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- artful' to 'verification-done-artful'. If the problem still exists, change the tag 'verification-needed-artful' to 'verification-failed- artful'.
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-artful -- 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/1755979 Title: Cpu utilization showing system time for kvm guests (performance) (sysstat) Status in The Ubuntu-power-systems project: Fix Committed Status in linux package in Ubuntu: Fix Committed Status in linux source package in Artful: Fix Committed Status in linux source package in Bionic: Fix Committed Bug description: == SRU Justification == All KVM guest cpu utilization is being reported as sys% time in the host. It turns out Guest time accounting (CONFIG_VIRT_CPU_ACCOUNTING_GEN) has been broken since v4.13 by commit 8b24e69fc47e436. Commit 61bd0f66ff92 fixes this bug and is included in mainline as of v4.16-rc5. The commit was cc'd to upstream stable, but has not yet landed in upstream 4.15. == Fix == 61bd0f66ff92 ("KVM: PPC: Book3S HV: Fix guest time accounting with VIRT_CPU_ACCOUNTING_GEN") == Regression Potential == Low. Also cc'd to stable, so it has had additionl upstream review. Limited to powerpc. == Test Case == A test kernel was built with this patch and tested by the original bug reporter. The bug reporter states the test kernel resolved the bug. == Comment: #0 - JENIFER HOPPER <jhop...@us.ibm.com> - 2018-03-14 16:20:47 == +++ This bug was initially created as a clone of Bug #163375 +++ ---Problem Description--- All KVM guest cpu utilization is being reported as sys% time in the host. It turns out Guest time accounting (CONFIG_VIRT_CPU_ACCOUNTING_GEN) has been broken since v4.13 by commit: commit 8b24e69fc47e43679bb29ddb481aa0e8dce2a3c5 Author: Paul Mackerras <pau...@ozlabs.org> Date: Mon Jun 26 15:45:51 2017 +1000 KVM: PPC: Book3S HV: Close race with testing for signals on guest entry --- That is now fixed and upstream accepted in Paulus' tree as git commit: https://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc.git/commit/?h=kvm-ppc-fixes&id=61bd0f66ff92d5ce765ff9850fd3cbfec773c560 ("KVM: PPC: Book3S HV: Fix guest time accounting with VIRT_CPU_ACCOUNTING_GEN") Please include this patch in Ubuntu so that guest cpu accounting is correct. Contact Information = jhop...@us.ibm.com ---uname output--- Linux ltc-b114 4.15.0-10-generic #11-Ubuntu SMP Tue Feb 13 18:21:52 UTC 2018 ppc64le ppc64le ppc64le GNU/Linux Machine Type = 5104-22C ---Debugger--- A debugger is not configured ---Steps to Reproduce--- Start a KVM guest, run something that generates cpu utilization in the guest, observe mpstat on the host. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-power-systems/+bug/1755979/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : firstname.lastname@example.org Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp