Re: Re: Re: [RFC PATCH 0/6] virtio-trace: Support virtio-trace

From: Yoshihiro YUNOMAE
Date: Wed Jul 25 2012 - 05:13:11 EST


Hi Stefan,

(2012/07/24 22:41), Stefan Hajnoczi wrote:
On Tue, Jul 24, 2012 at 12:19 PM, Yoshihiro YUNOMAE
<yoshihiro.yunomae.ez@xxxxxxxxxxx> wrote:
Are you using text formatted ftrace?
No, currently using raw format, butãwe'd like to reformat it in text.

Capturing the info necessary to translate numbers into symbols is one
of the problems of host<->guest tracing so I'm curious how you handle
this :).

Right, your consideration is true.

Apologies for my lack of ftrace knowledge but how useful is the raw
tracing data on the host? How do you pretty-print it in
human-readable form?

perf and trace-cmd can actually translate raw-formatted trace data to
text-formatted trace data by using information of kernel or trace
format under tracing/events directory in debugfs. In the same way, if
the information of a guest is exported to a host, we can translate
raw trace data of a guest to text trace data on a host. We will use
9pfs to export that.

Thank you,

--
Yoshihiro YUNOMAE
Software Platform Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: yoshihiro.yunomae.ez@xxxxxxxxxxx


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