Re: Login time

[Federico Mena Quintero <federico ximian com>]

El mar, 10-04-2007 a las 10:54 -0400, Michael R. Head escribi�> Doesn't strace drastically affect performance? I thought the goal was to
> see how long these parts of the login process take under normal
> conditions.

#include <uncertainty-principle.h>

The overhead from strace doesn't seem to be terrible... it's certainly
better than not being able to get any timings at all :)  I haven't timed
it with a stopwatch, though.

I'd *love* to use a less pedestrian tool.  Does anyone know if Systemtap
is mature enough for this?  We'd need to say, "tell me every time
<function> gets called in this process", for a bunch of processes.

[Can anyone with Solaris and Dtrace help us out?]

In the end, what we need is a one-step, reproducible way to get login
timings.  Otherwise, whatever optimizations we do right now will go to
hell when people start piling more code on top of everything.  We need
to be able to run these tests regularly and without a lot of manual
work.

  Federico