; 25447039e1dbSPeter Zijlstra 2545a8f60772SMel Gorman /* 254609a913a7SMel Gorman * Also do not migrate dirty pages as not all filesystems can move 254709a913a7SMel Gorman * dirty pages in MIGRATE_ASYNC mode which is a waste of cycles. 254809a913a7SMel Gorman */ 25499de4f22aSHuang Ying if (page_is_file_lru(page) && PageDirty(page)) 255009a913a7SMel Gorman goto out; 255109a913a7SMel Gorman 2552b32967ffSMel Gorman isolated = numamigrate_isolate_page(pgdat, page); 2553b32967ffSMel Gorman if (!isolated) 25547039e1dbSPeter Zijlstra goto out; 25557039e1dbSPeter Zijlstra 25567039e1dbSPeter Zijlstra list_add(&page->lru, &migratepages); 25574e096ae1SMatthew Wilcox (Oracle) nr_remaining = migrate_pages(&migratepages, alloc_misplaced_dst_folio, 2558c185e494SMatthew Wilcox (Oracle) NULL, node, MIGRATE_ASYNC, 2559c185e494SMatthew Wilcox (Oracle) MR_NUMA_MISPLACED, &nr_succeeded); 25607039e1dbSPeter Zijlstra if (nr_remaining) { 256159c82b70SJoonsoo Kim if (!list_empty(&migratepages)) { 256259c82b70SJoonsoo Kim list_del(&page->lru); 2563c5fc5c3aSYang Shi mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON + 2564c5fc5c3aSYang Shi page_is_file_lru(page), -nr_pages); 256559c82b70SJoonsoo Kim putback_lru_page(page); 256659c82b70SJoonsoo Kim } 25677039e1dbSPeter Zijlstra isolated = 0; 2568e39bb6beSHuang Ying } 2569e39bb6beSHuang Ying if (nr_succeeded) { 2570e39bb6beSHuang Ying count_vm_numa_events(NUMA_PAGE_MIGRATE, nr_succeeded); 2571e39bb6beSHuang Ying if (!node_is_toptier(page_to_nid(page)) && node_is_toptier(node)) 2572e39bb6beSHuang Ying mod_node_page_state(pgdat, PGPROMOTE_SUCCESS, 2573e39bb6beSHuang Ying nr_succeeded); 2574e39bb6beSHuang Ying } 25757039e1dbSPeter Zijlstra BUG_ON(!list_empty(&migratepages)); 25767039e1dbSPeter Zijlstra return isolated; 2577340ef390SHugh Dickins 2578340ef390SHugh Dickins out: 2579340ef390SHugh Dickins put_page(page); 2580340ef390SHugh Dickins return 0; 25817039e1dbSPeter Zijlstra } 2582220018d3SMel Gorman #endif /* CONFIG_NUMA_BALANCING */ 25837d6e2d96SOscar Salvador #endif /* CONFIG_NUMA */ 2584