Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755824AbaGHArV (ORCPT ); Mon, 7 Jul 2014 20:47:21 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:55567 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753658AbaGGXyZ (ORCPT ); Mon, 7 Jul 2014 19:54:25 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Rik van Riel , Naoya Horiguchi , Sunil Pandey , Peter Zijlstra , Andrew Morton , Johannes Weiner , "Kirill A. Shutemov" , Linus Torvalds , Mel Gorman , linux-mm@kvack.org, lwoodman@redhat.com, dave.hansen@intel.com, Ingo Molnar Subject: [PATCH 3.15 122/122] mm/numa: Remove BUG_ON() in __handle_mm_fault() Date: Mon, 7 Jul 2014 16:58:04 -0700 Message-Id: <20140707235737.894790405@linuxfoundation.org> X-Mailer: git-send-email 2.0.0.254.g50f84e3 In-Reply-To: <20140707235734.234226883@linuxfoundation.org> References: <20140707235734.234226883@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Rik van Riel commit 107437febd495a50e2cd09c81bbaa84d30e57b07 upstream. Changing PTEs and PMDs to pte_numa & pmd_numa is done with the mmap_sem held for reading, which means a pmd can be instantiated and turned into a numa one while __handle_mm_fault() is examining the value of old_pmd. If that happens, __handle_mm_fault() should just return and let the page fault retry, instead of throwing an oops. This is handled by the test for pmd_trans_huge(*pmd) below. Signed-off-by: Rik van Riel Reviewed-by: Naoya Horiguchi Reported-by: Sunil Pandey Signed-off-by: Peter Zijlstra Cc: Andrew Morton Cc: Johannes Weiner Cc: Kirill A. Shutemov Cc: Linus Torvalds Cc: Mel Gorman Cc: linux-mm@kvack.org Cc: lwoodman@redhat.com Cc: dave.hansen@intel.com Link: http://lkml.kernel.org/r/20140429153615.2d72098e@annuminas.surriel.com Signed-off-by: Ingo Molnar Patrick McLean Signed-off-by: Greg Kroah-Hartman --- mm/memory.c | 3 --- 1 file changed, 3 deletions(-) --- a/mm/memory.c +++ b/mm/memory.c @@ -3920,9 +3920,6 @@ static int __handle_mm_fault(struct mm_s } } - /* THP should already have been handled */ - BUG_ON(pmd_numa(*pmd)); - /* * Use __pte_alloc instead of pte_alloc_map, because we can't * run pte_offset_map on the pmd, if an huge pmd could -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/