Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932882AbcCCRCS (ORCPT ); Thu, 3 Mar 2016 12:02:18 -0500 Received: from mga04.intel.com ([192.55.52.120]:15178 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758244AbcCCQwz (ORCPT ); Thu, 3 Mar 2016 11:52:55 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.22,532,1449561600"; d="scan'208";a="900497665" From: "Kirill A. Shutemov" To: Hugh Dickins , Andrea Arcangeli , Andrew Morton Cc: Dave Hansen , Vlastimil Babka , Christoph Lameter , Naoya Horiguchi , Jerome Marchand , Yang Shi , Sasha Levin , linux-kernel@vger.kernel.org, linux-mm@kvack.org, "Kirill A. Shutemov" Subject: [PATCHv3 13/29] thp: handle file pages in split_huge_pmd() Date: Thu, 3 Mar 2016 19:52:03 +0300 Message-Id: <1457023939-98083-14-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1457023939-98083-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1457023939-98083-1-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 Content-Length: 1069 Lines: 33 Splitting THP PMD is simple: just unmap it as in DAX case. Unlike DAX, we also remove the page from rmap and drop reference. Signed-off-by: Kirill A. Shutemov --- mm/huge_memory.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 15704484abf4..985041c453bf 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2900,10 +2900,16 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd, count_vm_event(THP_SPLIT_PMD); - if (vma_is_dax(vma)) { - pmd_t _pmd = pmdp_huge_clear_flush_notify(vma, haddr, pmd); + if (!vma_is_anonymous(vma)) { + _pmd = pmdp_huge_clear_flush_notify(vma, haddr, pmd); if (is_huge_zero_pmd(_pmd)) put_huge_zero_page(); + if (vma_is_dax(vma)) + return; + page = pmd_page(_pmd); + page_remove_rmap(page, true); + put_page(page); + add_mm_counter(mm, MM_FILEPAGES, -HPAGE_PMD_NR); return; } else if (is_huge_zero_pmd(*pmd)) { return __split_huge_zero_page_pmd(vma, haddr, pmd); -- 2.7.0