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From: Marcelo Tosatti <mtosatti@redhat.com>
To: Avi Kivity <avi@qumranet.com>
Cc: Sheng Yang <sheng.yang@intel.com>, kvm <kvm@vger.kernel.org>
Subject: Re: [patch 3/3] KVM: PIT: fix injection logic and count
Date: Tue, 29 Jul 2008 11:42:57 -0300	[thread overview]
Message-ID: <20080729144257.GC26984@dmt.cnet> (raw)
In-Reply-To: <488F133E.7010702@qumranet.com>

On Tue, Jul 29, 2008 at 03:55:26PM +0300, Avi Kivity wrote:
> Sometimes the guest leaves the timer enabled but the output pin masked,  
> (e.g. it doesn't use the timer bug doesn't bother to turn it off  
> properly).  This results in extraneous interrupts, causing unnecessary  
> vmexits and increased power usage.
>
> But if we detect that the guest isn't processing the interrupts, we can  
> turn the timer off, and after the next injection, calculate the number  
> of missing interrupts, and turn the timer on again.  This will have to  
> be done carefully (taking care of the guest adjusting the frequency  
> during the period where we missed injections, for example).

Sounds like a good idea, I'll try something later.

>
> Comments?  Questions?  Patches?


  reply	other threads:[~2008-07-29 14:43 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-07-26 20:00 [patch 0/3] fix PIT injection Marcelo Tosatti
2008-07-26 20:00 ` [patch 1/3] KVM: Add irq ack notifier list Marcelo Tosatti
2008-07-26 20:01 ` [patch 2/3] KVM: irq ack notification Marcelo Tosatti
2008-07-26 20:01 ` [patch 3/3] KVM: PIT: fix injection logic and count Marcelo Tosatti
2008-07-28  5:56   ` Yang, Sheng
2008-07-29 14:29     ` Marcelo Tosatti
2008-07-29 12:55   ` Avi Kivity
2008-07-29 14:42     ` Marcelo Tosatti [this message]
2008-08-12 15:35   ` David S. Ahern
2008-07-28  4:31 ` [patch 0/3] fix PIT injection David S. Ahern
2008-07-29 12:50 ` Avi Kivity
2008-07-29 21:50 ` Dor Laor
2008-07-30 14:15   ` Marcelo Tosatti
2008-07-30 14:56     ` Sheng Yang
2008-07-30 21:48     ` Dor Laor

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