Will OS4 have SMP after all

[wawrzon]

... especially on an OS as efficient as AmigaOS.

neither genuine amiga nor os4 i guess is so efficient in general as to justify that always repeated mantra. that about as true as that amiga is the best computer. there are areas where amiga is efficient in comparison to hardware it runs on, in particular on low memory machines with low res planar displays. but hardly there where all is based on linux ports anyway. everywhere where it is the case it will be about as efficient as genuine linux components or less, depending on quality of port.

[wawrzon]

I call myself the AmigaOS Development Team Lead for AmigaOS.

I'm not going to play these games. When it's done I'll tell you more.

i see a room for improvements in that title. for instance "his truly enlightened" or so.

[wawrzon]

I heard Bernd will be there this year.

bernd meyer? is he cooking something too? thats news, also i thought spilling the beans is disencouraged.

[wawrzon]

@fats
interesting, how is the situation on aros? is there also as heavy usage of forbid/permit or has it been replaced with something else at least partly, im curious?

[wawrzon]

i just looked and cant find any occurrences of forbid() in aros source itself..
so it could likely only be found in particular legacy 68k code, which doesnt matter till someone will develop 68k smp accelerators for amiga, and even then it will only be a handicap of particular application that halts the whole system while executing own code, which is anyway (meant as) hacking away the multitasking..

so good news,apparently.. aros is smp ready..

[wawrzon]

It is actually easy with MMU.

again, the only architecture not guaranteeing mmu will probably be 68k, which isnt multicore by definition at least for the expectable future. aros could solve it by some ifdefs.

[wawrzon]

If current amiga ng os systems can't do smp then say goodbye and reboot to ng/2

or maybe ar** v1?

Include something to run 68k apps, and ng apps in some kinda sandbox and move on...

uae is a sandbox, isnt it?

[wawrzon]

It would be nice not to have to resort to UAE.

why? legacy code needs 68k emu anyway. uae/68k code may be treated as java of amiga world. one could push uea integration forward with some intelligent ideas. for instance perhaps it is possible to fire up only the 68k emulation and very necessary uae features first, on run of the 68k program to spare cpu power, then as soon as (and if at all) the program makes any call to amiga chipset features those could be dynamically thrown on in emulation.

The biggest problem you're going to have is the need to halt the other cores when the one running AOS wants to execute a Forbid().
Its the simplest way to prevent a crash.

apparently not an issue on aros anymore (waiting for confirmation), but may have to be improved, i still observe issues on 68k now and then, not knowing if they may be related.

MorphOS will face a similar problem, but the developers are seriously considering dropping legacy compatibility.

at the point all three systems will want to go for those extended features that will likely set them on the same level of backward compatibility aros is now, namely uae. lets face it.

[wawrzon]

You are always going to have to have forbid() (and also disable()), and it is probably always going to be a nasty big lock over the whole system because that's part of the AmigaOS API and old Amiga program's expect it... But what you can do is "depreciate" the function, that is to say remove it from the API documentation and give developers other more fine grained locking mechanisms... That way it stays for compatibility, but is only used in some horrible old app that hopefully will be replaced with something nicer :-)

but i wasnt able to find any forbid() in aros v1 source yesterday, can you point me to an occurence, so that i have even the slightest idea about the issue?

[wawrzon]

Funny thing is that if AROS would also go this "NG/2"-route, then a 68k "distro" of this version/branch of AROS would also have to use UAE for legacy Amiga 68k apps, even when running on a real 68k Amiga! (Not that there are a great deal of 68k Amigas with multiple CPU's :lol:, but the "NG/2"-differences in the OS itself would require it)

personally i think it will have to be dealt with at the proper time, that means when it will become an issue. it has been also already talked of. possible solution is of course fork aros for 68k and update it from the main tree only where it is appropriate. something like that happens already, when krzysztof ports features from experimental aros v1 to public v0. v0 will never become v1, but will gain some of its portable features for the time being.

[wawrzon]

@bloodline:
ah, find them now, not sure why i missed them yesterday.