diff options
Diffstat (limited to 'mm/migrate.c')
| -rw-r--r-- | mm/migrate.c | 92 |
1 files changed, 73 insertions, 19 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index c04692774e8..bb940045fe8 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -130,7 +130,7 @@ 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) @@ -249,9 +249,10 @@ 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); } @@ -441,10 +442,60 @@ 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 @@ -481,6 +532,13 @@ 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); /* @@ -1500,7 +1558,7 @@ 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; } @@ -1601,7 +1659,8 @@ int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page) * 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; @@ -1609,10 +1668,11 @@ 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; /* @@ -1655,6 +1715,7 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm, unsigned long address, struct page *page, int node) { + spinlock_t *ptl; unsigned long haddr = address & HPAGE_PMD_MASK; pg_data_t *pgdat = NODE_DATA(node); int isolated = 0; @@ -1663,13 +1724,6 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm, 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; - - /* * Rate-limit the amount of data that is being migrated to a node. * Optimal placement is no good if the memory bus is saturated and * all the time is being spent migrating! @@ -1682,7 +1736,7 @@ 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) { @@ -1701,9 +1755,9 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm, WARN_ON(PageLRU(new_page)); /* Recheck the target PMD */ - spin_lock(&mm->page_table_lock); + ptl = pmd_lock(mm, pmd); if (unlikely(!pmd_same(*pmd, entry))) { - spin_unlock(&mm->page_table_lock); + spin_unlock(ptl); /* Reverse changes made by migrate_page_copy() */ if (TestClearPageActive(new_page)) @@ -1748,7 +1802,7 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm, * 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); unlock_page(new_page); unlock_page(page); |