From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753434AbbJFPgk (ORCPT ); Tue, 6 Oct 2015 11:36:40 -0400 Received: from mga11.intel.com ([192.55.52.93]:17391 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753344AbbJFPYV (ORCPT ); Tue, 6 Oct 2015 11:24:21 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.17,644,1437462000"; d="scan'208";a="820576375" 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 , Sasha Levin , linux-kernel@vger.kernel.org, linux-mm@kvack.org, "Kirill A. Shutemov" Subject: [PATCHv12 08/37] khugepaged: ignore pmd tables with THP mapped with ptes Date: Tue, 6 Oct 2015 18:23:35 +0300 Message-Id: <1444145044-72349-9-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.5.3 In-Reply-To: <1444145044-72349-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1444145044-72349-1-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 Tested-by: Sasha Levin Tested-by: Aneesh Kumar K.V Acked-by: Jerome Marchand Acked-by: Vlastimil Babka --- include/trace/events/huge_memory.h | 1 + mm/huge_memory.c | 9 ++++++++- 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/include/trace/events/huge_memory.h b/include/trace/events/huge_memory.h index 1efc7f1dc9bd..11c59ca5e145 100644 --- a/include/trace/events/huge_memory.h +++ b/include/trace/events/huge_memory.h @@ -22,6 +22,7 @@ EM( SCAN_PAGE_LRU, "page_not_in_lru") \ EM( SCAN_PAGE_LOCK, "page_locked") \ EM( SCAN_PAGE_ANON, "page_not_anon") \ + EM( SCAN_PAGE_COMPOUND, "page_compound") \ EM( SCAN_ANY_PROCESS, "no_process_for_page") \ EM( SCAN_VMA_NULL, "vma_null") \ EM( SCAN_VMA_CHECK, "vma_check_failed") \ diff --git a/mm/huge_memory.c b/mm/huge_memory.c index c41e107bddc1..7524618a923c 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -46,6 +46,7 @@ enum scan_result { SCAN_PAGE_LRU, SCAN_PAGE_LOCK, SCAN_PAGE_ANON, + SCAN_PAGE_COMPOUND, SCAN_ANY_PROCESS, SCAN_VMA_NULL, SCAN_VMA_CHECK, @@ -2881,6 +2882,13 @@ static int khugepaged_scan_pmd(struct mm_struct *mm, result = SCAN_PAGE_NULL; goto out_unmap; } + + /* TODO: teach khugepaged to collapse THP mapped with pte */ + if (PageCompound(page)) { + result = SCAN_PAGE_COMPOUND; + goto out_unmap; + } + /* * Record which node the original page is from and save this * information to khugepaged_node_load[]. @@ -2893,7 +2901,6 @@ static int khugepaged_scan_pmd(struct mm_struct *mm, goto out_unmap; } khugepaged_node_load[node]++; - VM_BUG_ON_PAGE(PageCompound(page), page); if (!PageLRU(page)) { result = SCAN_SCAN_ABORT; goto out_unmap; -- 2.5.3