From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752831AbbJSG2o (ORCPT ); Mon, 19 Oct 2015 02:28:44 -0400 Received: from LGEAMRELO11.lge.com ([156.147.23.51]:56315 "EHLO lgeamrelo11.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750924AbbJSG2k (ORCPT ); Mon, 19 Oct 2015 02:28:40 -0400 X-Original-SENDERIP: 156.147.1.125 X-Original-MAILFROM: minchan@kernel.org X-Original-SENDERIP: 10.177.223.161 X-Original-MAILFROM: minchan@kernel.org From: Minchan Kim To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Hugh Dickins , Rik van Riel , Mel Gorman , Michal Hocko , Johannes Weiner , "Kirill A. Shutemov" , Vlastimil Babka , Minchan Kim Subject: [PATCH 2/5] mm: skip huge zero page in MADV_FREE Date: Mon, 19 Oct 2015 15:31:44 +0900 Message-Id: <1445236307-895-3-git-send-email-minchan@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1445236307-895-1-git-send-email-minchan@kernel.org> References: <1445236307-895-1-git-send-email-minchan@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It is pointless to mark huge zero page as freeable. Let's skip it. Signed-off-by: Minchan Kim --- mm/huge_memory.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index f1de4ce583a6..269ed99493f0 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1542,6 +1542,9 @@ int madvise_free_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, struct page *page; pmd_t orig_pmd; + if (is_huge_zero_pmd(*pmd)) + goto out; + orig_pmd = pmdp_huge_get_and_clear(mm, addr, pmd); /* No hugepage in swapcache */ @@ -1553,6 +1556,7 @@ int madvise_free_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, set_pmd_at(mm, addr, pmd, orig_pmd); tlb_remove_pmd_tlb_entry(tlb, pmd, addr); +out: spin_unlock(ptl); ret = 0; } -- 1.9.1