From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ingo Molnar <mingo@elte.hu>
Subject: Re: [PATCH] Enhance perf to collect KVM guest os statistics from
 host side
Date: Wed, 17 Mar 2010 09:59:00 +0100
Message-ID: <20100317085900.GG16374@elte.hu>
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Cc: "Frank Ch. Eigler" <fche@redhat.com>,
	Anthony Liguori <aliguori@linux.vnet.ibm.com>,
	"Zhang, Yanmin" <yanmin_zhang@linux.intel.com>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Sheng Yang <sheng@linux.intel.com>,
	linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	Marcelo Tosatti <mtosatti@redhat.com>,
	oerg Roedel <joro@8bytes.org>,
	Jes Sorensen <Jes.Sorensen@redhat.com>,
	Gleb Natapov <gleb@redhat.com>,
	Zachary Amsden <zamsden@redhat.com>, ziteng.huang@intel.com
To: Avi Kivity <avi@redhat.com>
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* Avi Kivity <avi@redhat.com> wrote:

> On 03/17/2010 10:16 AM, Ingo Molnar wrote:
> >* Avi Kivity<avi@redhat.com>  wrote:
> >
> >> Monitoring guests from the host is useful for kvm developers, but less so
> >> for users.
> >
> > Guest space profiling is easy, and 'perf kvm' is not about that. (plain 
> > 'perf' will work if a proper paravirt channel is opened to the host)
> >
> > I think you might have misunderstood the purpose and role of the 'perf 
> > kvm' patch here? 'perf kvm' is aimed at KVM developers: it is them who 
> > improve KVM code, not guest kernel users.
> 
> Of course I understood it.  My point was that 'perf kvm' serves a tiny 
> minority of users. [...]

I hope you wont be disappointed to learn that 100% of Linux, all 13+ million 
lines of it, was and is being developed by a tiny, tiny, tiny minority of 
users ;-)

> [...]  That doesn't mean it isn't useful, just that it doesn't satisfy all 
> needs by itself.

Of course - and it doesnt bring world peace either. One step at a time.

Thanks,

	Ingo