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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 E5DF3C43441 for ; Tue, 27 Nov 2018 14:36:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BAA52208E4 for ; Tue, 27 Nov 2018 14:36:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BAA52208E4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=de.ibm.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 S1728127AbeK1Bey (ORCPT ); Tue, 27 Nov 2018 20:34:54 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:35694 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726872AbeK1Bey (ORCPT ); Tue, 27 Nov 2018 20:34:54 -0500 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id wAREY5lL103286 for ; Tue, 27 Nov 2018 09:36:47 -0500 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0b-001b2d01.pphosted.com with ESMTP id 2p16r9ka37-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 27 Nov 2018 09:36:46 -0500 Received: from localhost by e06smtp01.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 27 Nov 2018 14:36:44 -0000 Received: from b06cxnps4074.portsmouth.uk.ibm.com (9.149.109.196) by e06smtp01.uk.ibm.com (192.168.101.131) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 27 Nov 2018 14:36:41 -0000 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id wAREae2C5636430 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 27 Nov 2018 14:36:40 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 7565811C04A; Tue, 27 Nov 2018 14:36:40 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 2DF4211C04C; Tue, 27 Nov 2018 14:36:40 +0000 (GMT) Received: from osiris (unknown [9.152.212.95]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Tue, 27 Nov 2018 14:36:40 +0000 (GMT) Date: Tue, 27 Nov 2018 15:36:38 +0100 From: Heiko Carstens To: Michal Hocko Cc: Andrew Morton , linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, linux-mm@kvack.org, "Kirill A . Shutemov" , Martin Schwidefsky Subject: Re: [PATCH] mm: warn only once if page table misaccounting is detected References: <20181127083603.39041-1-heiko.carstens@de.ibm.com> <20181127131916.GX12455@dhcp22.suse.cz> MIME-Version: 1.0 In-Reply-To: <20181127131916.GX12455@dhcp22.suse.cz> X-TM-AS-GCONF: 00 x-cbid: 18112714-4275-0000-0000-000002E77989 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18112714-4276-0000-0000-000037F4B6CC Message-Id: <20181127143638.GE3625@osiris> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit Content-Disposition: inline X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-11-27_13:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1811270126 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 27, 2018 at 02:19:16PM +0100, Michal Hocko wrote: > On Tue 27-11-18 09:36:03, Heiko Carstens wrote: > > Use pr_alert_once() instead of pr_alert() if page table misaccounting > > has been detected. > > > > If this happens once it is very likely that there will be numerous > > other occurrence as well, which would flood dmesg and the console with > > hardly any added information. Therefore print the warning only once. > > Have you actually experience a flood of these messages? Is one per mm > message really that much? Yes, I did. Since in this case all compat processes caused the message to appear, I saw thousands of these messages. > If yes why rss counters do not exhibit the same problem? No rss counter messages appeared. Or do you suggest that the other pr_alert() within check_mm() should also be changed?