From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 713A0C43441 for ; Thu, 29 Nov 2018 13:51:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 37BE420863 for ; Thu, 29 Nov 2018 13:51:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="a0evLdla" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 37BE420863 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=oracle.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728341AbeK3A5E (ORCPT ); Thu, 29 Nov 2018 19:57:04 -0500 Received: from userp2120.oracle.com ([156.151.31.85]:57498 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726949AbeK3A5E (ORCPT ); Thu, 29 Nov 2018 19:57:04 -0500 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.22/8.16.0.22) with SMTP id wATDnTZn194140; Thu, 29 Nov 2018 13:51:34 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=content-type : mime-version : subject : from : in-reply-to : date : cc : content-transfer-encoding : message-id : references : to; s=corp-2018-07-02; bh=lZIasuT6Y6xpvBsQWZEcTUxxsQfR5vQV9qb6Ra4P6Es=; b=a0evLdlazr4iLg2S5BaeRdPQm77yxEolv4LlyfscmKPMsmEc4IUW+76imUBGB+py7M3t tNflNQb3zJruWz0DAmTI6AlDuoGBRl1adQdvP+S0QazgnBxruo3lmccJzFVNeemWtNT8 Tiu/j7CR3YGzlf18d6mZb7FHAFB5VRkQpQgubnf8QkzLh7bmdSuCF6VllcZ7XqUumfM8 GUZ1azMxn1KHn+Fa3CcQx/n/kvu68bQVayaJw/i8LTI4kAPCLaMV+YPog7FLMAW4TgRO Y3vi7Kr4OcOqQASnx85U9sP/hnUWRFHJ/yYVmGZwC2eQreeoBOnApwgrcwYUZp4DDPxj Yg== Received: from aserv0022.oracle.com (aserv0022.oracle.com [141.146.126.234]) by userp2120.oracle.com with ESMTP id 2nxy9rg7ve-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 29 Nov 2018 13:51:34 +0000 Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by aserv0022.oracle.com (8.14.4/8.14.4) with ESMTP id wATDpX85030498 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 29 Nov 2018 13:51:33 GMT Received: from abhmp0007.oracle.com (abhmp0007.oracle.com [141.146.116.13]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id wATDpWnt031913; Thu, 29 Nov 2018 13:51:32 GMT Received: from [192.168.0.110] (/73.243.10.6) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 29 Nov 2018 05:51:32 -0800 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 12.2 \(3445.102.3\)) Subject: Re: [PATCH] hugetlbfs: Call VM_BUG_ON_PAGE earlier in free_huge_page From: William Kucharski In-Reply-To: <1543491843-23438-1-git-send-email-nic_w@163.com> Date: Thu, 29 Nov 2018 06:51:28 -0700 Cc: mike.kravetz@oracle.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, nic_w@163.com Content-Transfer-Encoding: 7bit Message-Id: <0B408D50-D101-4457-B779-5951DEE0435A@oracle.com> References: <1543491843-23438-1-git-send-email-nic_w@163.com> To: Yongkai Wu X-Mailer: Apple Mail (2.3445.102.3) X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9091 signatures=668686 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=2 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1811290117 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Reviewed-by: William Kucharski > On Nov 29, 2018, at 4:44 AM, Yongkai Wu wrote: > > A stack trace was triggered by VM_BUG_ON_PAGE(page_mapcount(page), > page) in free_huge_page(). Unfortunately, the page->mapping field > was set to NULL before this test. This made it more difficult to > determine the root cause of the problem. > > Move the VM_BUG_ON_PAGE tests earlier in the function so that if > they do trigger more information is present in the page struct. > > Signed-off-by: Yongkai Wu > Acked-by: Michal Hocko > Acked-by: Mike Kravetz > --- > mm/hugetlb.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 7f2a28a..14ef274 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -1248,10 +1248,11 @@ void free_huge_page(struct page *page) > (struct hugepage_subpool *)page_private(page); > bool restore_reserve; > > - set_page_private(page, 0); > - page->mapping = NULL; > VM_BUG_ON_PAGE(page_count(page), page); > VM_BUG_ON_PAGE(page_mapcount(page), page); > + > + set_page_private(page, 0); > + page->mapping = NULL; > restore_reserve = PagePrivate(page); > ClearPagePrivate(page); > > -- > 1.8.3.1 >