This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed- bionic' to 'verification-done-bionic'. If the problem still exists, change the tag 'verification-needed-bionic' to 'verification-failed- bionic'.
If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you! ** Tags added: verification-needed-bionic -- 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/1759723 Title: ISST-LTE:KVM:Ubuntu18.04:BostonLC:boslcp3:boslcp3g3:Guest conosle hangs after hotplug CPU add operation. Status in The Ubuntu-power-systems project: Fix Committed Status in linux package in Ubuntu: Fix Released Status in linux source package in Bionic: Fix Committed Bug description: Problem Description: =================== Performed HOTPLUG cpu attach operation for the guest and guest console becomes unresponsive. Steps to re-create: ================== 1. updated boslcp3 host BMC :116 & PNOR: 20180302 levels 2. Installed Ubuntu1804 on boslcp3 host & guests with trap issue fixes root@boslcp3:/home# uname -a Linux boslcp3 4.15.0-12-generic #13+leo20180320 SMP Tue Mar 20 13:10:42 CDT 2018 ppc64le ppc64le ppc64le GNU/Linux root@boslcp3:/home# uname -r 4.15.0-12-generic root@boslcp3g3:/kte/tools/setup.d# uname -a Linux boslcp3g3 4.15.0-12-generic #13+leo20180320 SMP Tue Mar 20 13:10:42 CDT 2018 ppc64le ppc64le ppc64le GNU/Linux root@boslcp3g3:/kte/tools/setup.d# uname -r 4.15.0-12-generic 3. Started HTX & stress-ng for on guest for 10-15 min 4. Cleaned up the tests to perform hot-plug and ensure enough memory and cpu was there (killed all Process using kill) 5. Performed cpu hot-plug and guest went into hung state Before Hotplug: root@boslcp3:~# virsh dumpxml boslcp3g3 | grep vcpu <vcpu placemen Hotplug add CPU: root@boslcp3:~# virsh setvcpus boslcp3g3 48 --live dumpxml: root@boslcp3:~# virsh dumpxml boslcp3g3 | grep cpu <vcpu placement='static' current='48'>64</vcpu> <vcpus> <vcpu id='0' enabled='yes' hotpluggable='no' order='1'/> <vcpu id='1' enabled='yes' hotpluggable='no' order='1'/> <vcpu id='2' enabled='yes' hotpluggable='no' order='1'/> <vcpu id='3' enabled='yes' hotpluggable='no' order='1'/> <vcpu id='4' enabled='yes' hotpluggable='no' order='2'/> <vcpu id='5' enabled='yes' hotpluggable='no' order='2'/> <vcpu id='6' enabled='yes' hotpluggable='no' order='2'/> <vcpu id='7' enabled='yes' hotpluggable='no' order='2'/> <vcpu id='8' enabled='yes' hotpluggable='no' order='3'/> <vcpu id='9' enabled='yes' hotpluggable='no' order='3'/> <vcpu id='10' enabled='yes' hotpluggable='no' order='3'/> <vcpu id='11' enabled='yes' hotpluggable='no' order='3'/> <vcpu id='12' enabled='yes' hotpluggable='no' order='4'/> <vcpu id='13' enabled='yes' hotpluggable='no' order='4'/> <vcpu id='14' enabled='yes' hotpluggable='no' order='4'/> <vcpu id='15' enabled='yes' hotpluggable='no' order='4'/> <vcpu id='16' enabled='yes' hotpluggable='no' order='5'/> <vcpu id='17' enabled='yes' hotpluggable='no' order='5'/> <vcpu id='18' enabled='yes' hotpluggable='no' order='5'/> <vcpu id='19' enabled='yes' hotpluggable='no' order='5'/> <vcpu id='20' enabled='yes' hotpluggable='no' order='6'/> <vcpu id='21' enabled='yes' hotpluggable='no' order='6'/> <vcpu id='22' enabled='yes' hotpluggable='no' order='6'/> <vcpu id='23' enabled='yes' hotpluggable='no' order='6'/> <vcpu id='24' enabled='yes' hotpluggable='no' order='7'/> <vcpu id='25' enabled='yes' hotpluggable='no' order='7'/> <vcpu id='26' enabled='yes' hotpluggable='no' order='7'/> <vcpu id='27' enabled='yes' hotpluggable='no' order='7'/> <vcpu id='28' enabled='yes' hotpluggable='no' order='8'/> <vcpu id='29' enabled='yes' hotpluggable='no' order='8'/> <vcpu id='30' enabled='yes' hotpluggable='no' order='8'/> <vcpu id='31' enabled='yes' hotpluggable='no' order='8'/> <vcpu id='32' enabled='yes' hotpluggable='yes' order='9'/> <vcpu id='33' enabled='yes' hotpluggable='yes' order='9'/> <vcpu id='34' enabled='yes' hotpluggable='yes' order='9'/> <vcpu id='35' enabled='yes' hotpluggable='yes' order='9'/> <vcpu id='36' enabled='yes' hotpluggable='yes' order='10'/> <vcpu id='37' enabled='yes' hotpluggable='yes' order='10'/> <vcpu id='38' enabled='yes' hotpluggable='yes' order='10'/> <vcpu id='39' enabled='yes' hotpluggable='yes' order='10'/> <vcpu id='40' enabled='yes' hotpluggable='yes' order='11'/> <vcpu id='41' enabled='yes' hotpluggable='yes' order='11'/> <vcpu id='42' enabled='yes' hotpluggable='yes' order='11'/> <vcpu id='43' enabled='yes' hotpluggable='yes' order='11'/> <vcpu id='44' enabled='yes' hotpluggable='yes' order='12'/> <vcpu id='45' enabled='yes' hotpluggable='yes' order='12'/> <vcpu id='46' enabled='yes' hotpluggable='yes' order='12'/> <vcpu id='47' enabled='yes' hotpluggable='yes' order='12'/> <vcpu id='48' enabled='no' hotpluggable='yes'/> <vcpu id='49' enabled='no' hotpluggable='yes'/> <vcpu id='50' enabled='no' hotpluggable='yes'/> <vcpu id='51' enabled='no' hotpluggable='yes'/> <vcpu id='52' enabled='no' hotpluggable='yes'/> <vcpu id='53' enabled='no' hotpluggable='yes'/> <vcpu id='54' enabled='no' hotpluggable='yes'/> <vcpu id='55' enabled='no' hotpluggable='yes'/> <vcpu id='56' enabled='no' hotpluggable='yes'/> <vcpu id='57' enabled='no' hotpluggable='yes'/> <vcpu id='58' enabled='no' hotpluggable='yes'/> <vcpu id='59' enabled='no' hotpluggable='yes'/> <vcpu id='60' enabled='no' hotpluggable='yes'/> <vcpu id='61' enabled='no' hotpluggable='yes'/> <vcpu id='62' enabled='no' hotpluggable='yes'/> <vcpu id='63' enabled='no' hotpluggable='yes'/> </vcpus> <cpu mode='host-model' check='partial'> </cpu> root@boslcp3:~# 6. After this operation, guest becomes unrepsonsive as below root@boslcp3g3:~# [ 3626.140773] INFO: task jbd2/vda2-8:584 blocked for more than 120 seconds. [ 3626.146375] Tainted: G W 4.15.0-12-generic #13+leo20180320 [ 3626.146457] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 3626.146624] INFO: task systemd-journal:665 blocked for more than 120 seconds. [ 3626.146699] Tainted: G W 4.15.0-12-generic #13+leo20180320 [ 3626.146768] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 3626.146939] INFO: task rs:main Q:Reg:1995 blocked for more than 120 seconds. [ 3626.147016] Tainted: G W 4.15.0-12-generic #13+leo20180320 [ 3626.147088] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 3626.147285] INFO: task kworker/u128:2:57691 blocked for more than 120 seconds. [ 3626.147361] Tainted: G W 4.15.0-12-generic #13+leo20180320 [ 3626.147434] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 3626.147622] INFO: task smbd:1449 blocked for more than 120 seconds. [ 3626.147686] Tainted: G W 4.15.0-12-generic #13+leo20180320 [ 3626.147760] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 3626.147875] INFO: task smbd:1452 blocked for more than 120 seconds. [ 3626.147937] Tainted: G W 4.15.0-12-generic #13+leo20180320 [ 3626.148010] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 3626.148110] INFO: task smbd:1454 blocked for more than 120 seconds. [ 3626.148173] Tainted: G W 4.15.0-12-generic #13+leo20180320 [ 3626.148245] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 3626.148344] INFO: task cron:1461 blocked for more than 120 seconds. [ 3626.148406] Tainted: G W 4.15.0-12-generic #13+leo20180320 [ 3626.148488] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. root@boslcp3g3:~# root@boslcp3g3:~# ps -ef | grep stress-ng [ 3746.978098] INFO: task jbd2/vda2-8:584 blocked for more than 120 seconds. [ 3746.978221] Tainted: G W 4.15.0-12-generic #13+leo20180320 [ 3746.978301] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 3746.978447] INFO: task systemd-journal:665 blocked for more than 120 seconds. [ 3746.978534] Tainted: G W 4.15.0-12-generic #13+leo20180320 [ 3746.978607] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 4446.361899] systemd[1]: Failed to start Journal Service. [ 4897.632142] systemd[1]: Failed to start Journal Service. ^Z ^X ^C ^Z ^X ^C 7. ping to boslcp3g3 is fine but guest console is not repsonding [ipjoga@kte (AUS) ~]$ ping boslcp3g3 PING boslcp3g3.isst.aus.stglabs.ibm.com (10.33.12.73) 56(84) bytes of data. 64 bytes from boslcp3g3.isst.aus.stglabs.ibm.com (10.33.12.73): icmp_seq=1 ttl=64 time=0.182 ms 64 bytes from boslcp3g3.isst.aus.stglabs.ibm.com (10.33.12.73): icmp_seq=2 ttl=64 time=0.196 ms ^C 8. Took dump for the guest, attache vmcore & other logs. Thanks to the Linux block community, I'm now aware of two commits that should fix this issue. https://github.com/torvalds/linux/commit/20e4d813931961fe26d26a1e98b3aba6ec00b130 blk-mq: simplify queue mapping & schedule with each possisble CPU The previous patch assigns interrupt vectors to all possible CPUs, so now hctx can be mapped to possible CPUs, this patch applies this fact to simplify queue mapping & schedule so that we don't need to handle CPU hotplug for dealing with physical CPU plug & unplug. With this simplication, we can work well on physical CPU plug & unplug, which is a normal use case for VM at least. Make sure we allocate blk_mq_ctx structures for all possible CPUs, and set hctx->numa_node for possible CPUs which are mapped to this hctx. And only choose the online CPUs for schedule. https://github.com/torvalds/linux/commit/84676c1f21e8ff54befe985f4f14dc1edc10046b genirq/affinity: assign vectors to all possible CPUs Currently we assign managed interrupt vectors to all present CPUs. This works fine for systems were we only online/offline CPUs. But in case of systems that support physical CPU hotplug (or the virtualized version of it) this means the additional CPUs covered for in the ACPI tables or on the command line are not catered for. To fix this we'd either need to introduce new hotplug CPU states just for this case, or we can start assining vectors to possible but not present CPUs. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-power-systems/+bug/1759723/+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
