Cpu utilization showing system time for kvm guests (performance) (sysstat)
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
The Ubuntu-power-systems project |
Fix Released
|
High
|
Canonical Kernel Team | ||
linux (Ubuntu) |
Fix Released
|
High
|
Joseph Salisbury | ||
Artful |
Fix Released
|
High
|
Joseph Salisbury | ||
Bionic |
Fix Released
|
High
|
Joseph Salisbury |
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_
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_
== 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 <email address hidden> - 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_
commit 8b24e69fc47e436
Author: Paul Mackerras <email address hidden>
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:/
("KVM: PPC: Book3S HV: Fix guest time accounting with VIRT_CPU_
Please include this patch in Ubuntu so that guest cpu accounting is correct.
Contact Information = <email address hidden>
---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.
tags: | added: architecture-ppc64le bugnameltc-165731 severity-high targetmilestone-inin--- |
Changed in ubuntu: | |
assignee: | nobody → Ubuntu on IBM Power Systems Bug Triage (ubuntu-power-triage) |
affects: | ubuntu → kernel-package (Ubuntu) |
Changed in ubuntu-power-systems: | |
importance: | Undecided → High |
affects: | kernel-package (Ubuntu) → linux (Ubuntu) |
Changed in ubuntu-power-systems: | |
assignee: | nobody → Canonical Kernel Team (canonical-kernel-team) |
status: | New → Triaged |
tags: | added: triage-g |
Changed in linux (Ubuntu): | |
status: | New → Triaged |
importance: | Undecided → High |
Changed in linux (Ubuntu Artful): | |
status: | New → In Progress |
Changed in linux (Ubuntu Bionic): | |
status: | Triaged → In Progress |
Changed in linux (Ubuntu Artful): | |
importance: | Undecided → High |
assignee: | nobody → Joseph Salisbury (jsalisbury) |
Changed in linux (Ubuntu Bionic): | |
assignee: | Ubuntu on IBM Power Systems Bug Triage (ubuntu-power-triage) → Joseph Salisbury (jsalisbury) |
Changed in ubuntu-power-systems: | |
status: | Triaged → In Progress |
Changed in linux (Ubuntu Bionic): | |
status: | In Progress → Fix Committed |
Changed in linux (Ubuntu Artful): | |
status: | In Progress → Fix Committed |
Changed in ubuntu-power-systems: | |
status: | In Progress → Fix Committed |
Changed in ubuntu-power-systems: | |
status: | Fix Committed → Fix Released |
tags: |
added: targetmilestone-inin1804 removed: targetmilestone-inin--- |
tags: | added: cscc |
I built a test kernel with commit 61bd0f66ff92. The test kernel can be downloaded from: kernel. ubuntu. com/~jsalisbury /lp1755979
http://
Can you test this kernel and see if it resolves this bug?
Note, to test this kernel, you need to install both the linux-image and linux-image-extra .deb packages.
Thanks in advance!