Control: severity -1 important Control: tag -1 moreinfo On Wed, 2017-08-09 at 22:46 +0200, Michael Lass wrote: > Package: src:linux > Version: 4.9.30-2+deb9u3 > Severity: normal > Tags: patch > > Dear Maintainer, > > running Debian Stretch as a paravirtualized guest under Xen, the kernel > obtains its cpu steal time counter from the virtualization host. On some > hosts, occasionally a slight decrease in the cpu steal time is returned > which leads to an overflow of unsigned variables in the kernel and > subsequent errors in steal time accounting (such as backwards running > counters). This renders tools like "top" or "vmstat" broken in a way > that the cpu utilization cannot be determined anymore. > > While this is likely a bug in the virtualization environment, the kernel > running as a guest should deal with this gracefully. I attached a patch > to this report which fixes the errors caused by this on the guest. > Kernel versions 4.7 and older, as well as 4.11 and newer should not be > affected by this issue. [...]
I agree that the kernel ought to work around this, but I'm hesitant to add a fix that doesn't look like any upstream change. Why and how do you think this was fixed in 4.11? Ben. -- Ben Hutchings If the facts do not conform to your theory, they must be disposed of.
signature.asc
Description: This is a digitally signed message part
