diff options
Diffstat (limited to 'mm/migrate.c')
| -rw-r--r-- | mm/migrate.c | 183 |
1 files changed, 145 insertions, 38 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index 9c8d5f59d30b..9194375b2307 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -36,6 +36,7 @@ #include <linux/hugetlb_cgroup.h> #include <linux/gfp.h> #include <linux/balloon_compaction.h> +#include <linux/mmu_notifier.h> #include <asm/tlbflush.h> @@ -107,7 +108,7 @@ void putback_movable_pages(struct list_head *l) list_del(&page->lru); dec_zone_page_state(page, NR_ISOLATED_ANON + page_is_file_cache(page)); - if (unlikely(balloon_page_movable(page))) + if (unlikely(isolated_balloon_page(page))) balloon_page_putback(page); else putback_lru_page(page); @@ -130,7 +131,7 @@ static int remove_migration_pte(struct page *new, struct vm_area_struct *vma, ptep = huge_pte_offset(mm, addr); if (!ptep) goto out; - ptl = &mm->page_table_lock; + ptl = huge_pte_lockptr(hstate_vma(vma), mm, ptep); } else { pmd = mm_find_pmd(mm, addr); if (!pmd) @@ -161,6 +162,8 @@ static int remove_migration_pte(struct page *new, struct vm_area_struct *vma, get_page(new); pte = pte_mkold(mk_pte(new, vma->vm_page_prot)); + if (pte_swp_soft_dirty(*ptep)) + pte = pte_mksoft_dirty(pte); if (is_write_migration_entry(entry)) pte = pte_mkwrite(pte); #ifdef CONFIG_HUGETLB_PAGE @@ -247,9 +250,10 @@ void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, __migration_entry_wait(mm, ptep, ptl); } -void migration_entry_wait_huge(struct mm_struct *mm, pte_t *pte) +void migration_entry_wait_huge(struct vm_area_struct *vma, + struct mm_struct *mm, pte_t *pte) { - spinlock_t *ptl = &(mm)->page_table_lock; + spinlock_t *ptl = huge_pte_lockptr(hstate_vma(vma), mm, pte); __migration_entry_wait(mm, pte, ptl); } @@ -313,14 +317,15 @@ static inline bool buffer_migrate_lock_buffers(struct buffer_head *head, */ int migrate_page_move_mapping(struct address_space *mapping, struct page *newpage, struct page *page, - struct buffer_head *head, enum migrate_mode mode) + struct buffer_head *head, enum migrate_mode mode, + int extra_count) { - int expected_count = 0; + int expected_count = 1 + extra_count; void **pslot; if (!mapping) { /* Anonymous page without mapping */ - if (page_count(page) != 1) + if (page_count(page) != expected_count) return -EAGAIN; return MIGRATEPAGE_SUCCESS; } @@ -330,7 +335,7 @@ int migrate_page_move_mapping(struct address_space *mapping, pslot = radix_tree_lookup_slot(&mapping->page_tree, page_index(page)); - expected_count = 2 + page_has_private(page); + expected_count += 1 + page_has_private(page); if (page_count(page) != expected_count || radix_tree_deref_slot_protected(pslot, &mapping->tree_lock) != page) { spin_unlock_irq(&mapping->tree_lock); @@ -439,10 +444,60 @@ int migrate_huge_page_move_mapping(struct address_space *mapping, } /* + * Gigantic pages are so large that we do not guarantee that page++ pointer + * arithmetic will work across the entire page. We need something more + * specialized. + */ +static void __copy_gigantic_page(struct page *dst, struct page *src, + int nr_pages) +{ + int i; + struct page *dst_base = dst; + struct page *src_base = src; + + for (i = 0; i < nr_pages; ) { + cond_resched(); + copy_highpage(dst, src); + + i++; + dst = mem_map_next(dst, dst_base, i); + src = mem_map_next(src, src_base, i); + } +} + +static void copy_huge_page(struct page *dst, struct page *src) +{ + int i; + int nr_pages; + + if (PageHuge(src)) { + /* hugetlbfs page */ + struct hstate *h = page_hstate(src); + nr_pages = pages_per_huge_page(h); + + if (unlikely(nr_pages > MAX_ORDER_NR_PAGES)) { + __copy_gigantic_page(dst, src, nr_pages); + return; + } + } else { + /* thp page */ + BUG_ON(!PageTransHuge(src)); + nr_pages = hpage_nr_pages(src); + } + + for (i = 0; i < nr_pages; i++) { + cond_resched(); + copy_highpage(dst + i, src + i); + } +} + +/* * Copy the page to its new location */ void migrate_page_copy(struct page *newpage, struct page *page) { + int cpupid; + if (PageHuge(page) || PageTransHuge(page)) copy_huge_page(newpage, page); else @@ -479,6 +534,13 @@ void migrate_page_copy(struct page *newpage, struct page *page) __set_page_dirty_nobuffers(newpage); } + /* + * Copy NUMA information to the new page, to prevent over-eager + * future migrations of this same page. + */ + cpupid = page_cpupid_xchg_last(page, -1); + page_cpupid_xchg_last(newpage, cpupid); + mlock_migrate_page(newpage, page); ksm_migrate_page(newpage, page); /* @@ -523,7 +585,7 @@ int migrate_page(struct address_space *mapping, BUG_ON(PageWriteback(page)); /* Writeback must be complete */ - rc = migrate_page_move_mapping(mapping, newpage, page, NULL, mode); + rc = migrate_page_move_mapping(mapping, newpage, page, NULL, mode, 0); if (rc != MIGRATEPAGE_SUCCESS) return rc; @@ -550,7 +612,7 @@ int buffer_migrate_page(struct address_space *mapping, head = page_buffers(page); - rc = migrate_page_move_mapping(mapping, newpage, page, head, mode); + rc = migrate_page_move_mapping(mapping, newpage, page, head, mode, 0); if (rc != MIGRATEPAGE_SUCCESS) return rc; @@ -1498,7 +1560,7 @@ static struct page *alloc_misplaced_dst_page(struct page *page, __GFP_NOWARN) & ~GFP_IOFS, 0); if (newpage) - page_nid_xchg_last(newpage, page_nid_last(page)); + page_cpupid_xchg_last(newpage, page_cpupid_last(page)); return newpage; } @@ -1594,12 +1656,25 @@ int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page) return 1; } +bool pmd_trans_migrating(pmd_t pmd) +{ + struct page *page = pmd_page(pmd); + return PageLocked(page); +} + +void wait_migrate_huge_page(struct anon_vma *anon_vma, pmd_t *pmd) +{ + struct page *page = pmd_page(*pmd); + wait_on_page_locked(page); +} + /* * Attempt to migrate a misplaced page to the specified destination * node. Caller is expected to have an elevated reference count on * the page that will be dropped by this function before returning. */ -int migrate_misplaced_page(struct page *page, int node) +int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma, + int node) { pg_data_t *pgdat = NODE_DATA(node); int isolated; @@ -1607,10 +1682,11 @@ int migrate_misplaced_page(struct page *page, int node) LIST_HEAD(migratepages); /* - * Don't migrate pages that are mapped in multiple processes. - * TODO: Handle false sharing detection instead of this hammer + * Don't migrate file pages that are mapped in multiple processes + * with execute permissions as they are probably shared libraries. */ - if (page_mapcount(page) != 1) + if (page_mapcount(page) != 1 && page_is_file_cache(page) && + (vma->vm_flags & VM_EXEC)) goto out; /* @@ -1653,19 +1729,15 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm, unsigned long address, struct page *page, int node) { - unsigned long haddr = address & HPAGE_PMD_MASK; + spinlock_t *ptl; pg_data_t *pgdat = NODE_DATA(node); int isolated = 0; struct page *new_page = NULL; struct mem_cgroup *memcg = NULL; int page_lru = page_is_file_cache(page); - - /* - * Don't migrate pages that are mapped in multiple processes. - * TODO: Handle false sharing detection instead of this hammer - */ - if (page_mapcount(page) != 1) - goto out_dropref; + unsigned long mmun_start = address & HPAGE_PMD_MASK; + unsigned long mmun_end = mmun_start + HPAGE_PMD_SIZE; + pmd_t orig_entry; /* * Rate-limit the amount of data that is being migrated to a node. @@ -1680,7 +1752,7 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm, if (!new_page) goto out_fail; - page_nid_xchg_last(new_page, page_nid_last(page)); + page_cpupid_xchg_last(new_page, page_cpupid_last(page)); isolated = numamigrate_isolate_page(pgdat, page); if (!isolated) { @@ -1688,6 +1760,9 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm, goto out_fail; } + if (mm_tlb_flush_pending(mm)) + flush_tlb_range(vma, mmun_start, mmun_end); + /* Prepare a page as a migration target */ __set_page_locked(new_page); SetPageSwapBacked(new_page); @@ -1699,9 +1774,12 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm, WARN_ON(PageLRU(new_page)); /* Recheck the target PMD */ - spin_lock(&mm->page_table_lock); - if (unlikely(!pmd_same(*pmd, entry))) { - spin_unlock(&mm->page_table_lock); + mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end); + ptl = pmd_lock(mm, pmd); + if (unlikely(!pmd_same(*pmd, entry) || page_count(page) != 2)) { +fail_putback: + spin_unlock(ptl); + mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); /* Reverse changes made by migrate_page_copy() */ if (TestClearPageActive(new_page)) @@ -1713,12 +1791,13 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm, unlock_page(new_page); put_page(new_page); /* Free it */ - unlock_page(page); + /* Retake the callers reference and putback on LRU */ + get_page(page); putback_lru_page(page); + mod_zone_page_state(page_zone(page), + NR_ISOLATED_ANON + page_lru, -HPAGE_PMD_NR); - count_vm_events(PGMIGRATE_FAIL, HPAGE_PMD_NR); - isolated = 0; - goto out; + goto out_unlock; } /* @@ -1730,23 +1809,43 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm, */ mem_cgroup_prepare_migration(page, new_page, &memcg); + orig_entry = *pmd; entry = mk_pmd(new_page, vma->vm_page_prot); - entry = pmd_mknonnuma(entry); - entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); entry = pmd_mkhuge(entry); + entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); - page_add_new_anon_rmap(new_page, vma, haddr); - - set_pmd_at(mm, haddr, pmd, entry); + /* + * Clear the old entry under pagetable lock and establish the new PTE. + * Any parallel GUP will either observe the old page blocking on the + * page lock, block on the page table lock or observe the new page. + * The SetPageUptodate on the new page and page_add_new_anon_rmap + * guarantee the copy is visible before the pagetable update. + */ + flush_cache_range(vma, mmun_start, mmun_end); + page_add_new_anon_rmap(new_page, vma, mmun_start); + pmdp_clear_flush(vma, mmun_start, pmd); + set_pmd_at(mm, mmun_start, pmd, entry); + flush_tlb_range(vma, mmun_start, mmun_end); update_mmu_cache_pmd(vma, address, &entry); + + if (page_count(page) != 2) { + set_pmd_at(mm, mmun_start, pmd, orig_entry); + flush_tlb_range(vma, mmun_start, mmun_end); + update_mmu_cache_pmd(vma, address, &entry); + page_remove_rmap(new_page); + goto fail_putback; + } + page_remove_rmap(page); + /* * Finish the charge transaction under the page table lock to * prevent split_huge_page() from dividing up the charge * before it's fully transferred to the new page. */ mem_cgroup_end_migration(memcg, page, new_page, true); - spin_unlock(&mm->page_table_lock); + spin_unlock(ptl); + mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); unlock_page(new_page); unlock_page(page); @@ -1756,7 +1855,6 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm, count_vm_events(PGMIGRATE_SUCCESS, HPAGE_PMD_NR); count_vm_numa_events(NUMA_PAGE_MIGRATE, HPAGE_PMD_NR); -out: mod_zone_page_state(page_zone(page), NR_ISOLATED_ANON + page_lru, -HPAGE_PMD_NR); @@ -1765,6 +1863,15 @@ out: out_fail: count_vm_events(PGMIGRATE_FAIL, HPAGE_PMD_NR); out_dropref: + ptl = pmd_lock(mm, pmd); + if (pmd_same(*pmd, entry)) { + entry = pmd_mknonnuma(entry); + set_pmd_at(mm, mmun_start, pmd, entry); + update_mmu_cache_pmd(vma, address, &entry); + } + spin_unlock(ptl); + +out_unlock: unlock_page(page); put_page(page); return 0; |