[hobbit] fping tuning

[Henrik Stoerner]

On Thu, Apr 27, 2006 at 07:39:53AM +0200, Henrik Stoerner wrote:
> On Wed, Apr 26, 2006 at 05:49:45PM -0400, Schwimmer, Eric E *HS wrote:
> > So this leads me to believe that it is a problem solely with fping;  if
> > they had a public forum or a mailing list, I'd be whining there instead
> > of here. :)  I can't say that I was expecting to find the 'magic bullet'
> > for this problem here, but I was hoping that there might be some fping
> > wizard out there some magic bullets to spare.  Anywho, thanks for your
> > thoughts, Henrik.  I'll poke some more at the fping code and see if
> > I can figure out whats going on (I doubt it)
> 
> I haven't spent much time looking at the fping code, so I have no idea
> how well it's been optimized. It might be an idea to compile fping 
> with profiling enabled (i.e. add the "-g -pg" options to the compile- and
> link-flags) and run it through your test. This generates a "gmon.out"
> file which you can run through gprof like "gprof fping gmon.out" and
> it will tell you how much time is spent in various parts of the code.
> "gprof -l ..." will do it on a line-by-line basis.

I've had a look at the fping sources.

There aren't any really obvious reasons why it should take so long.
If you run it with "time", it also claims that the user- and system-time
are really low (I tried with ~1500 hosts), but the wall-clock time is
like 90 seconds (default options). Which kind of points at the code 
not really doing parallel pings.


I think I'll try some modifications to it over the week-end. If any of
it seems to improve it, I'll let you know.


Regards,
Henrik