> On 2012-09-12 15:54, Anthony Liguori wrote: >> >> Hi, >> >> We've been running into a lot of problems lately with Windows guests and >> I think they all ultimately could be addressed by revisiting the missed >> tick catchup algorithms that we use. Mike and I spent a while talking >> about it yesterday and I wanted to take the discussion to the list to >> get some additional input. >> >> Here are the problems we're seeing: >> >> 1) Rapid reinjection can lead to time moving faster for short bursts of >> time. We've seen a number of RTC watchdog BSoDs and it's possible >> that at least one cause is reinjection speed. >> >> 2) When hibernating a host system, the guest gets is essentially paused >> for a long period of time. This results in a very large tick catchup >> while also resulting in a large skew in guest time. >> >> I've gotten reports of the tick catchup consuming a lot of CPU time >> from rapid delivery of interrupts (although I haven't reproduced this >> yet).
Guys, not much that I can contribute to solving the problem, but I have a bunch of VMs where this happens _every_ time I resume a snapshot (but without hibernating). In case this could be a connected problem and you need help testing a patch, I'm more than happy to help. -Clemens
