https://bugzilla.kernel.org/show_bug.cgi?id=191481 Bug ID: 191481 Summary: Virtual machine CPU counters are broken forever after live migration to system with "steal time overflow" KVM bug Product: Virtualization Version: unspecified Kernel Version: Found since 3.18.31, still resides in latest ubuntu 3.19..4.8 builds Hardware: Intel OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: kvm Assignee: virtualization_kvm@xxxxxxxxxxxxxxxxxxxx Reporter: ds@xxxxxxxx Regression: No All (at least, compiled for ubuntu) kernels had the stolen time overflow bug, described in links below: http://lists.gnu.org/archive/html/qemu-devel/2015-06/msg01295.html https://bugs.launchpad.net/linux/+bug/1494350 It was fixed (in ubuntu) on summer 2016, so till now still exists affected hosts. Kernels built before Apr 2016 bypass "%still" counter as is, so sar output likes this: 11:11:15 AM CPU %user %nice %system %iowait %steal %idle 11:10:48 AM all 0.00 0.00 0.50 0.00 0.00 99.50 11:10:49 AM all 0.00 0.00 0.00 0.00 18823208238479134720.00 203.06 11:10:50 AM all 0.00 0.00 0.00 0.00 0.00 100.00 While all newer kernel counters I've been tested sticks: 11:11:15 AM CPU %user %nice %system %iowait %steal %idle 07:07:56 AM all 0.50 0.00 0.00 0.00 0.00 99.50 07:07:57 AM all 0.00 0.00 0.50 0.00 0.00 99.50 07:07:58 AM all 0.00 0.00 0.50 0.00 0.00 99.50 07:07:59 AM all 0.00 0.00 0.00 0.00 100.00 0.00 07:08:00 AM all 0.00 0.00 0.00 0.00 100.00 0.00 07:08:01 AM all 0.00 0.00 0.00 0.00 100.00 0.00 %steal is always 100% after migration. I slightly suspect that the reason resides in commit 0185604c2d82c560dab2f2933a18f797e74ab5a8. -- You are receiving this mail because: You are watching the assignee of the bug. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
