Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933191AbcCKXIE (ORCPT ); Fri, 11 Mar 2016 18:08:04 -0500 Received: from mga11.intel.com ([192.55.52.93]:7597 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753099AbcCKW7d (ORCPT ); Fri, 11 Mar 2016 17:59:33 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,321,1455004800"; d="scan'208";a="922073161" 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, linux-fsdevel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCHv4 08/25] thp: support file pages in zap_huge_pmd() Date: Sat, 12 Mar 2016 01:59:00 +0300 Message-Id: <1457737157-38573-9-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1457737157-38573-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1457737157-38573-1-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: 1402 Lines: 39 split_huge_pmd() for file mappings (and DAX too) is implemented by just clearing pmd entry as we can re-fill this area from page cache on pte level later. This means we don't need deposit page tables when file THP is mapped. Therefore we shouldn't try to withdraw a page table on zap_huge_pmd() file THP PMD. Signed-off-by: Kirill A. Shutemov --- mm/huge_memory.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 44468fb7cdbf..c22144e3fe11 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1684,10 +1684,16 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, struct page *page = pmd_page(orig_pmd); page_remove_rmap(page, true); VM_BUG_ON_PAGE(page_mapcount(page) < 0, page); - add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR); VM_BUG_ON_PAGE(!PageHead(page), page); - pte_free(tlb->mm, pgtable_trans_huge_withdraw(tlb->mm, pmd)); - atomic_long_dec(&tlb->mm->nr_ptes); + if (PageAnon(page)) { + pgtable_t pgtable; + pgtable = pgtable_trans_huge_withdraw(tlb->mm, pmd); + pte_free(tlb->mm, pgtable); + atomic_long_dec(&tlb->mm->nr_ptes); + add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR); + } else { + add_mm_counter(tlb->mm, MM_FILEPAGES, -HPAGE_PMD_NR); + } spin_unlock(ptl); tlb_remove_page(tlb, page); } -- 2.7.0