Re: [PATCH 0/5] tcg: Dynamically allocate temporaries

[Philippe Mathieu-Daudé]

On 1/20/21 12:06 AM, BALATON Zoltan wrote:
> On Tue, 19 Jan 2021, Richard Henderson wrote:
>> My recent change for caching tcg constants has, in a number of cases,
>> overflowed the statically allocated array of temporaries.  Change to
>> dynamic allocation.
> 
> This seems to work for me so
> 
> Tested-by: BALATON Zoltan <balaton@eik.bme.hu>
> 
> but have you done any performance tests to check that this actually
> improves emulation speed? To mee it seems slower. Booting AmigaOS on
> sam460ex with c0dd6654f207 (just before your TCG series) takes:
> 
> real    0m33.829s
> user    0m34.432s
> sys    0m0.296s
> 
> but on HEAD with this series:
> 
> real    0m44.381s
> user    0m46.058s
> sys    0m0.532s
> 
> This is noticable decrease in speed also without measuring it. With just
> increasing the TCG_MAX_TEMPS to 2048 on 7c79721606be without this series
> I get:
> 
> real    0m42.681s
> user    0m44.208s
> sys    0m0.435s
> 
> So the performance regression is somewhere in the original series not in
> this fix up series.

Cc'ing Lukas for the performance part, as he is investigating
how to catch such regressions.

>> I'll note that nothing in check-acceptance triggers this overflow.
>> Anyone care to add some more test cases there?
> 
> The proposed test for the upcoming pegasos2 machine may also catch this
> (when that will be merged, its dependencies are still under review)

What are your running on pegasos2?

> or
> the sam460ex test that currently only checks the firmware could be
> enhanced to try to boot AROS if somebody wants to do that. The drawback
> is that it needs an external iso whereas the current test doesn't need
> any additional images but it did not catch problems with IRQ and neither
> this problem with TCG temps.

So this other option is not very useful, right?