------- Comment From ferse...@br.ibm.com 2017-02-01 14:30 EDT------- I have added the workaround to recommendations in our wiki page at:
https://wiki.ubuntu.com/ppc64el/Recommendations#Kdump_not_generating_crash_dump_file Please check it out and let me know if it looks ok. Cheers -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1635063 Title: Ubuntu 16.10: System hangs after crash on Ubuntu KVM guest. Status in linux package in Ubuntu: New Bug description: ---Problem Description--- Ubuntu 16.10: System hangs after crash on Ubuntu KVM guest. ---Steps to Reproduce--- 1) apt-get install linux-crashdump 2) increase crashdump size: sudo vim /etc/default/grub.d/kexec-tools.cfg GRUB_CMDLINE_LINUX_DEFAULT="$GRUB_CMDLINE_LINUX_DEFAULT crashkernel =2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M" 3) sudo update-grub ; reboot the machine 4) sudo sed -i 's/USE_KDUMP=0/USE_KDUMP=1/g' /etc/default/kdump-tools 5) kdump-config show 6) echo "c" > /proc/sysrq-trigger Logs ==== root@ubuntu:/var/crash# uname -a Linux ubuntu 4.8.0-17-generic #19-Ubuntu SMP Sun Sep 25 06:35:40 UTC 2016 ppc64le ppc64le ppc64le GNU/Linux root@ubuntu:/var/crash# kdump-config show DUMP_MODE: kdump USE_KDUMP: 1 KDUMP_SYSCTL: kernel.panic_on_oops=1 KDUMP_COREDIR: /var/crash crashkernel addr: /var/lib/kdump/vmlinuz: symbolic link to /boot/vmlinux-4.8.0-17-generic kdump initrd: /var/lib/kdump/initrd.img: symbolic link to /var/lib/kdump/initrd.img-4.8.0-17-generic current state: ready to kdump kexec command: /sbin/kexec -p --command-line="BOOT_IMAGE=/boot/vmlinux-4.8.0-17-generic root=UUID=70f3c690-fe90-444d-a74c-71c05eef8b0e ro splash quiet irqpoll nr_cpus=1 nousb systemd.unit=kdump-tools.service" --initrd=/var/lib/kdump/initrd.img /var/lib/kdump/vmlinuz root@ubuntu:/var/crash# echo c > /proc/sysrq-trigger [ 202.677946] sysrq: SysRq : Trigger a crash [ 202.678018] Unable to handle kernel paging request for data at address 0x00000000 [ 202.678098] Faulting instruction address: 0xc0000000006de134 [ 202.678169] Oops: Kernel access of bad area, sig: 11 [#1] [ 202.678222] SMP NR_CPUS=2048 NUMA pSeries [ 202.678281] Modules linked in: vmx_crypto ip_tables x_tables autofs4 ibmvscsi crc32c_vpmsum 8139too 8139cp mii [ 202.678465] CPU: 3 PID: 1992 Comm: bash Not tainted 4.8.0-17-generic #19-Ubuntu [ 202.678547] task: c000000004c5ce00 task.stack: c00000000428c000 [ 202.678612] NIP: c0000000006de134 LR: c0000000006df218 CTR: c0000000006de100 [ 202.678716] REGS: c00000000428f990 TRAP: 0300 Not tainted (4.8.0-17-generic) [ 202.678796] MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 28242222 XER: 20000000 [ 202.678992] CFAR: c000000000014f84 DAR: 0000000000000000 DSISR: 42000000 SOFTE: 1 GPR00: c0000000006df218 c00000000428fc10 c0000000014e5e00 0000000000000063 GPR04: c00000007fecaca0 c00000007fedfb40 c00000000168d278 0000000000004b78 GPR08: 0000000000000007 0000000000000001 0000000000000000 0000000000000001 GPR12: c0000000006de100 c000000007b81b00 ffffffffffffffff 0000000022000000 GPR16: 0000000010170dc8 0000010020c60488 0000000010140f58 00000000100c7570 GPR20: 0000000000000000 000000001017dd58 0000000010153618 000000001017b608 GPR24: 00003fffd5f377c4 0000000000000001 c0000000013fe5d0 0000000000000004 GPR28: c0000000013fe990 0000000000000063 c0000000013b2590 0000000000000000 [ 202.680090] NIP [c0000000006de134] sysrq_handle_crash+0x34/0x50 [ 202.680159] LR [c0000000006df218] __handle_sysrq+0xe8/0x280 [ 202.680213] Call Trace: [ 202.680246] [c00000000428fc10] [c000000000e79720] _fw_tigon_tg3_bin_name+0x2f1a8/0x36f48 (unreliable) [ 202.680356] [c00000000428fc30] [c0000000006df218] __handle_sysrq+0xe8/0x280 [ 202.680440] [c00000000428fcd0] [c0000000006df9c8] write_sysrq_trigger+0x78/0xa0 [ 202.680535] [c00000000428fd00] [c0000000003cf890] proc_reg_write+0xb0/0x110 [ 202.680618] [c00000000428fd50] [c00000000032b5dc] __vfs_write+0x6c/0xe0 [ 202.680702] [c00000000428fd90] [c00000000032cae4] vfs_write+0xd4/0x240 [ 202.680783] [c00000000428fde0] [c00000000032e7fc] SyS_write+0x6c/0x110 [ 202.680867] [c00000000428fe30] [c000000000009584] system_call+0x38/0xec [ 202.680948] Instruction dump: [ 202.680991] 38427d00 7c0802a6 f8010010 f821ffe1 60000000 60000000 3d22001a 3949d1e0 [ 202.681133] 39200001 912a0000 7c0004ac 39400000 <992a0000> 38210020 e8010010 7c0803a6 [ 202.681276] ---[ end trace 3e9cbc319000fff4 ]--- [ 202.684658] [ 202.684718] Sending IPI to other CPUs [ 202.686765] IPI complete I'm in purgatory -> smp_release_cpus() spinning_secondaries = 3 <- smp_release_cpus() Linux ppc64le #19-Ubuntu SMP S[ 242.661649] INFO: task swapper/0:1 blocked for more than 120 seconds. [ 242.661708] Not tainted 4.8.0-17-generic #19-Ubuntu [ 242.661746] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 363.493648] INFO: task swapper/0:1 blocked for more than 120 seconds. [ 363.493712] Not tainted 4.8.0-17-generic #19-Ubuntu [ 363.493755] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 484.325651] INFO: task swapper/0:1 blocked for more than 120 seconds. [ 484.325704] Not tainted 4.8.0-17-generic #19-Ubuntu [ 484.325738] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 605.157653] INFO: task swapper/0:1 blocked for more than 120 seconds. [ 605.157712] Not tainted 4.8.0-17-generic #19-Ubuntu [ 605.157750] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 725.989649] INFO: task swapper/0:1 blocked for more than 120 seconds. Observing hang in scheduler while booting kdump kernel with "nr_cpus=1" on KVM guest. [c00000001a06aeb0] [c00000000801ac1c] __switch_to+0x29c/0x420 [c00000001a06af10] [c000000008b8c414] __schedule+0x2f4/0x9b0 [c00000001a06aff0] [c000000008b8cb18] schedule+0x48/0xc0 Need to debug further to find the root cause. The issue is not seen with "maxcpus=1" parameter. As a workaround, please use "maxcpus=1" instead of "nr_cpus=1" for other kdump tests.. Thanks Hari To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1635063/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
