Re: gdmgreeter CPU usage

[Federico Mena Quintero <federico ximian com>]

On Wed, 2006-01-11 at 09:05 +0000, Padraig O'Briain wrote:
> FcFontSort is called 12 times during gdmgreeter startup, with a total
> cost of 205 ms of CPU.
> 
> As this occurs during the boot phase I suspect that the elapsed time is
> even longer.
> 
> I have bootchart that show that gdmgreeter takes about 5 seconds to
> startup when booting. About 860 ms of that is CPU time.

Ah.  Now we are getting somewhere :)

I haven't looked at the dtrace log you posted - I assume it has a
breakdown of the user time for various parts of gdm?

Even though FcFontSort is only 4% of gdm's startup time, it will affect
all GNOME apps at startup, since each of them has to invoke it several
times.

- Do we really need to call it 12 times?  Just how many different font
descriptions does gdm use?

- Given the same parameters, does the function always return the same
value?  I don't want to put in a cache prematurely, but this would be
useful to know.

- Can we get a little program that runs FcFontSort in a loop so that we
can profile it?

  Federico