Re: [Freedos-user] FreeDOS is slow in Raspberry 4

[Rugxulo <ru...@gm...>]

Hi,

On Fri, Mar 20, 2020 at 4:03 PM Swap Jim via Freedos-user
<fre...@li...> wrote:
>
> Tried it. Didn't change anything. But thanks for the suggestion.

I don't think debug info is loaded into RAM at all. I'm not sure if
even DJGPP does that either. So don't worry about that (much).

I don't think "-O3" is reliable. In fact, you could go crazy trying a
million different options. (Try asking Gentoo users on IRC, maybe
somebody will help.)

I have never used any R-Pi machines, but I would naively suggest "-s
-O2 -finline-functions -fomit-frame-pointer -mtune=native".

But, honestly, QEMU is just slow. It's okay for simple stuff, but you
really suffer on more complex things. Not complaining! Anything is
better than bugs (or no compatibility at all!). Hardware VT-X (KVM)
helps a ton. Not sure what ARM supports for that.

Well, you could (weakly) try my MetaDOS floppy image. (I may need to
update it, yet again, one of these weeks.) It's fairly simple and
doesn't need any major installing. So simple networking should work
okay via packet driver. It has various tests you could try, just to
see how long it takes to complete. It's far from perfect, though. Try
doing some simple compilations: "tests /t oberon" or "tests /t
turpas32" or "tests /t nasm98dj" or "tests /t invaders".

* https://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/unofficial/metados/


> On 2020-03-19 05:48, Louis Santillan wrote:
> >
> > `-g` [0] adds debugging info which will make the QEMU binary larger,
> > and produce code & data to allow instrumenting and debugging at
> > runtime.  This will blow cache performance since more code & data
> > overflow the cache.  I recommend removing this all together.
> >
> > I recommend trying `-O3` or `-Ofast` without `-g` and retesting/rebenchmarking.