[ltt-dev] lttv usage

[Alexandre Montplaisir]

Hi Kalyana,

On 11-10-03 01:46 PM, Kalyana Sundaram wrote:
> Hi,
>
> I would like to essentially view my existing trace files in CSV format using the lttv. I am currently using Ubuntu 10.04 (Lucid). 
> It doesn't seem to recognize the file in any context. Is there a workaround this.
>
> ii) Is there a way to make modifications so that I query specific data like overwrites alone for the Disk I/O using lttv.

The current version of LTTV is tightly coupled with the
"liblttvtraceread" trace reading library, and thus can only read traces
in this format. Only the older LTTng 0.x and UST 0.x output traces in
this format.

There is a new player in town: Babeltrace, which is both a trace reader
and converter. It allows creating custom plugins for different trace
formats, so that one can convert to and from any other supported format.
The mid-to-long-term plan is to port LTTV to the Babeltrace libraries,
which would allow opening in LTTV traces in any format supported by
Babeltrace.

>
> iii) I would like to know if the lttv will be able to query across large trace files of the order of several GB at least.

Definitely, I have personally tested it with traces up to 10 GB in size.
There is also ongoing work to store state data on disk instead of in RAM
(which I'm incidentally working on), which would allow opening and
analyzing traces of theoretically any size.


Cheers,

-- 
Alexandre Montplaisir
DORSAL lab,
École Polytechnique de Montréal