thp: compound_lock
Add a new compound_lock() needed to serialize put_page against
__split_huge_page_refcount().
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 4805fde..5a743cc 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -108,6 +108,9 @@
#ifdef CONFIG_MEMORY_FAILURE
PG_hwpoison, /* hardware poisoned page. Don't touch */
#endif
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ PG_compound_lock,
+#endif
__NR_PAGEFLAGS,
/* Filesystems */
@@ -397,6 +400,12 @@
#define __PG_MLOCKED 0
#endif
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+#define __PG_COMPOUND_LOCK (1 << PG_compound_lock)
+#else
+#define __PG_COMPOUND_LOCK 0
+#endif
+
/*
* Flags checked when a page is freed. Pages being freed should not have
* these flags set. It they are, there is a problem.
@@ -406,7 +415,8 @@
1 << PG_private | 1 << PG_private_2 | \
1 << PG_buddy | 1 << PG_writeback | 1 << PG_reserved | \
1 << PG_slab | 1 << PG_swapcache | 1 << PG_active | \
- 1 << PG_unevictable | __PG_MLOCKED | __PG_HWPOISON)
+ 1 << PG_unevictable | __PG_MLOCKED | __PG_HWPOISON | \
+ __PG_COMPOUND_LOCK)
/*
* Flags checked when a page is prepped for return by the page allocator.