From mboxrd@z Thu Jan  1 00:00:00 1970
From: Avi Kivity <avi@redhat.com>
Subject: Re: KVM usability
Date: Sun, 07 Mar 2010 13:35:57 +0200
Message-ID: <4B938F9D.7010207@redhat.com>
References: <20100226090147.GH15885@elte.hu> <4B879A2F.50203@redhat.com> <20100226103545.GA7463@elte.hu> <4B87A6BF.3090301@redhat.com> <20100226111734.GE7463@elte.hu> <4B8813F2.8090208@redhat.com> <20100227105643.GA17425@elte.hu> <d9c105ea1003011312s935c3c5haa1ec80aebe14d88@mail.gmail.com> <4B8C38B8.8010007@codemonkey.ws> <1267498953.2460.32.camel@x200> <20100302082118.GT1924@arachsys.com> <428008581.20100302103400@eternallybored.org>
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Cc: "Chris Webb on [KVM]" <kvm@vger.kernel.org>,
	Dustin Kirkland <kirkland@canonical.com>,
	Anthony Liguori <anthony@codemonkey.ws>,
	Ingo Molnar <mingo@elte.hu>,
	"Zhang, Yanmin" <yanmin_zhang@linux.intel.com>,
	Peter Zijlstra <peterz@infradead.org>, ming.m.lin@intel.com,
	sheng.yang@intel.com, Jes Sorensen <Jes.Sorensen@redhat.com>,
	Zachary Amsden <zamsden@redhat.com>,
	Gleb Natapov <gleb@redhat.com>,
	Arnaldo Carvalho de Melo <acme@redhat.com>,
	Fr??d??ric Weisbecker <fweisbec@gmail.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Arjan van de Ven <arjan@infradead.org>
To: =?UTF-8?B?SmVybmVqIFNpbW9uxI1pxI0=?=
	<jernej's-kvm@eternallybored.org>
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On 03/02/2010 11:34 AM, Jernej Simon=C4=8Di=C4=8D wrote:
> On Tuesday, March 2, 2010, 9:21:18, Chris Webb wrote:
>
>   =20
>> I remember about a year ago, someone asserting on the list that -usb=
device
>> tablet was very CPU intensive even when not in use, and should be av=
oided if
>> mouse support wasn't needed, e.g. on non-graphical VMs. Was that act=
ually a
>> significant hit, and is it still true today?
>>     =20
> It would appear that this is still the case, at least on slower hosts
> - on Atom Z530 (1,6GHz), the XP VM uses ~30% CPU when idle with
> -usbdevice tablet, but only ~4% without it. However, on a faster host
> (Core2 Quad 2,66GHz), there's practically no difference (Vista x64 VM
> uses ~1% CPU when idle regardless of -usbdevice tablet).
>   =20

Looks like the tablet is set to 100 Hz polling rate.  We may be able to=
=20
get away with 30 Hz or even less (ep_bInterval, in ms, in hw/usb-wacom.=
c).

--=20
error compiling committee.c: too many arguments to function