From mboxrd@z Thu Jan  1 00:00:00 1970
From: Peter Zijlstra <peterz@infradead.org>
Subject: Re: [patch 4/4] KVM-trace port to tracepoints
Date: Wed, 23 Jul 2008 09:49:06 +0200
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Cc: Jan Kiszka <jan.kiszka@siemens.com>,
	Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>,
	akpm@linux-foundation.org, Ingo Molnar <mingo@elte.hu>,
	linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	"Feng(Eric) Liu" <eric.e.liu@intel.com>
To: Avi Kivity <avi@qumranet.com>
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On Tue, 2008-07-22 at 21:46 +0300, Avi Kivity wrote:
> Jan Kiszka wrote:
> > That's true - as long as you don't have to add/remove/modify
> > tracepoints. I had to do this job in the past (not for KVM). Having 1
> > spot in 1 file (based on generic probes) would be handier in that case
> > than 5 spots in 3 files. But if the KVM tracepoints are considered
> > stable in their number and structure, that shouldn't be an issue here.
> >
> >   
> 
> Tracepoints aren't stable; they are artefacts of the implementation.

Which IMHO makes it unsuitable for trace_mark() as that will be exported
to user-space, and every time you change your tracepoints you'll change
user visible things - not nice.