From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751664AbaJOT1N (ORCPT ); Wed, 15 Oct 2014 15:27:13 -0400 Received: from mail-qc0-f202.google.com ([209.85.216.202]:46718 "EHLO mail-qc0-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750870AbaJOT1M (ORCPT ); Wed, 15 Oct 2014 15:27:12 -0400 From: Yu Zhao To: Andrew Morton , "Kirill A. Shutemov" , Mel Gorman , Rik van Riel , Ingo Molnar , Hugh Dickins , Sasha Levin , Bob Liu , Johannes Weiner , David Rientjes , Vlastimil Babka Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Yu Zhao Subject: [PATCH v2 1/2] mm: free compound page with correct order Date: Wed, 15 Oct 2014 12:20:04 -0700 Message-Id: <1413400805-15547-1-git-send-email-yuzhao@google.com> X-Mailer: git-send-email 2.1.0.rc2.206.gedb03e5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Compound page should be freed by put_page() or free_pages() with correct order. Not doing so will cause tail pages leaked. The compound order can be obtained by compound_order() or use HPAGE_PMD_ORDER in our case. Some people would argue the latter is faster but I prefer the former which is more general. Acked-by: Kirill A. Shutemov Fixes: 97ae17497e99 ("thp: implement refcounting for huge zero page") Cc: stable@vger.kernel.org (v3.8+) Signed-off-by: Yu Zhao --- mm/huge_memory.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 74c78aa..780d12c 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -200,7 +200,7 @@ retry: preempt_disable(); if (cmpxchg(&huge_zero_page, NULL, zero_page)) { preempt_enable(); - __free_page(zero_page); + __free_pages(zero_page, compound_order(zero_page)); goto retry; } @@ -232,7 +232,7 @@ static unsigned long shrink_huge_zero_page_scan(struct shrinker *shrink, if (atomic_cmpxchg(&huge_zero_refcount, 1, 0) == 1) { struct page *zero_page = xchg(&huge_zero_page, NULL); BUG_ON(zero_page == NULL); - __free_page(zero_page); + __free_pages(zero_page, compound_order(zero_page)); return HPAGE_PMD_NR; } -- 2.1.0.rc2.206.gedb03e5