Commit 03f5d58f authored Apr 05, 2018 by Konstantin Khlebnikov Committed by Linus Torvalds Apr 05, 2018

mm/page_ref: use atomic_set_release in page_ref_unfreeze

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

Link: http://lkml.kernel.org/r/151844393004.210639.4672319312617954272.stgit@buzz

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent e92bb4dd

include/linux/page_ref.h

+1 −2

Original line number	Original line	Diff line number	Diff line
	@@ -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_PAGE(page_count(page) != 0, page);
	VM_BUG_ON(count == 0);		VM_BUG_ON(count == 0);

	smp_mb();		atomic_set_release(&page->_refcount, count);
	atomic_set(&page->_refcount, count);
	if (page_ref_tracepoint_active(__tracepoint_page_ref_unfreeze))		if (page_ref_tracepoint_active(__tracepoint_page_ref_unfreeze))
	__page_ref_unfreeze(page, count);		__page_ref_unfreeze(page, count);
	}		}