------- Comment From dieg...@br.ibm.com 2017-11-27 06:16 EDT------- (In reply to comment #11) > The problem seems to be related to how qemu allocates the virtual cores and > threads to the VM. > > Starting the VMs with the following command I cannot reproduce the issue: > > $ qemu-system-ppc64le -m 1024 -smp 16,threads=8 -nographic -net > nic,model=virtio -net user,hostfwd=tcp::10022-:22 -drive > file=./autopkgtest-xenial-ppc64el.img -enable-kvm > > As long the number of cpus and threads provided to the -smp parameter follow > the topology of the p8 processor, making qemu use more than one core only if > the number of threads is multiple of 8, I can't reproduce the hang. If the > parameters provided makes qemu spread the virtual threads on more than one > physical cpu without using all the 8 threads (e.g. '-smp 2', '-smp > 4,threads=2', '-smp 8,threads=4') then the guest kernel hangs at some point. > > This is the environment being tested: > > Machine type-model: 8247-22L > > Host: Artful > kernel 4.13.0-17-generic > qemu 2.10+dfsg-0ubuntu3 > > Guests: Xenial, Zesty and Artful with latest kernel from -updates. > > Could someone from IBM please confirm if this is a known or expected > behavior? This issue seems to be around for a long time and it's odd that > this hasn't come up before.
I was not able to reproduce this issue with the following command and environment: $ /usr/libexec/qemu-kvm -hda /home/libvirt-images/diegodo/diegodo- ubuntu16.qcow2 -boot c -net nic -net user -m 512 -localtime -nographic -smp 4,threads=2 HOST: Rhel 7.3 kernel: 4.13.0-rc4 qemu: 2.6.0 -- 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/1733864 Title: kernel 4.10.0-40 is hanging with a CPU soft lock Status in The Ubuntu-power-systems project: New Status in linux package in Ubuntu: In Progress Bug description: Kernel 4.10.0-40-generic is causing CPU hung on POWER machines. I got this problem on a POWER8 KVM virtual machine [ 1912.003255] NMI watchdog: BUG: soft lockup - CPU#12 stuck for 24s! [dpkg-deb:31284] [ 1912.004496] Modules linked in: ufs qnx4 hfsplus hfs minix ntfs msdos jfs xfs ipt_REJECT nf_reject_ipv4 xfrm_user xfrm_algo xt_addrtype xt_conntrack br_netfilter ebtable_filter ebtables ip6table_filter ip6_tables ib_srpt dm_thin_pool dm_persistent_data dm_bio_prison dm_bufio tcm_qla2xxx qla2xxx vhost_scsi vhost usb_f_tcm tcm_usb_gadget libcomposite udc_core tcm_fc libfc scsi_transport_fc tcm_loop iscsi_target_mod target_core_file target_core_iblock target_core_pscsi target_core_mod ipmi_devintf ipmi_msghandler xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat xt_tcpudp iptable_filter ip_tables x_tables openvswitch nf_conntrack_ipv6 nf_nat_ipv6 nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_defrag_ipv6 nf_nat nf_conntrack binfmt_misc zfs(PO) zunicode(PO) zavl(PO) zcommon(PO) [ 1912.004575] znvpair(PO) spl(O) bridge 8021q garp mrp stp llc vmx_crypto kvm ib_iser rdma_cm iw_cm ib_cm ib_core configfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi autofs4 btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear ibmvscsi ibmveth crc32c_vpmsum virtio_blk [ 1912.004624] CPU: 12 PID: 31284 Comm: dpkg-deb Tainted: P O 4.10.0-40-generic #44~16.04.1-Ubuntu [ 1912.004626] task: c000000775551e00 task.stack: c0000007755ac000 [ 1912.004627] NIP: 00003fff86b71960 LR: 00003fff86b7319c CTR: 000000000000002d [ 1912.004628] REGS: c0000007755afea0 TRAP: 0901 Tainted: P O (4.10.0-40-generic) [ 1912.004629] MSR: 800000000280f033 <SF,VEC,VSX,EE,PR,FP,ME,IR,DR,RI,LE> [ 1912.004635] CR: 42004442 XER: 20000000 [ 1912.004636] CFAR: 00003fff86b719b4 SOFTE: 1 GPR00: 00000000000000a4 00003fffd53f7d70 00003fff86ba5008 0000000000000040 GPR04: 00000000038a20fc 00003fff86467d4b 00000000036c0ed8 000000000000002a GPR08: 00003fff81c41010 00000000000a20f5 0000000000800001 ffffffffffec0ed1 GPR12: 00000000000000a6 00003fff86c8db30 [ 1912.004646] NIP [00003fff86b71960] 0x3fff86b71960 [ 1912.004647] LR [00003fff86b7319c] 0x3fff86b7319c [ 1912.004647] Call Trace: To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-power-systems/+bug/1733864/+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
