From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754121Ab3LRTTf (ORCPT ); Wed, 18 Dec 2013 14:19:35 -0500 Received: from mx1.redhat.com ([209.132.183.28]:3602 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752452Ab3LRTTb (ORCPT ); Wed, 18 Dec 2013 14:19:31 -0500 Date: Wed, 18 Dec 2013 20:19:58 +0100 From: Oleg Nesterov To: Andrea Arcangeli , Andrew Morton Cc: Thomas Gleixner , Linus Torvalds , Dave Jones , Darren Hart , Peter Zijlstra , Mel Gorman , linux-kernel@vger.kernel.org Subject: [PATCH -mm 4/7] mm: thp: turn put_compound_page() into __put_page_tail() Message-ID: <20131218191958.GA8330@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131218191913.GA6464@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org put_page(page) calls put_compound_page() if PageCompound(), but put_compound_page() falls back to __put_nontail_page() if the page is non-tail. So we can simply shift the PageTail() logic from put_compound_page() to put_page(), and put_page() can use __put_nontail_page() otherwise. The patch also renames put_compound_page() to __put_page_tail() to reflect the semantics change. And this way put_page() looks more symmetrical with get_page(). Signed-off-by: Oleg Nesterov --- mm/swap.c | 17 ++++++----------- 1 files changed, 6 insertions(+), 11 deletions(-) diff --git a/mm/swap.c b/mm/swap.c index b0e65b6..0400f3b 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -93,15 +93,10 @@ static void __put_nontail_page(struct page *page) } } -static void put_compound_page(struct page *page) +static void __put_page_tail(struct page *page) { struct page *page_head; - if (likely(!PageTail(page))) { - __put_nontail_page(page); - return; - } - /* __split_huge_page_refcount can run under us */ page_head = compound_trans_head(page); @@ -222,10 +217,10 @@ out_put_single: void put_page(struct page *page) { - if (unlikely(PageCompound(page))) - put_compound_page(page); - else if (put_page_testzero(page)) - __put_single_page(page); + if (unlikely(PageTail(page))) + __put_page_tail(page); + else + __put_nontail_page(page); } EXPORT_SYMBOL(put_page); @@ -247,7 +242,7 @@ bool __get_page_tail(struct page *page) bool got; struct page *page_head = compound_trans_head(page); - /* Ref to put_compound_page() comment. */ + /* Ref to __put_page_tail() comment. */ if (!__compound_tail_refcounted(page_head)) { smp_rmb(); if (likely(PageTail(page))) { -- 1.5.5.1