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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 09818C4321A for ; Fri, 28 Jun 2019 03:12:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D45FF206A2 for ; Fri, 28 Jun 2019 03:12:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726926AbfF1DM4 convert rfc822-to-8bit (ORCPT ); Thu, 27 Jun 2019 23:12:56 -0400 Received: from ozlabs.org ([203.11.71.1]:49101 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726749AbfF1DMz (ORCPT ); Thu, 27 Jun 2019 23:12:55 -0400 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 45ZhfD3QYHz9s3l; Fri, 28 Jun 2019 13:12:52 +1000 (AEST) From: Michael Ellerman To: Qian Cai , "Aneesh Kumar K.V" , Anju T Sudhakar Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: power9 NUMA crash while reading debugfs imc_cmd In-Reply-To: <1561670472.5154.98.camel@lca.pw> References: <1561670472.5154.98.camel@lca.pw> Date: Fri, 28 Jun 2019 13:12:48 +1000 Message-ID: <87lfxms8r3.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Qian Cai writes: > Read of debugfs imc_cmd file for a memory-less node will trigger a crash below > on this power9 machine which has the following NUMA layout. What type of machine is it? cheers > I don't understand why I only saw it recently on linux-next where it > was tested everyday. I can reproduce it back to 4.20 where 4.18 seems > work fine. > > # cat /sys/kernel/debug/powerpc/imc/imc_cmd_252 (On a 4.18-based kernel) > 0x0000000000000000 > > # numactl -H > available: 6 nodes (0,8,252-255) > node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 > 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 > 53 54 55 56 57 58 59 60 61 62 63 > node 0 size: 130210 MB > node 0 free: 128406 MB > node 8 cpus: 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 > 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 > 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 > node 8 size: 130784 MB > node 8 free: 130051 MB > node 252 cpus: > node 252 size: 0 MB > node 252 free: 0 MB > node 253 cpus: > node 253 size: 0 MB > node 253 free: 0 MB > node 254 cpus: > node 254 size: 0 MB > node 254 free: 0 MB > node 255 cpus: > node 255 size: 0 MB > node 255 free: 0 MB > node distances: > node   0   8  252  253  254  255  >   0:  10  40  80  80  80  80  >   8:  40  10  80  80  80  80  >  252:  80  80  10  80  80  80  >  253:  80  80  80  10  80  80  >  254:  80  80  80  80  10  80  >  255:  80  80  80  80  80  10 > > # cat /sys/kernel/debug/powerpc/imc/imc_cmd_252 > > [ 1139.415461][ T5301] Faulting instruction address: 0xc0000000000d0d58 > [ 1139.415492][ T5301] Oops: Kernel access of bad area, sig: 11 [#1] > [ 1139.415509][ T5301] LE PAGE_SIZE=64K MMU=Radix MMU=Hash SMP NR_CPUS=256 > DEBUG_PAGEALLOC NUMA PowerNV > [ 1139.415542][ T5301] Modules linked in: i2c_opal i2c_core ip_tables x_tables > xfs sd_mod bnx2x mdio ahci libahci tg3 libphy libata firmware_class dm_mirror > dm_region_hash dm_log dm_mod > [ 1139.415595][ T5301] CPU: 67 PID: 5301 Comm: cat Not tainted 5.2.0-rc6-next- > 20190627+ #19 > [ 1139.415634][ T5301] NIP:  c0000000000d0d58 LR: c00000000049aa18 CTR: > c0000000000d0d50 > [ 1139.415675][ T5301] REGS: c00020194548f9e0 TRAP: 0300   Not tainted  (5.2.0- > rc6-next-20190627+) > [ 1139.415705][ T5301] MSR:  9000000000009033   CR: > 28022822  XER: 00000000 > [ 1139.415777][ T5301] CFAR: c00000000049aa14 DAR: 000000000003fc08 DSISR: > 40000000 IRQMASK: 0  > [ 1139.415777][ T5301] GPR00: c00000000049aa18 c00020194548fc70 c0000000016f8b00 > 000000000003fc08  > [ 1139.415777][ T5301] GPR04: c00020194548fcd0 0000000000000000 0000000014884e73 > ffffffff00011eaa  > [ 1139.415777][ T5301] GPR08: 000000007eea5a52 c0000000000d0d50 0000000000000000 > 0000000000000000  > [ 1139.415777][ T5301] GPR12: c0000000000d0d50 c000201fff7f8c00 0000000000000000 > 0000000000000000  > [ 1139.415777][ T5301] GPR16: 000000000000000d 00007fffeb0c3368 ffffffffffffffff > 0000000000000000  > [ 1139.415777][ T5301] GPR20: 0000000000000000 0000000000000000 0000000000000000 > 0000000000020000  > [ 1139.415777][ T5301] GPR24: 0000000000000000 0000000000000000 0000000000020000 > 000000010ec90000  > [ 1139.415777][ T5301] GPR28: c00020194548fdf0 c00020049a584ef8 0000000000000000 > c00020049a584ea8  > [ 1139.416116][ T5301] NIP [c0000000000d0d58] imc_mem_get+0x8/0x20 > [ 1139.416143][ T5301] LR [c00000000049aa18] simple_attr_read+0x118/0x170 > [ 1139.416158][ T5301] Call Trace: > [ 1139.416182][ T5301] [c00020194548fc70] [c00000000049a970] > simple_attr_read+0x70/0x170 (unreliable) > [ 1139.416255][ T5301] [c00020194548fd10] [c00000000054385c] > debugfs_attr_read+0x6c/0xb0 > [ 1139.416305][ T5301] [c00020194548fd60] [c000000000454c1c] > __vfs_read+0x3c/0x70 > [ 1139.416363][ T5301] [c00020194548fd80] [c000000000454d0c] vfs_read+0xbc/0x1a0 > [ 1139.416392][ T5301] [c00020194548fdd0] [c00000000045519c] > ksys_read+0x7c/0x140 > [ 1139.416434][ T5301] [c00020194548fe20] [c00000000000b108] > system_call+0x5c/0x70 > [ 1139.416473][ T5301] Instruction dump: > [ 1139.416511][ T5301] 4e800020 60000000 7c0802a6 60000000 7c801d28 38600000 > 4e800020 60000000  > [ 1139.416572][ T5301] 60000000 60000000 7c0802a6 60000000 <7d201c28> 38600000 > f9240000 4e800020  > [ 1139.416636][ T5301] ---[ end trace c44d1fb4ace04784 ]--- > [ 1139.520686][ T5301]  > [ 1140.520820][ T5301] Kernel panic - not syncing: Fatal exception