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From: Rik van Riel <riel@redhat.com>
To: Avi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>,
	kvm-devel <kvm-devel@lists.sourceforge.net>,
	linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: kvm & dyntick
Date: Fri, 12 Jan 2007 00:34:34 -0500	[thread overview]
Message-ID: <45A71DEA.9020307@redhat.com> (raw)
In-Reply-To: <45A66106.5030608@qumranet.com>

Avi Kivity wrote:

> dyntick-enabled guest:
> - reduce the load on the host when the guest is idling
>   (currently an idle guest consumes a few percent cpu)

You do not need dynticks for this actually.  Simple no-tick-on-idle
like Xen has works well enough.

While you're modifying the timer code, you might also want to add
proper accounting for steal time.  Time during which your guest
had a runnable process, but was not actually running itself, should
not be accounted against the currently running process.

I wonder if it would be possible to simply copy some of the timer
code from Xen.  They have the timing quirks worked out very well
and their timer_interrupt() is pretty nice code.

(Now I need to buy myself another VT box so I can help out with KVM :))

http://virt.kernelnewbies.org/ParavirtBenefits has some other features
you may want to have :)))

-- 
Politics is the struggle between those who want to make their country
the best in the world, and those who believe it already is.  Each group
calls the other unpatriotic.

  reply	other threads:[~2007-01-12  5:34 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-01-11 16:08 Avi Kivity
2007-01-12  5:34 ` Rik van Riel [this message]
2007-01-12  6:20 ` Ingo Molnar
2007-01-12 10:19   ` Ingo Molnar
2007-01-12 17:04     ` Avi Kivity
2007-01-14  8:39       ` Ingo Molnar
2007-01-12 23:25     ` [kvm-devel] " Dor Laor
2007-01-12 23:39       ` Thomas Gleixner
2007-01-14  8:51       ` Ingo Molnar

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