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,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 869CCC43441 for ; Sun, 11 Nov 2018 11:36:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 03144208A3 for ; Sun, 11 Nov 2018 11:36:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 03144208A3 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 S1727874AbeKKVYX (ORCPT ); Sun, 11 Nov 2018 16:24:23 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:44964 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727440AbeKKVYW (ORCPT ); Sun, 11 Nov 2018 16:24:22 -0500 Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id wABBSods105059 for ; Sun, 11 Nov 2018 06:36:03 -0500 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0a-001b2d01.pphosted.com with ESMTP id 2npdv7awww-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Sun, 11 Nov 2018 06:36:02 -0500 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Sun, 11 Nov 2018 11:35:56 -0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id wABBZt5Q65601670 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Sun, 11 Nov 2018 11:35:56 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D4E864C044; Sun, 11 Nov 2018 11:35:55 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 97F334C040; Sun, 11 Nov 2018 11:35:55 +0000 (GMT) Received: from mschwideX1 (unknown [9.145.75.196]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Sun, 11 Nov 2018 11:35:55 +0000 (GMT) Date: Sun, 11 Nov 2018 12:35:53 +0100 From: Martin Schwidefsky To: Qian Cai Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, "Kirill A. Shutemov" Subject: Re: crashkernel=512M is no longer working on this aarch64 server In-Reply-To: <1A7E2E89-34DB-41A0-BBA2-323073A7E298@gmx.us> References: <1A7E2E89-34DB-41A0-BBA2-323073A7E298@gmx.us> X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 X-TM-AS-GCONF: 00 x-cbid: 18111111-0020-0000-0000-000002E63B2C X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18111111-0021-0000-0000-000021353CB0 Message-Id: <20181111123553.3a35a15c@mschwideX1> Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8bit X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-11-11_08:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=783 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1811110111 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 10 Nov 2018 23:41:34 -0500 Qian Cai wrote: > It was broken somewhere between b00d209241ff and 3541833fd1f2. > > [ 0.000000] cannot allocate crashkernel (size:0x20000000) > > Where a good one looks like this, > > [ 0.000000] crashkernel reserved: 0x0000000008600000 - 0x0000000028600000 (512 MB) > > Some commits look more suspicious than others. > > mm: add mm_pxd_folded checks to pgtable_bytes accounting functions > mm: introduce mm_[p4d|pud|pmd]_folded > mm: make the __PAGETABLE_PxD_FOLDED defines non-empty The intent of these three patches is to add extra checks to the pgtable_bytes accounting function. If applied incorrectly the expected result would be warnings like this: BUG: non-zero pgtables_bytes on freeing mm: 16384 The change Linus worried about affects the __PAGETABLE_PxD_FOLDED defines. These defines are used with #ifdef, #ifndef, and __is_defined() for the new mm_p?d_folded() macros. I can not see how this would make a difference for your iomem setup. > # diff -u ../iomem.good.txt ../iomem.bad.txt > --- ../iomem.good.txt 2018-11-10 22:28:20.092614398 -0500 > +++ ../iomem.bad.txt 2018-11-10 20:39:54.930294479 -0500 > @@ -1,9 +1,8 @@ > 00000000-3965ffff : System RAM > 00080000-018cffff : Kernel code > - 018d0000-020affff : reserved > - 020b0000-045affff : Kernel data > - 08600000-285fffff : Crash kernel > - 28730000-2d5affff : reserved > + 018d0000-0762ffff : reserved > + 07630000-09b2ffff : Kernel data > + 231b0000-2802ffff : reserved > 30ec0000-30ecffff : reserved > 35660000-3965ffff : reserved > 39660000-396fffff : reserved > @@ -127,7 +126,7 @@ > 7c5200000-7c520ffff : 0004:48:00.0 > 1040000000-17fbffffff : System RAM > 13fbfd0000-13fdfdffff : reserved > - 16fba80000-17fbfdffff : reserved > + 16fafd0000-17fbfdffff : reserved > 17fbfe0000-17fbffffff : reserved > 1800000000-1ffbffffff : System RAM > 1bfbff0000-1bfdfeffff : reserved The easiest way to verify if the three commits have something to do with your problem is to revert them and run your test. Can you do that please ? -- blue skies, Martin. "Reality continues to ruin my life." - Calvin.