On Thu, Jun 08, 2017 at 12:24:33PM +0100, Will Deacon wrote: > [+ PeterZ] > > On Thu, Jun 08, 2017 at 01:07:02PM +0200, Vlastimil Babka wrote: > > On 06/08/2017 12:40 PM, Kirill A. Shutemov wrote: > > > On Thu, Jun 08, 2017 at 11:38:21AM +0200, Vlastimil Babka wrote: > > >> On 06/06/2017 07:58 PM, Will Deacon wrote: > > >>> include/linux/page_ref.h | 1 + > > >>> 1 file changed, 1 insertion(+) > > >>> > > >>> diff --git a/include/linux/page_ref.h b/include/linux/page_ref.h > > >>> index 610e13271918..74d32d7905cb 100644 > > >>> --- a/include/linux/page_ref.h > > >>> +++ b/include/linux/page_ref.h > > >>> @@ -174,6 +174,7 @@ 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__before_atomic(); > > >>> atomic_set(&page->_refcount, count);
So depending on what it actually required, we do have atomic_set_release() (atomic_t equivalent to smp_store_release()).
