From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760846Ab3LIHKT (ORCPT ); Mon, 9 Dec 2013 02:10:19 -0500 Received: from cantor2.suse.de ([195.135.220.15]:40176 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760624Ab3LIHJZ (ORCPT ); Mon, 9 Dec 2013 02:09:25 -0500 From: Mel Gorman To: Andrew Morton Cc: Alex Thorlton , Rik van Riel , Linux-MM , LKML , Mel Gorman Subject: [PATCH 12/18] mm: numa: Defer TLB flush for THP migration as long as possible Date: Mon, 9 Dec 2013 07:09:06 +0000 Message-Id: <1386572952-1191-13-git-send-email-mgorman@suse.de> X-Mailer: git-send-email 1.8.4 In-Reply-To: <1386572952-1191-1-git-send-email-mgorman@suse.de> References: <1386572952-1191-1-git-send-email-mgorman@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org THP migration can fail for a variety of reasons. Avoid flushing the TLB to deal with THP migration races until the copy is ready to start. Cc: stable@vger.kernel.org Signed-off-by: Mel Gorman --- mm/huge_memory.c | 7 ------- mm/migrate.c | 6 ++++++ 2 files changed, 6 insertions(+), 7 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index e3a5ee2..e3b6a75 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1377,13 +1377,6 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, } /* - * The page_table_lock above provides a memory barrier - * with change_protection_range. - */ - if (tlb_flush_pending(mm)) - flush_tlb_range(vma, haddr, haddr + HPAGE_PMD_SIZE); - - /* * Migrate the THP to the requested node, returns with page unlocked * and pmd_numa cleared. */ diff --git a/mm/migrate.c b/mm/migrate.c index cfb4190..5372521 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1759,6 +1759,12 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm, goto out_fail; } + /* PTL provides a memory barrier with change_protection_range */ + ptl = pmd_lock(mm, pmd); + if (tlb_flush_pending(mm)) + flush_tlb_range(vma, mmun_start, mmun_end); + spin_unlock(ptl); + /* Prepare a page as a migration target */ __set_page_locked(new_page); SetPageSwapBacked(new_page); -- 1.8.4