diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/huge_memory.c | 145 | ||||
| -rw-r--r-- | mm/internal.h | 18 | ||||
| -rw-r--r-- | mm/migrate.c | 177 |
3 files changed, 77 insertions, 263 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index f3a3138d33e9..de7a8c2a0c80 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1423,92 +1423,20 @@ out: vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; - pmd_t pmd = vmf->orig_pmd; - struct anon_vma *anon_vma = NULL; + pmd_t oldpmd = vmf->orig_pmd; + pmd_t pmd; struct page *page; unsigned long haddr = vmf->address & HPAGE_PMD_MASK; - int page_nid = NUMA_NO_NODE, this_nid = numa_node_id(); + int page_nid = NUMA_NO_NODE; int target_nid, last_cpupid = -1; - bool page_locked; bool migrated = false; - bool was_writable; + bool was_writable = pmd_savedwrite(oldpmd); int flags = 0; vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd); - if (unlikely(!pmd_same(pmd, *vmf->pmd))) - goto out_unlock; - - /* - * If there are potential migrations, wait for completion and retry - * without disrupting NUMA hinting information. Do not relock and - * check_same as the page may no longer be mapped. - */ - if (unlikely(pmd_trans_migrating(*vmf->pmd))) { - page = pmd_page(*vmf->pmd); - if (!get_page_unless_zero(page)) - goto out_unlock; - spin_unlock(vmf->ptl); - put_and_wait_on_page_locked(page, TASK_UNINTERRUPTIBLE); - goto out; - } - - page = pmd_page(pmd); - BUG_ON(is_huge_zero_page(page)); - page_nid = page_to_nid(page); - last_cpupid = page_cpupid_last(page); - count_vm_numa_event(NUMA_HINT_FAULTS); - if (page_nid == this_nid) { - count_vm_numa_event(NUMA_HINT_FAULTS_LOCAL); - flags |= TNF_FAULT_LOCAL; - } - - /* See similar comment in do_numa_page for explanation */ - if (!pmd_savedwrite(pmd)) - flags |= TNF_NO_GROUP; - - /* - * Acquire the page lock to serialise THP migrations but avoid dropping - * page_table_lock if at all possible - */ - page_locked = trylock_page(page); - target_nid = mpol_misplaced(page, vma, haddr); - /* Migration could have started since the pmd_trans_migrating check */ - if (!page_locked) { - page_nid = NUMA_NO_NODE; - if (!get_page_unless_zero(page)) - goto out_unlock; + if (unlikely(!pmd_same(oldpmd, *vmf->pmd))) { spin_unlock(vmf->ptl); - put_and_wait_on_page_locked(page, TASK_UNINTERRUPTIBLE); goto out; - } else if (target_nid == NUMA_NO_NODE) { - /* There are no parallel migrations and page is in the right - * node. Clear the numa hinting info in this pmd. - */ - goto clear_pmdnuma; - } - - /* - * Page is misplaced. Page lock serialises migrations. Acquire anon_vma - * to serialises splits - */ - get_page(page); - spin_unlock(vmf->ptl); - anon_vma = page_lock_anon_vma_read(page); - - /* Confirm the PMD did not change while page_table_lock was released */ - spin_lock(vmf->ptl); - if (unlikely(!pmd_same(pmd, *vmf->pmd))) { - unlock_page(page); - put_page(page); - page_nid = NUMA_NO_NODE; - goto out_unlock; - } - - /* Bail if we fail to protect against THP splits for any reason */ - if (unlikely(!anon_vma)) { - put_page(page); - page_nid = NUMA_NO_NODE; - goto clear_pmdnuma; } /* @@ -1537,43 +1465,58 @@ vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf) haddr + HPAGE_PMD_SIZE); } - /* - * Migrate the THP to the requested node, returns with page unlocked - * and access rights restored. - */ + pmd = pmd_modify(oldpmd, vma->vm_page_prot); + page = vm_normal_page_pmd(vma, haddr, pmd); + if (!page) + goto out_map; + + /* See similar comment in do_numa_page for explanation */ + if (!was_writable) + flags |= TNF_NO_GROUP; + + page_nid = page_to_nid(page); + last_cpupid = page_cpupid_last(page); + target_nid = numa_migrate_prep(page, vma, haddr, page_nid, + &flags); + + if (target_nid == NUMA_NO_NODE) { + put_page(page); + goto out_map; + } + spin_unlock(vmf->ptl); - migrated = migrate_misplaced_transhuge_page(vma->vm_mm, vma, - vmf->pmd, pmd, vmf->address, page, target_nid); + migrated = migrate_misplaced_page(page, vma, target_nid); if (migrated) { flags |= TNF_MIGRATED; page_nid = target_nid; - } else + } else { flags |= TNF_MIGRATE_FAIL; - - goto out; -clear_pmdnuma: - BUG_ON(!PageLocked(page)); - was_writable = pmd_savedwrite(pmd); - pmd = pmd_modify(pmd, vma->vm_page_prot); - pmd = pmd_mkyoung(pmd); - if (was_writable) - pmd = pmd_mkwrite(pmd); - set_pmd_at(vma->vm_mm, haddr, vmf->pmd, pmd); - update_mmu_cache_pmd(vma, vmf->address, vmf->pmd); - unlock_page(page); -out_unlock: - spin_unlock(vmf->ptl); + vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd); + if (unlikely(!pmd_same(oldpmd, *vmf->pmd))) { + spin_unlock(vmf->ptl); + goto out; + } + goto out_map; + } out: - if (anon_vma) - page_unlock_anon_vma_read(anon_vma); - if (page_nid != NUMA_NO_NODE) task_numa_fault(last_cpupid, page_nid, HPAGE_PMD_NR, flags); return 0; + +out_map: + /* Restore the PMD */ + pmd = pmd_modify(oldpmd, vma->vm_page_prot); + pmd = pmd_mkyoung(pmd); + if (was_writable) + pmd = pmd_mkwrite(pmd); + set_pmd_at(vma->vm_mm, haddr, vmf->pmd, pmd); + update_mmu_cache_pmd(vma, vmf->address, vmf->pmd); + spin_unlock(vmf->ptl); + goto out; } /* diff --git a/mm/internal.h b/mm/internal.h index a4942f9867a3..d565eb94d6ec 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -369,23 +369,6 @@ extern unsigned int munlock_vma_page(struct page *page); */ extern void clear_page_mlock(struct page *page); -/* - * mlock_migrate_page - called only from migrate_misplaced_transhuge_page() - * (because that does not go through the full procedure of migration ptes): - * to migrate the Mlocked page flag; update statistics. - */ -static inline void mlock_migrate_page(struct page *newpage, struct page *page) -{ - if (TestClearPageMlocked(page)) { - int nr_pages = thp_nr_pages(page); - - /* Holding pmd lock, no change in irq context: __mod is safe */ - __mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages); - SetPageMlocked(newpage); - __mod_zone_page_state(page_zone(newpage), NR_MLOCK, nr_pages); - } -} - extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma); /* @@ -461,7 +444,6 @@ static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf, #else /* !CONFIG_MMU */ static inline void clear_page_mlock(struct page *page) { } static inline void mlock_vma_page(struct page *page) { } -static inline void mlock_migrate_page(struct page *new, struct page *old) { } static inline void vunmap_range_noflush(unsigned long start, unsigned long end) { } diff --git a/mm/migrate.c b/mm/migrate.c index 9bd6bc12aa72..b7e330900b86 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -2048,6 +2048,23 @@ static struct page *alloc_misplaced_dst_page(struct page *page, return newpage; } +static struct page *alloc_misplaced_dst_page_thp(struct page *page, + unsigned long data) +{ + int nid = (int) data; + struct page *newpage; + + newpage = alloc_pages_node(nid, (GFP_TRANSHUGE_LIGHT | __GFP_THISNODE), + HPAGE_PMD_ORDER); + if (!newpage) + goto out; + + prep_transhuge_page(newpage); + +out: + return newpage; +} + static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page) { int page_lru; @@ -2086,12 +2103,6 @@ static 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); -} - /* * Attempt to migrate a misplaced page to the specified destination * node. Caller is expected to have an elevated reference count on @@ -2104,6 +2115,20 @@ int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma, int isolated; int nr_remaining; LIST_HEAD(migratepages); + new_page_t *new; + bool compound; + + /* + * PTE mapped THP or HugeTLB page can't reach here so the page could + * be either base page or THP. And it must be head page if it is + * THP. + */ + compound = PageTransHuge(page); + + if (compound) + new = alloc_misplaced_dst_page_thp; + else + new = alloc_misplaced_dst_page; /* * Don't migrate file pages that are mapped in multiple processes @@ -2125,9 +2150,8 @@ int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma, goto out; list_add(&page->lru, &migratepages); - nr_remaining = migrate_pages(&migratepages, alloc_misplaced_dst_page, - NULL, node, MIGRATE_ASYNC, - MR_NUMA_MISPLACED); + nr_remaining = migrate_pages(&migratepages, *new, NULL, node, + MIGRATE_ASYNC, MR_NUMA_MISPLACED); if (nr_remaining) { if (!list_empty(&migratepages)) { list_del(&page->lru); @@ -2146,141 +2170,6 @@ out: return 0; } #endif /* CONFIG_NUMA_BALANCING */ - -#if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE) -/* - * Migrates a THP to a given target node. page must be locked and is unlocked - * before returning. - */ -int migrate_misplaced_transhuge_page(struct mm_struct *mm, - struct vm_area_struct *vma, - pmd_t *pmd, pmd_t entry, - unsigned long address, - struct page *page, int node) -{ - spinlock_t *ptl; - pg_data_t *pgdat = NODE_DATA(node); - int isolated = 0; - struct page *new_page = NULL; - int page_lru = page_is_file_lru(page); - unsigned long start = address & HPAGE_PMD_MASK; - - new_page = alloc_pages_node(node, - (GFP_TRANSHUGE_LIGHT | __GFP_THISNODE), - HPAGE_PMD_ORDER); - if (!new_page) - goto out_fail; - prep_transhuge_page(new_page); - - isolated = numamigrate_isolate_page(pgdat, page); - if (!isolated) { - put_page(new_page); - goto out_fail; - } - - /* Prepare a page as a migration target */ - __SetPageLocked(new_page); - if (PageSwapBacked(page)) - __SetPageSwapBacked(new_page); - - /* anon mapping, we can simply copy page->mapping to the new page: */ - new_page->mapping = page->mapping; - new_page->index = page->index; - /* flush the cache before copying using the kernel virtual address */ - flush_cache_range(vma, start, start + HPAGE_PMD_SIZE); - migrate_page_copy(new_page, page); - WARN_ON(PageLRU(new_page)); - - /* Recheck the target PMD */ - ptl = pmd_lock(mm, pmd); - if (unlikely(!pmd_same(*pmd, entry) || !page_ref_freeze(page, 2))) { - spin_unlock(ptl); - - /* Reverse changes made by migrate_page_copy() */ - if (TestClearPageActive(new_page)) - SetPageActive(page); - if (TestClearPageUnevictable(new_page)) - SetPageUnevictable(page); - - unlock_page(new_page); - put_page(new_page); /* Free it */ - - /* Retake the callers reference and putback on LRU */ - get_page(page); - putback_lru_page(page); - mod_node_page_state(page_pgdat(page), - NR_ISOLATED_ANON + page_lru, -HPAGE_PMD_NR); - - goto out_unlock; - } - - entry = mk_huge_pmd(new_page, vma->vm_page_prot); - entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); - - /* - * Overwrite 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. - */ - page_add_anon_rmap(new_page, vma, start, true); - /* - * At this point the pmd is numa/protnone (i.e. non present) and the TLB - * has already been flushed globally. So no TLB can be currently - * caching this non present pmd mapping. There's no need to clear the - * pmd before doing set_pmd_at(), nor to flush the TLB after - * set_pmd_at(). Clearing the pmd here would introduce a race - * condition against MADV_DONTNEED, because MADV_DONTNEED only holds the - * mmap_lock for reading. If the pmd is set to NULL at any given time, - * MADV_DONTNEED won't wait on the pmd lock and it'll skip clearing this - * pmd. - */ - set_pmd_at(mm, start, pmd, entry); - update_mmu_cache_pmd(vma, address, &entry); - - page_ref_unfreeze(page, 2); - mlock_migrate_page(new_page, page); - page_remove_rmap(page, true); - set_page_owner_migrate_reason(new_page, MR_NUMA_MISPLACED); - - spin_unlock(ptl); - - /* Take an "isolate" reference and put new page on the LRU. */ - get_page(new_page); - putback_lru_page(new_page); - - unlock_page(new_page); - unlock_page(page); - put_page(page); /* Drop the rmap reference */ - put_page(page); /* Drop the LRU isolation reference */ - - count_vm_events(PGMIGRATE_SUCCESS, HPAGE_PMD_NR); - count_vm_numa_events(NUMA_PAGE_MIGRATE, HPAGE_PMD_NR); - - mod_node_page_state(page_pgdat(page), - NR_ISOLATED_ANON + page_lru, - -HPAGE_PMD_NR); - return isolated; - -out_fail: - count_vm_events(PGMIGRATE_FAIL, HPAGE_PMD_NR); - ptl = pmd_lock(mm, pmd); - if (pmd_same(*pmd, entry)) { - entry = pmd_modify(entry, vma->vm_page_prot); - set_pmd_at(mm, start, pmd, entry); - update_mmu_cache_pmd(vma, address, &entry); - } - spin_unlock(ptl); - -out_unlock: - unlock_page(page); - put_page(page); - return 0; -} -#endif /* CONFIG_NUMA_BALANCING */ - #endif /* CONFIG_NUMA */ #ifdef CONFIG_DEVICE_PRIVATE |