From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754371Ab2HIJIq (ORCPT ); Thu, 9 Aug 2012 05:08:46 -0400 Received: from mga01.intel.com ([192.55.52.88]:55175 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750996Ab2HIJIk (ORCPT ); Thu, 9 Aug 2012 05:08:40 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.77,739,1336374000"; d="scan'208";a="205376419" From: "Kirill A. Shutemov" To: Andrew Morton , Andrea Arcangeli , linux-mm@kvack.org Cc: Andi Kleen , "H. Peter Anvin" , linux-kernel@vger.kernel.org, "Kirill A. Shutemov" , "Kirill A. Shutemov" Subject: [PATCH, RFC 2/9] thp: zap_huge_pmd(): zap huge zero pmd Date: Thu, 9 Aug 2012 12:08:13 +0300 Message-Id: <1344503300-9507-3-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1344503300-9507-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1344503300-9507-1-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 From: "Kirill A. Shutemov" We don't have a real page to zap in huge zero page case. Let's just clear pmd and remove it from tlb. Signed-off-by: Kirill A. Shutemov --- mm/huge_memory.c | 27 +++++++++++++++++---------- 1 files changed, 17 insertions(+), 10 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 88e0a7a..9dcb9e6 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1071,16 +1071,23 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, struct page *page; pgtable_t pgtable; pgtable = get_pmd_huge_pte(tlb->mm); - page = pmd_page(*pmd); - pmd_clear(pmd); - tlb_remove_pmd_tlb_entry(tlb, pmd, addr); - page_remove_rmap(page); - VM_BUG_ON(page_mapcount(page) < 0); - add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR); - VM_BUG_ON(!PageHead(page)); - tlb->mm->nr_ptes--; - spin_unlock(&tlb->mm->page_table_lock); - tlb_remove_page(tlb, page); + if (is_huge_zero_pmd(*pmd)) { + pmd_clear(pmd); + tlb_remove_pmd_tlb_entry(tlb, pmd, addr); + tlb->mm->nr_ptes--; + spin_unlock(&tlb->mm->page_table_lock); + } else { + page = pmd_page(*pmd); + pmd_clear(pmd); + tlb_remove_pmd_tlb_entry(tlb, pmd, addr); + page_remove_rmap(page); + VM_BUG_ON(page_mapcount(page) < 0); + add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR); + VM_BUG_ON(!PageHead(page)); + tlb->mm->nr_ptes--; + spin_unlock(&tlb->mm->page_table_lock); + tlb_remove_page(tlb, page); + } pte_free(tlb->mm, pgtable); ret = 1; } -- 1.7.7.6