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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 8DC33C433E2 for ; Mon, 1 Jun 2020 19:31:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5FE9520734 for ; Mon, 1 Jun 2020 19:31:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="YU+K2dn0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728408AbgFATbe (ORCPT ); Mon, 1 Jun 2020 15:31:34 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:46052 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728336AbgFATbd (ORCPT ); Mon, 1 Jun 2020 15:31:33 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 051JHsYY033505; Mon, 1 Jun 2020 19:30:47 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=corp-2020-01-29; bh=99bX7LbE/rd0UoEHl5ZkNlsl3nd8u3xm14xHmfAdCYk=; b=YU+K2dn0E48mqXOCiE2qY+6sgC5QYCcb5T+JxrrbKcSUIFTVynebpV8pbcpQSvfposea 1xQcJwi0pnKZmZmOg+VGP0Cw0JncuflWH685YjSp8sOLn/RnFgoJF3AGr3Vc/32cPPNW CnD2Pzorh4/PS2umNO6qFJ3+nGaDcEDADmywHqCdFwVJvz7g8Lof+BhYsQymymUfFwXF /YO6vxmA75hoJdap58yGRWFQL8yJqUA5NaMw1mcLIJsvNZ4VBoRUZOlRbZP7Dgb85q+P ON90Sm4eajuwdBlbeQZGimARG8EWSZfRlo6fh/sI1ns7QIzzEq6NuthnwLIoiKNzMAsZ iw== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by userp2130.oracle.com with ESMTP id 31bewqrgsc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 01 Jun 2020 19:30:46 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 051JHrV7087956; Mon, 1 Jun 2020 19:30:46 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by aserp3020.oracle.com with ESMTP id 31c25kjhq7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 01 Jun 2020 19:30:46 +0000 Received: from abhmp0005.oracle.com (abhmp0005.oracle.com [141.146.116.11]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 051JUaaq016865; Mon, 1 Jun 2020 19:30:36 GMT Received: from [192.168.1.106] (/47.220.71.223) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 01 Jun 2020 12:30:36 -0700 Subject: Re: [PATCH v8 0/5] support reserving crashkernel above 4G on arm64 kdump To: Prabhakar Kushwaha , Chen Zhou Cc: Thomas Gleixner , mingo@redhat.com, Catalin Marinas , Will Deacon , dyoung@redhat.com, bhe@redhat.com, robh+dt@kernel.org, arnd@arndb.de, devicetree@vger.kernel.org, Linux Doc Mailing List , kexec mailing list , Linux Kernel Mailing List , horms@verge.net.au, guohanjun@huawei.com, Prabhakar Kushwaha , linux-arm-kernel , James Morse References: <20200521093805.64398-1-chenzhou10@huawei.com> From: John Donnelly Message-ID: <303695cc-d3ea-9f51-1489-07d27d4253d4@oracle.com> Date: Mon, 1 Jun 2020 14:30:34 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9639 signatures=668686 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 suspectscore=0 spamscore=0 malwarescore=0 bulkscore=0 mlxscore=0 phishscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006010142 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9639 signatures=668686 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 bulkscore=0 phishscore=0 suspectscore=0 impostorscore=0 cotscore=-2147483648 lowpriorityscore=0 mlxscore=0 adultscore=0 spamscore=0 mlxlogscore=999 malwarescore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006010142 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 6/1/20 7:02 AM, Prabhakar Kushwaha wrote: > Hi Chen, > > On Thu, May 21, 2020 at 3:05 PM Chen Zhou wrote: >> This patch series enable reserving crashkernel above 4G in arm64. >> >> There are following issues in arm64 kdump: >> 1. We use crashkernel=X to reserve crashkernel below 4G, which will fail >> when there is no enough low memory. >> 2. Currently, crashkernel=Y@X can be used to reserve crashkernel above 4G, >> in this case, if swiotlb or DMA buffers are required, crash dump kernel >> will boot failure because there is no low memory available for allocation. >> >> To solve these issues, introduce crashkernel=X,low to reserve specified >> size low memory. >> Crashkernel=X tries to reserve memory for the crash dump kernel under >> 4G. If crashkernel=Y,low is specified simultaneously, reserve spcified >> size low memory for crash kdump kernel devices firstly and then reserve >> memory above 4G. >> >> When crashkernel is reserved above 4G in memory, that is, crashkernel=X,low >> is specified simultaneously, kernel should reserve specified size low memory >> for crash dump kernel devices. So there may be two crash kernel regions, one >> is below 4G, the other is above 4G. >> In order to distinct from the high region and make no effect to the use of >> kexec-tools, rename the low region as "Crash kernel (low)", and add DT property >> "linux,low-memory-range" to crash dump kernel's dtb to pass the low region. >> >> Besides, we need to modify kexec-tools: >> arm64: kdump: add another DT property to crash dump kernel's dtb(see [1]) >> >> The previous changes and discussions can be retrieved from: >> >> Changes since [v7] >> - Move x86 CRASH_ALIGN to 2M >> Suggested by Dave and do some test, move x86 CRASH_ALIGN to 2M. >> - Update Documentation/devicetree/bindings/chosen.txt >> Add corresponding documentation to Documentation/devicetree/bindings/chosen.txt suggested by Arnd. >> - Add Tested-by from Jhon and pk >> >> Changes since [v6] >> - Fix build errors reported by kbuild test robot. >> >> Changes since [v5] >> - Move reserve_crashkernel_low() into kernel/crash_core.c. >> - Delete crashkernel=X,high. >> - Modify crashkernel=X,low. >> If crashkernel=X,low is specified simultaneously, reserve spcified size low >> memory for crash kdump kernel devices firstly and then reserve memory above 4G. >> In addition, rename crashk_low_res as "Crash kernel (low)" for arm64, and then >> pass to crash dump kernel by DT property "linux,low-memory-range". >> - Update Documentation/admin-guide/kdump/kdump.rst. >> >> Changes since [v4] >> - Reimplement memblock_cap_memory_ranges for multiple ranges by Mike. >> >> Changes since [v3] >> - Add memblock_cap_memory_ranges back for multiple ranges. >> - Fix some compiling warnings. >> >> Changes since [v2] >> - Split patch "arm64: kdump: support reserving crashkernel above 4G" as >> two. Put "move reserve_crashkernel_low() into kexec_core.c" in a separate >> patch. >> >> Changes since [v1]: >> - Move common reserve_crashkernel_low() code into kernel/kexec_core.c. >> - Remove memblock_cap_memory_ranges() i added in v1 and implement that >> in fdt_enforce_memory_region(). >> There are at most two crash kernel regions, for two crash kernel regions >> case, we cap the memory range [min(regs[*].start), max(regs[*].end)] >> and then remove the memory range in the middle. >> >> [1]: https://urldefense.com/v3/__http://lists.infradead.org/pipermail/kexec/2020-May/025128.html__;!!GqivPVa7Brio!LnTSARkCt0V0FozR0KmqooaH5ADtdXvs3mPdP3KRVqALmvSK2VmCkIPIhsaxbvpn1uM1$ >> [v1]: https://urldefense.com/v3/__https://lkml.org/lkml/2019/4/2/1174__;!!GqivPVa7Brio!LnTSARkCt0V0FozR0KmqooaH5ADtdXvs3mPdP3KRVqALmvSK2VmCkIPIhsaxbt0xN9PE$ >> [v2]: https://urldefense.com/v3/__https://lkml.org/lkml/2019/4/9/86__;!!GqivPVa7Brio!LnTSARkCt0V0FozR0KmqooaH5ADtdXvs3mPdP3KRVqALmvSK2VmCkIPIhsaxbub7yUQH$ >> [v3]: https://urldefense.com/v3/__https://lkml.org/lkml/2019/4/9/306__;!!GqivPVa7Brio!LnTSARkCt0V0FozR0KmqooaH5ADtdXvs3mPdP3KRVqALmvSK2VmCkIPIhsaxbnc4zPPV$ >> [v4]: https://urldefense.com/v3/__https://lkml.org/lkml/2019/4/15/273__;!!GqivPVa7Brio!LnTSARkCt0V0FozR0KmqooaH5ADtdXvs3mPdP3KRVqALmvSK2VmCkIPIhsaxbvsAsZLu$ >> [v5]: https://urldefense.com/v3/__https://lkml.org/lkml/2019/5/6/1360__;!!GqivPVa7Brio!LnTSARkCt0V0FozR0KmqooaH5ADtdXvs3mPdP3KRVqALmvSK2VmCkIPIhsaxbl24n-79$ >> [v6]: https://urldefense.com/v3/__https://lkml.org/lkml/2019/8/30/142__;!!GqivPVa7Brio!LnTSARkCt0V0FozR0KmqooaH5ADtdXvs3mPdP3KRVqALmvSK2VmCkIPIhsaxbs7r8G2a$ >> [v7]: https://urldefense.com/v3/__https://lkml.org/lkml/2019/12/23/411__;!!GqivPVa7Brio!LnTSARkCt0V0FozR0KmqooaH5ADtdXvs3mPdP3KRVqALmvSK2VmCkIPIhsaxbiFUH90G$ >> >> Chen Zhou (5): >> x86: kdump: move reserve_crashkernel_low() into crash_core.c >> arm64: kdump: reserve crashkenel above 4G for crash dump kernel >> arm64: kdump: add memory for devices by DT property, low-memory-range >> kdump: update Documentation about crashkernel on arm64 >> dt-bindings: chosen: Document linux,low-memory-range for arm64 kdump >> > We are getting "warn_alloc" [1] warning during boot of kdump kernel > with bootargs as [2] of primary kernel. > This error observed on ThunderX2 ARM64 platform. > > It is observed with latest upstream tag (v5.7-rc3) with this patch set > and https://urldefense.com/v3/__https://lists.infradead.org/pipermail/kexec/2020-May/025128.html__;!!GqivPVa7Brio!LnTSARkCt0V0FozR0KmqooaH5ADtdXvs3mPdP3KRVqALmvSK2VmCkIPIhsaxbiIAAlzu$ > Also **without** this patch-set > "https://urldefense.com/v3/__https://www.spinics.net/lists/arm-kernel/msg806882.html__;!!GqivPVa7Brio!LnTSARkCt0V0FozR0KmqooaH5ADtdXvs3mPdP3KRVqALmvSK2VmCkIPIhsaxbjC6ujMA$" > > This issue comes whenever crashkernel memory is reserved after 0xc000_0000. > More details discussed earlier in > https://urldefense.com/v3/__https://www.spinics.net/lists/arm-kernel/msg806882.html__;!!GqivPVa7Brio!LnTSARkCt0V0FozR0KmqooaH5ADtdXvs3mPdP3KRVqALmvSK2VmCkIPIhsaxbjC6ujMA$ without any > solution > > This patch-set is expected to solve similar kind of issue. > i.e. low memory is only targeted for DMA, swiotlb; So above mentioned > observation should be considered/fixed. . > > --pk > > [1] > [ 30.366695] DMI: Cavium Inc. Saber/Saber, BIOS > TX2-FW-Release-3.1-build_01-2803-g74253a541a mm/dd/yyyy > [ 30.367696] NET: Registered protocol family 16 > [ 30.369973] swapper/0: page allocation failure: order:6, > mode:0x1(GFP_DMA), nodemask=(null),cpuset=/,mems_allowed=0 > [ 30.369980] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.7.0-rc3+ #121 > [ 30.369981] Hardware name: Cavium Inc. Saber/Saber, BIOS > TX2-FW-Release-3.1-build_01-2803-g74253a541a mm/dd/yyyy > [ 30.369984] Call trace: > [ 30.369989] dump_backtrace+0x0/0x1f8 > [ 30.369991] show_stack+0x20/0x30 > [ 30.369997] dump_stack+0xc0/0x10c > [ 30.370001] warn_alloc+0x10c/0x178 > [ 30.370004] __alloc_pages_slowpath.constprop.111+0xb10/0xb50 > [ 30.370006] __alloc_pages_nodemask+0x2b4/0x300 > [ 30.370008] alloc_page_interleave+0x24/0x98 > [ 30.370011] alloc_pages_current+0xe4/0x108 > [ 30.370017] dma_atomic_pool_init+0x44/0x1a4 > [ 30.370020] do_one_initcall+0x54/0x228 > [ 30.370027] kernel_init_freeable+0x228/0x2cc > [ 30.370031] kernel_init+0x1c/0x110 > [ 30.370034] ret_from_fork+0x10/0x18 > [ 30.370036] Mem-Info: > [ 30.370064] active_anon:0 inactive_anon:0 isolated_anon:0 > [ 30.370064] active_file:0 inactive_file:0 isolated_file:0 > [ 30.370064] unevictable:0 dirty:0 writeback:0 unstable:0 > [ 30.370064] slab_reclaimable:34 slab_unreclaimable:4438 > [ 30.370064] mapped:0 shmem:0 pagetables:14 bounce:0 > [ 30.370064] free:1537719 free_pcp:219 free_cma:0 > [ 30.370070] Node 0 active_anon:0kB inactive_anon:0kB > active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB > isolated(file):0kB mapped:0kB dirty:0kB writeback:0kB shmem:0kB > shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 0kB writeback_tmp:0kB > unstable:0kB all_unreclaimable? no > [ 30.370073] Node 1 active_anon:0kB inactive_anon:0kB > active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB > isolated(file):0kB mapped:0kB dirty:0kB writeback:0kB shmem:0kB > shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 0kB writeback_tmp:0kB > unstable:0kB all_unreclaimable? no > [ 30.370079] Node 0 DMA free:0kB min:0kB low:0kB high:0kB > reserved_highatomic:0KB active_anon:0kB inactive_anon:0kB > active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB > present:128kB managed:0kB mlocked:0kB kernel_stack:0kB pagetables:0kB > bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB > [ 30.370084] lowmem_reserve[]: 0 250 6063 6063 > [ 30.370090] Node 0 DMA32 free:256000kB min:408kB low:664kB > high:920kB reserved_highatomic:0KB active_anon:0kB inactive_anon:0kB > active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB > present:269700kB managed:256000kB mlocked:0kB kernel_stack:0kB > pagetables:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB > [ 30.370094] lowmem_reserve[]: 0 0 5813 5813 > [ 30.370100] Node 0 Normal free:5894876kB min:9552kB low:15504kB > high:21456kB reserved_highatomic:0KB active_anon:0kB inactive_anon:0kB > active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB > present:8388608kB managed:5953112kB mlocked:0kB kernel_stack:21672kB > pagetables:56kB bounce:0kB free_pcp:876kB local_pcp:176kB free_cma:0kB > [ 30.370104] lowmem_reserve[]: 0 0 0 0 > [ 30.370107] Node 0 DMA: 0*4kB 0*8kB 0*16kB 0*32kB 0*64kB 0*128kB > 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 0kB > [ 30.370113] Node 0 DMA32: 0*4kB 0*8kB 0*16kB 0*32kB 0*64kB 0*128kB > 0*256kB 0*512kB 0*1024kB 1*2048kB (M) 62*4096kB (M) = 256000kB > [ 30.370119] Node 0 Normal: 2*4kB (M) 3*8kB (ME) 2*16kB (UE) 3*32kB > (UM) 1*64kB (U) 2*128kB (M) 2*256kB (ME) 3*512kB (ME) 3*1024kB (ME) > 3*2048kB (UME) 1436*4096kB (M) = 5893600kB > [ 30.370129] Node 0 hugepages_total=0 hugepages_free=0 > hugepages_surp=0 hugepages_size=1048576kB > [ 30.370130] 0 total pagecache pages > [ 30.370132] 0 pages in swap cache > [ 30.370134] Swap cache stats: add 0, delete 0, find 0/0 > [ 30.370135] Free swap = 0kB > [ 30.370136] Total swap = 0kB > [ 30.370137] 2164609 pages RAM > [ 30.370139] 0 pages HighMem/MovableOnly > [ 30.370140] 612331 pages reserved > [ 30.370141] 0 pages hwpoisoned > [ 30.370143] DMA: failed to allocate 256 KiB pool for atomic > coherent allocation During my testing I saw the same error and Chen's  solution corrected it .