On August 11, 2011, Avi Kivity wrote: > On 08/09/2011 06:33 PM, Nick wrote: > > Hi, > > > > Just joined this list, looking for leads to solve a similar-sounding > > problem (guest processes hanging for seconds or minutes when host IO > > load is high). I'll say more in a separate email, but I caught the end > > of this thread and wanted to ask about kvm-clock. > > > > Naively I'd have thought that using the wrong clock would not actually > > *cause* hangs like this. Or is that what you're implying? > > Using the wrong clock easily causes hangs. The system schedules a > wakeup in 3 ms, wrong clock causes it to wakeup in 3 years, you get a > hang for (3 years - 3 ms). I am wondering though why the system time would be used to schedule wakeups when something a little more like the posix CLOCK_MONOTONIC would make more sense. You (at least I don't think you do) really don't want host clock changes to interfere with a guest so much that it sleeps forever. -- Thomas Fjellstrom thomas@xxxxxxxxxxxxx -- 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
