From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pb0-f44.google.com (mail-pb0-f44.google.com [209.85.160.44]) by kanga.kvack.org (Postfix) with ESMTP id 26528900003 for ; Fri, 27 Sep 2013 09:28:03 -0400 (EDT) Received: by mail-pb0-f44.google.com with SMTP id xa7so2565144pbc.31 for ; Fri, 27 Sep 2013 06:28:02 -0700 (PDT) From: 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> In-Reply-To: <1380288468-5551-1-git-send-email-mgorman@suse.de> References: <1380288468-5551-1-git-send-email-mgorman@suse.de> Sender: owner-linux-mm@kvack.org List-ID: To: Peter Zijlstra , Rik van Riel Cc: Srikar Dronamraju , Ingo Molnar , Andrea Arcangeli , Johannes Weiner , Linux-MM , LKML , Mel Gorman 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 -- 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