[ltt-dev] Need for zipped traces ?

Mathieu Desnoyers compudj at krystal.dyndns.org
Tue Aug 4 09:41:26 EDT 2009

* Ajit R (ajitrzid at yahoo.com) wrote:
> Hi
>   Just wondering if zipping traces as they are being generated makes sense. This would be useful on embedded targets which could quickly run out of resources.

It could, but it requires extra CPU time while tracing.

I would rather use something based on gzip (zlib1). Using the most
lightweight compression levels should be able to compress one subbuffer
after another without wasting too much resources.

However, with the recent LTTng versions, given we use zero-copy splice
to write to disk, the "easy way" to do it (maybe not the best) is to
write data to a temporary file (which will stay in the buffer cache),
compress it and append it to the tracefile, and clear the temporary

All this can be done by modifying lttd.


> Thanks
> Ajit
> _______________________________________________
> ltt-dev mailing list
> ltt-dev at lists.casi.polymtl.ca
> http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev

Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68

More information about the lttng-dev mailing list