[hatari-devel] Profiling Hatari code with Valgrind

[Eero Tamminen]

Hi,

On perjantai 07 tammikuu 2011, David Savinkoff wrote:
> I've been playing with Falcon emulation and using 'top' on my slow
> system P3 1GHz. My opinion is that the dsp has been optimized so
> good that there are diminishing returns in optimizing it further.
> The problem is more in the rest of the falcon emulation. For example,
> when I run Fractal Flight with the dsp I get my system max'd, then
> when I switch the dsp to off or dummy my system is still max'd but
> the fractal flight continues at the same slow speed until there is no
> data for the screen. Removing the dsp effectively makes no speed
> difference!

That sounded very peculiar so I checked the code.

Disabling DSP from the UI doesn't do anything unless you save that
setting and restart Hatari, e.g. rebooting it isn't enough.  I.e. your
observation isn't valid.


That's because the code does this:
----
void DSP_UnInit(void)
{
#if ENABLE_DSP_EMU
        if (ConfigureParams.System.nDSPType != DSP_TYPE_EMU)
                return;
----

(DSP_UnInit() can be called only when DSP emulation is enabled,
so above means that DSP will never be uninitialized.)


> One other whacky bug I get with hatari is sometimes a key is repeating
> at boot time.

AFAIK that's a TOS issue, not Hatari one and it happens on real Atari
machines too (I think it's been discussed on the MiNT mailing list).


> I've noticed that when this happens while booting the falcon,
> the emulation gets severely loaded, and stays that way (not a
> dsp issue).

If you press key again, the repeating should stop.


	- Eero