From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935767AbeBLN64 (ORCPT ); Mon, 12 Feb 2018 08:58:56 -0500 Received: from forwardcorp1g.cmail.yandex.net ([87.250.241.190]:46615 "EHLO forwardcorp1g.cmail.yandex.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934880AbeBLN6y (ORCPT ); Mon, 12 Feb 2018 08:58:54 -0500 Authentication-Results: smtpcorp1p.mail.yandex.net; dkim=pass header.i=@yandex-team.ru Subject: [PATCH v3 1/2] mm/page_ref: use atomic_set_release in page_ref_unfreeze From: Konstantin Khlebnikov To: linux-mm@kvack.org, Andrew Morton , linux-kernel@vger.kernel.org Cc: Michal Hocko , Linus Torvalds , "Kirill A. Shutemov" , Nicholas Piggin Date: Mon, 12 Feb 2018 16:58:50 +0300 Message-ID: <151844393004.210639.4672319312617954272.stgit@buzz> In-Reply-To: <4f64569f-b8ce-54f8-33d9-0e67216bb54c@yandex-team.ru> References: <4f64569f-b8ce-54f8-33d9-0e67216bb54c@yandex-team.ru> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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); }