From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f176.google.com (mail-pf0-f176.google.com [209.85.192.176]) by kanga.kvack.org (Postfix) with ESMTP id 435716B0270 for ; Wed, 6 Apr 2016 18:51:45 -0400 (EDT) Received: by mail-pf0-f176.google.com with SMTP id 184so42460496pff.0 for ; Wed, 06 Apr 2016 15:51:45 -0700 (PDT) Received: from mga14.intel.com (mga14.intel.com. [192.55.52.115]) by mx.google.com with ESMTP id qn9si7245269pab.159.2016.04.06.15.51.31 for ; Wed, 06 Apr 2016 15:51:31 -0700 (PDT) From: "Kirill A. Shutemov" Subject: [PATCHv6 08/30] thp: support file pages in zap_huge_pmd() Date: Thu, 7 Apr 2016 01:50:58 +0300 Message-Id: <1459983080-106718-9-git-send-email-kirill.shutemov@linux.intel.com> In-Reply-To: <1459983080-106718-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1459983080-106718-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Hugh Dickins , Andrea Arcangeli , Andrew Morton Cc: Dave Hansen , Vlastimil Babka , Christoph Lameter , Naoya Horiguchi , Jerome Marchand , Yang Shi , Sasha Levin , Andres Lagar-Cavilla , Ning Qu , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, "Kirill A. Shutemov" 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 8c76f12ea097..5975c14d66ab 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1696,10 +1696,16 @@ 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); } -- 2.8.0.rc3 -- 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