From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753711Ab3I0N2R (ORCPT ); Fri, 27 Sep 2013 09:28:17 -0400 Received: from cantor2.suse.de ([195.135.220.15]:55557 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753532Ab3I0N2A (ORCPT ); Fri, 27 Sep 2013 09:28:00 -0400 From: Mel Gorman To: Peter Zijlstra , Rik van Riel Cc: Srikar Dronamraju , Ingo Molnar , Andrea Arcangeli , Johannes Weiner , Linux-MM , LKML , Mel Gorman Subject: [PATCH 08/63] mm: Do not flush TLB during protection change if !pte_present && !migration_entry Date: Fri, 27 Sep 2013 14:26:53 +0100 Message-Id: <1380288468-5551-9-git-send-email-mgorman@suse.de> X-Mailer: git-send-email 1.8.1.4 In-Reply-To: <1380288468-5551-1-git-send-email-mgorman@suse.de> References: <1380288468-5551-1-git-send-email-mgorman@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org NUMA PTE scanning is expensive both in terms of the scanning itself and the TLB flush if there are any updates. Currently non-present PTEs are accounted for as an update and incurring a TLB flush where it is only necessary for anonymous migration entries. This patch addresses the problem and should reduce TLB flushes. Signed-off-by: Mel Gorman --- mm/mprotect.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/mprotect.c b/mm/mprotect.c index 2bbb648..7bdbd4b 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -101,8 +101,9 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, make_migration_entry_read(&entry); set_pte_at(mm, addr, pte, swp_entry_to_pte(entry)); + + pages++; } - pages++; } } while (pte++, addr += PAGE_SIZE, addr != end); arch_leave_lazy_mmu_mode(); -- 1.8.1.4