Messages in this thread | | | Date | Thu, 19 Jul 2007 21:18:20 +0530 | From | Srivatsa Vaddagiri <> | Subject | Re: [PATCH] virtual sched_clock() for s390 |
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On Thu, Jul 19, 2007 at 08:29:06AM -0700, Jeremy Fitzhardinge wrote: > > - * Monotonic_clock - returns # of nanoseconds passed since time_init() > > + * Scheduler clock - returns current time in nanosec units. > > + * Now based on virtual cpu time to only account time the guest > > + * was actually running. > > > > Runn*ing*? Does it include time the VCPU spends idle/blocked? If not, > then the scheduler won't be able to tell how long a process has been > asleep.
Good point ..
I think we need a measure of both virtual and real time here - virtual for accounting task-execution time and real for accounting sleep (and perhaps rq-wait?) time.
> Maybe this doesn't matter (I had this problem in a version of > Xen's sched_clock, and I can't say I saw an ill effects from it).
I guess it will show up as some corner case behaviour, which people are yet to discover on virtual env.
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