Some good news: With bug 1534545 fixed I was now able to upgrade to the Xenial 4.4 kernel. On the 4x CPU instance two parallel adt-run loops have now run for about two hours without any dmesg spew. Stéphane has run "lxc-test-concurrent -j 16 -i 10" twice on the 8x CPU instance successfully too.
Bad news: I rebooted the 8x CPU instance (also xenial du jour with 4.4 kernel), and didn't do anything on it. After just sitting idle for an hour or two ssh stopped responding and nova console-log shows http://paste.ubuntu.com/14857144/ (only a hard reboot helped). So it wet its pants without actually doing any action. So it appears it's not fully fixed yet, but muuch better. I'll do some more smoke testing, and if 4x CPU instances work, this is good enough to put this into production. I'll keep the old Calxeda instances alive as a fallback for a while, of course. -- 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/1531768 Title: [arm64] multithreaded processes get locked up in futexes Status in linux package in Ubuntu: Confirmed Bug description: I created an 8 CPU arm64 instance on Canonical's Scalingstack (which I want to use for armhf autopkgtesting in LXD). I started with wily as that has lxd available (it's not yet available in trusty nor the PPA for arm64). However, pretty much any LXD task that I do (I haven't tried much else) on this machine takes unbearably long. A simple "lxc profile set default raw.lxc lxc.seccomp=" or "lxc list" takes several minutes. I see tons of [ 1020.971955] rcu_sched kthread starved for 6000 jiffies! g1095 c1094 f0x0 [ 1121.166926] INFO: task fsnotify_mark:69 blocked for more than 120 seconds. in dmesg (the attached apport info has the complete dmesg). ProblemType: Bug DistroRelease: Ubuntu 15.10 Package: linux-image-4.2.0-22-generic 4.2.0-22.27 ProcVersionSignature: User Name 4.2.0-22.27-generic 4.2.6 Uname: Linux 4.2.0-22-generic aarch64 AlsaDevices: total 0 crw-rw---- 1 root audio 116, 1 Jan 7 09:18 seq crw-rw---- 1 root audio 116, 33 Jan 7 09:18 timer AplayDevices: Error: [Errno 2] No such file or directory: 'aplay' ApportVersion: 2.19.1-0ubuntu5 Architecture: arm64 ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord' AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: CRDA: N/A Date: Thu Jan 7 09:24:01 2016 IwConfig: eth0 no wireless extensions. lo no wireless extensions. lxcbr0 no wireless extensions. Lspci: 00:00.0 Host bridge [0600]: Red Hat, Inc. Device [1b36:0008] Subsystem: Red Hat, Inc Device [1af4:1100] Control: I/O- Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize libusb: -99 PciMultimedia: ProcEnviron: TERM=screen PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash ProcFB: ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-22-generic root=LABEL=cloudimg-rootfs earlyprintk RelatedPackageVersions: linux-restricted-modules-4.2.0-22-generic N/A linux-backports-modules-4.2.0-22-generic N/A linux-firmware 1.149.3 RfKill: Error: [Errno 2] No such file or directory: 'rfkill' SourcePackage: linux UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev' UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1531768/+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
