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

[Yoshihiro YUNOMAE]

Hi Stefan,

(2012/07/24 22:41), Stefan Hajnoczi wrote:
> On Tue, Jul 24, 2012 at 12:19 PM, Yoshihiro YUNOMAE
> <address@hidden> wrote:
> > > > Are you using text formatted ftrace?
> > No, currently using raw format, but　we'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: address@hidden