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 09:14:10 +0100
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Cc: Anthony Liguori <aliguori@linux.vnet.ibm.com>,
	Avi Kivity <avi@redhat.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: "Frank Ch. Eigler" <fche@redhat.com>
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* Frank Ch. Eigler <fche@redhat.com> wrote:

> Hi -
> 
> On Tue, Mar 16, 2010 at 06:04:10PM -0500, Anthony Liguori wrote:
> > [...]
> > The only way to really address this is to change the interaction.  
> > Instead of running perf externally to qemu, we should support a perf 
> > command in the qemu monitor that can then tie directly to the perf 
> > tooling.  That gives us the best possible user experience.
> 
> To what extent could this be solved with less crossing of 
> isolation/abstraction layers, if the perfctr facilities were properly 
> virtualized? [...]

Note, 'perfctr' is a different out-of-tree Linux kernel project run by someone 
else: it offers the /dev/perfctr special-purpose device that allows raw, 
unabstracted, low-level access to the PMU.

I suspect the one you wanted to mention here is called 'perf' or 'perf 
events'. (and used to be called 'performance counters' or 'perfcounters' until 
it got renamed about a year ago)

Thanks,

	Ingo