Re: [Qemu-devel] [PATCH v3 0/7] RTC: New logic to emulate RTC

[Zhang, Yang Z]

> -----Original Message-----
> From: Paolo Bonzini [mailto:address@hidden
> Sent: Wednesday, March 14, 2012 4:54 PM
> To: Zhang, Yang Z
> Cc: address@hidden; Jan Kiszka; address@hidden;
> address@hidden; Marcelo Tosatti
> Subject: Re: [PATCH v3 0/7] RTC: New logic to emulate RTC
> 
> Il 14/03/2012 09:52, Zhang, Yang Z ha scritto:
> >>>>> Is there any comments with the version 3?
> >>>
> >>> Can you explain why you dropped the logic to set the timer to the
> >>> next event?
> > Do you mean why I change the rtc logic? The reason is that: When a
> > guest is idle, the main activity inside qemu is the rtc update
> > timer(2 per second). In our experience(running 64 rhel6u1 guests), it
> > will decrease pkg C6 residency about 6%(6% means 2 watts in my box).
> > And normally, the guest will not use the update-end interrupt and
> > alarm. So there has no need to run a periodic timer when guest isn't
> > using it.
> 
> No, why you're keeping roughly the same logic as current QEMU, instead
> of the more radical changes that were in v2.
You are right. Actually, the v4 is ready and it uses the same logic with v2. 
Since I have other high priority task in hand, I don't test v4 too much. So i 
plan to delay it for a while and hope v3 can be accepted before v4 is ready.
If you really doesn't like the v3, I will pay more effort in v4 and will send 
out it ASAP. :)

best regards
yang