From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f175.google.com (mail-io0-f175.google.com [209.85.223.175]) by kanga.kvack.org (Postfix) with ESMTP id CD9C56B0254 for ; Fri, 18 Sep 2015 11:02:02 -0400 (EDT) Received: by iofh134 with SMTP id h134so59216824iof.0 for ; Fri, 18 Sep 2015 08:02:02 -0700 (PDT) Received: from mga14.intel.com (mga14.intel.com. [192.55.52.115]) by mx.google.com with ESMTP id 75si7135471ioq.70.2015.09.18.08.01.54 for ; Fri, 18 Sep 2015 08:01:55 -0700 (PDT) From: "Kirill A. Shutemov" Subject: [PATCHv11 08/37] khugepaged: ignore pmd tables with THP mapped with ptes Date: Fri, 18 Sep 2015 18:01:11 +0300 Message-Id: <1442588500-77331-9-git-send-email-kirill.shutemov@linux.intel.com> In-Reply-To: <1442588500-77331-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1442588500-77331-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: 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" 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 | 11 +++++++++-- 2 files changed, 10 insertions(+), 2 deletions(-) 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 1e87739ceefc..44472136a67f 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, @@ -2887,6 +2888,13 @@ 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[]. @@ -2899,9 +2907,8 @@ 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; + result = SCAN_SCAN_ABORT; goto out_unmap; } if (PageLocked(page)) { -- 2.5.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org