Public bug reported: -- Problem Description -- The following upstream patches are needed for Ubuntu to fix a hang situation reported when executing ppc64_cpu --smt=on that occurs with various disk types. We need whichever ones have not yet been pulled into the base.
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=e57690fe009b2ab0cee8a57f53be634540e49c9d https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=0e87e58bf60edb6bb28e493c7a143f41b091a5e5 https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=135e8c9250dd5c8c9aae5984fde6f230d0cbfeaf https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=c02ebfdddbafa9a6a0f52fbd715e6bfa229af9d3 https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d1b1cea1e58477dad88ff769f54c0d2dfa56d923 https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=36e1f3d107867b25c616c2fd294f5a1c9d4e5d09 https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=71f79fb3179e69b0c1448a2101a866d871c66e7f The hang problem can be reproduced with the following shell script using an NVMe device executed on kernel versions 4.4.0-45 and 4.4.0-59 within 30 minutes. It was also reproduced on a 4.8.0-32-generic kernel, although it took over 3 hours to manifest. #!/bin/bash if [[ ${#} -eq 0 ]]; then ${0} breaker & while true; do dd if=/dev/nvme0n1 bs=1024k of=/dev/null done elif [[ ${1} == "breaker" ]]; then while true; do ppc64_cpu --smt=off sleep 5 ppc64_cpu --smt=on sleep 5 done fi ** Affects: linux (Ubuntu) Importance: Undecided Assignee: Taco Screen team (taco-screen-team) Status: New ** Tags: architecture-ppc64le bugnameltc-146759 severity-critical targetmilestone-inin16041 ** Tags added: architecture-ppc64le bugnameltc-146759 severity-critical targetmilestone-inin16041 ** Changed in: ubuntu Assignee: (unassigned) => Taco Screen team (taco-screen-team) ** Package changed: ubuntu => linux (Ubuntu) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1662666 Title: ISST-LTE:pNV: ppc64_cpu command is hung w HDs, SSDs and NVMe To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1662666/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
