[PATCH v3 1/2] mm/page_ref: use atomic_set_release in page_ref_unfreeze

[Konstantin Khlebnikov]

page_ref_unfreeze() has exactly that semantic. No functional
changes: just minus one barrier and proper handling of PPro errata.

Signed-off-by: Konstantin Khlebnikov <khlebni...@yandex-team.ru>
---
 include/linux/page_ref.h |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/include/linux/page_ref.h b/include/linux/page_ref.h
index 760d74a0e9a9..14d14beb1f7f 100644
--- a/include/linux/page_ref.h
+++ b/include/linux/page_ref.h
@@ -175,8 +175,7 @@ static inline void page_ref_unfreeze(struct page *page, int 
count)
        VM_BUG_ON_PAGE(page_count(page) != 0, page);
        VM_BUG_ON(count == 0);
 
-       smp_mb();
-       atomic_set(&page->_refcount, count);
+       atomic_set_release(&page->_refcount, count);
        if (page_ref_tracepoint_active(__tracepoint_page_ref_unfreeze))
                __page_ref_unfreeze(page, count);
 }