From b0943d61b8fa420180f92f64ef67662b4f6cc493 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Wed, 18 Dec 2013 17:08:46 -0800 Subject: [PATCH] mm: numa: defer TLB flush for THP migration as long as possible THP migration can fail for a variety of reasons. Avoid flushing the TLB to deal with THP migration races until the copy is ready to start. Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel Cc: Alex Thorlton Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/huge_memory.c | 7 ------- mm/migrate.c | 3 +++ 2 files changed, 3 insertions(+), 7 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 3d2783e..7de1bf8 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1377,13 +1377,6 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, } /* - * The page_table_lock above provides a memory barrier - * with change_protection_range. - */ - if (mm_tlb_flush_pending(mm)) - flush_tlb_range(vma, haddr, haddr + HPAGE_PMD_SIZE); - - /* * Migrate the THP to the requested node, returns with page unlocked * and pmd_numa cleared. */ diff --git a/mm/migrate.c b/mm/migrate.c index cfb4190..e9b7102 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1759,6 +1759,9 @@ 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); -- 2.7.4