[ltt-dev] performance results I measured with the latest lttng patches

Mathieu Desnoyers compudj at krystal.dyndns.org
Thu Sep 25 15:50:57 EDT 2008

* Jiaying Zhang (jiayingz at google.com) wrote:
> Hi Jan,
> >
> > > lttng-compiled-in, all markers disabled: Throughput 743.931 MB/sec
> > > lttng-compiled-in, default markers enabled, taking an active trace in
> > normal
> > > mode: Throughput 500.24 MB/sec
> >
> > Isn't lttng-compile-out missing here? Or did you ran the same base kernel?
> I used the same base kernel here.
> Jiaying

To to give an idea of the order of magniture of kernel effect on tbench
on my dual 4-cores box Intel box :

stock kernel 2.6.27-rc6 : 2024MB/s
stock kernel 2.6.27-rc7 : 1989MB/s

1.7% slowdown, with exactly the same config. And this is between
rc releases where the diff consists mostly of _bugfixes_.

I start to doubt tbench represents well "real" workloads, given it's
mostly doing kernel interaction and almost nothing in userspace.


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

More information about the lttng-dev mailing list