From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f48.google.com (mail-pa0-f48.google.com [209.85.220.48]) by kanga.kvack.org (Postfix) with ESMTP id CD08C6B003B for ; Mon, 7 Jul 2014 19:54:26 -0400 (EDT) Received: by mail-pa0-f48.google.com with SMTP id et14so6250840pad.21 for ; Mon, 07 Jul 2014 16:54:26 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id bg5si5384557pdb.468.2014.07.07.16.54.24 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 07 Jul 2014 16:54:25 -0700 (PDT) From: Greg Kroah-Hartman 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> In-Reply-To: <20140707235734.234226883@linuxfoundation.org> References: <20140707235734.234226883@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: 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 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, 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