From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756509AbbBLQVl (ORCPT ); Thu, 12 Feb 2015 11:21:41 -0500 Received: from mga02.intel.com ([134.134.136.20]:24714 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756436AbbBLQT3 (ORCPT ); Thu, 12 Feb 2015 11:19:29 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.09,565,1418112000"; d="scan'208";a="651295754" From: "Kirill A. Shutemov" To: Andrew Morton , Andrea Arcangeli , Hugh Dickins Cc: Dave Hansen , Mel Gorman , Rik van Riel , Vlastimil Babka , Christoph Lameter , Naoya Horiguchi , Steve Capper , "Aneesh Kumar K.V" , Johannes Weiner , Michal Hocko , Jerome Marchand , linux-kernel@vger.kernel.org, linux-mm@kvack.org, "Kirill A. Shutemov" Subject: [PATCHv3 10/24] khugepaged: ignore pmd tables with THP mapped with ptes Date: Thu, 12 Feb 2015 18:18:24 +0200 Message-Id: <1423757918-197669-11-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1423757918-197669-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1423757918-197669-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Prepare khugepaged to see compound pages mapped with pte. For now we won't collapse the pmd table with such pte. khugepaged is subject for future rework wrt new refcounting. Signed-off-by: Kirill A. Shutemov --- mm/huge_memory.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 284d1f13247a..9d18e9bafb26 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2735,6 +2735,11 @@ static int khugepaged_scan_pmd(struct mm_struct *mm, page = vm_normal_page(vma, _address, pteval); if (unlikely(!page)) goto out_unmap; + + /* TODO: teach khugepaged to collapse THP mapped with pte */ + if (PageCompound(page)) + goto out_unmap; + /* * Record which node the original page is from and save this * information to khugepaged_node_load[]. @@ -2745,7 +2750,6 @@ static int khugepaged_scan_pmd(struct mm_struct *mm, if (khugepaged_scan_abort(node)) goto out_unmap; khugepaged_node_load[node]++; - VM_BUG_ON_PAGE(PageCompound(page), page); if (!PageLRU(page) || PageLocked(page) || !PageAnon(page)) goto out_unmap; /* -- 2.1.4