Hi Alex, That sounds rather odd. The only event that should happen when there are no request going through the memory system (the KVM CPU operates directly on the underlying backing store), is the refresh, which happens roughly every 64 ms. Could you elaborate on what event it is you are referring to?
I’ll try and have a look as well to see what’s happening. Thanks, Andreas On 6/12/14, 8:59 PM, "Alexandru Duţu via gem5-dev" <[email protected]> wrote: >Hi everyone, > >It seems that the KVM enter-exit cycles with 0 instructions executed are >caused by the events scheduled from the DRAMCtrl object. The issues is >that >these events have a very short period which is not sufficient for KvmCPU >to >even start execution. > >I am not familiar with DRAMCtrl memory, it seems that SimpleMemory does >not >have this issue with KvmCPU. > >Best regards, > > >On Wed, Jun 11, 2014 at 5:05 PM, Alexandru Duţu <[email protected]> >wrote: > >> Hi all, >> >> I am trying to understand the current behaviour of KvmCPU. Previous to >>the >> following changeset >> >> http://repo.gem5.org/gem5/rev/2360411a16be >> >> after every kvmRun the status was switched to runningService, a new >>event >> was scheduled to the event queue and so with new tick handleKvmExit >>will be >> called. >> >> However, with the latest changesets on kvm ( >> http://repo.gem5.org/gem5/rev/5c2ecad1a3c9) there are a lot of KVM >> enter-exit cycles with 0 instructions executed. It seems that the vCPU >>gets >> interrupted by the timer a lot more, which causes kvm to exit without >> executing anything. >> >> An explanation for this behaviour is highly appreciated, is there a need >> for timer interrupts that are not allowing the vCPU to actually >>execute? Or >> this might be a side effect of the differences in timers across >>different >> x86 vendors (I am running on an AMD system)? >> >> Best regards, >> -- >> Alex >> > > > >-- >Alex >_______________________________________________ >gem5-dev mailing list >[email protected] >http://m5sim.org/mailman/listinfo/gem5-dev -- IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you. ARM Limited, Registered office 110 Fulbourn Road, Cambridge CB1 9NJ, Registered in England & Wales, Company No: 2557590 ARM Holdings plc, Registered office 110 Fulbourn Road, Cambridge CB1 9NJ, Registered in England & Wales, Company No: 2548782 _______________________________________________ gem5-dev mailing list [email protected] http://m5sim.org/mailman/listinfo/gem5-dev
