On 07/30/2009 08:02 PM, Roman Steiner wrote:
hej hej,
i've a question about the virtual time implementation in kvm/qemu.
with the monitor commands stop / continue you can stop and start the
guest system, but the system clock is still running.
i\ve done the following experiment:
* start the guest system
* display the system time by running 'date' in the guest system
* stop via the monitor
* way for a minute or so
* continue via the monitor
* display the system time with 'date' in the guest system
result: the system clock of the guest system was running the whole time
for what i need it:
i'm working on a simulation of a wireless network with at least 100
nodes (routers). each node should be represented by a kvm instance
with a minimal os and some daemons (mainyl routing deamons). because
the system gets overloaded some processes (kvm instances) are starving
and the simulation is not working any more. so i would like to stop
and start the guest system by the simulation program to keep them in
order. therefore stopping and starting must be fast and it must be a
full stop.
Essentially, the scheduler is also stopping and starting the guests. So
I think that instead of writing another scheduler to pause and unpause
guests, you can adjust qemu to run time in slow motion. That should
reduce the interrupt rate and therefore the system load.
Not sure where exactly this needs to change, probably where qemu reads
the host time and sets host timers.
--
error compiling committee.c: too many arguments to function
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