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Subject: Re: [PATCH 5/6] tools lib traceevent: Add page_size field to pevent
From: Namhyung Kim <namhyung@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Ingo Molnar <mingo@kernel.org>, Namhyung Kim <namhyung.kim@lge.com>,
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Date: Sat, 13 Apr 2013 11:08:08 +0900
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2013-04-12 (금), 21:26 -0400, Steven Rostedt:
> On Sat, 2013-04-13 at 10:17 +0900, Namhyung Kim wrote:
> 
> > > 
> > > I just want to know more about this patch before I ack it.
> > 
> > The page size of traced system can be different than current system's
> > because the recorded data file might be analyzed in a different machine.
> > In this case we should use original page size of traced system when
> > accessing the data file, so this information needs to be saved.
> 
> I understand that, it's just strange that it's not used anywhere in the
> library, or the patch series (that I can find).
> 
> It would make more sense if another patch used this new interface. I'm
> sure new code will, but the patch should be part of a patch series that
> needs it.

I know you knew that already. :)

I think it only affects trace-cmd as it's the only user that accesses
raw ring-buffer contents for now.  I found it during writing code also
accesses the ring buffer (with kbuffer code) - perf ftrace. :)

But the code is in a very early stage and needs to handle so many things
before posting to the list.  So I just wanted to post a part of the
preparation first.

Thanks,
Namhyung