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 <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Alex Thorlton <athorlton@sgi.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 @@
}
/*
- * 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 @@
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);