@Trev

You might be right there, but Amiga is best remembered for having the best Pre-Emtive Multitasking, which is a well-known fact weither or not it was the first..

@All

The thing about multitasking as not meant as an irony, but simply a matter of fact, expect perhaps weither or not the Amiga actually was the first to provide it..

I am also aware that AmigaOS needs som heavy work to be able to provide Multi-core support, but it doesn't mean it's not possible to make that become a reality. It only demands some hard work and time to make it, so all in its' time..

_________________
Probably Pegasos 2 G4 1Ghz 1GB DDR-system, ATI Radeon 9250, ESI@Juli PCi-soundcard, all running
AmigaOS 4.1 with latest updates, or a new powerful
Amiga! Fingers crossed!

@HKvalhe

Exec's scheduler was primitive compared to its Unix contemporaries, exceptional for its cost and target market, not its capabilities. We cherish it nonetheless.

EDIT: I think we'd see more rapid advancement in AmigaOS if the powers that be were given leave to drop support for legacy software.

Last edited by Trev on 11-Sep-2009 at 02:29 AM.

_________________
Sam440ep-flex 733 MHz/1 GB RAM/Radeon 9250/AmigaOS4.1 Update 2
borked A1200/Blizzard1260+SCSI-IV/Z4+MediatorZIV/Deneb/Voodoo3/CatweaselMk3
more borked A1200/MBX1200z/Indivision
A500/clockport/RRNet
A600/A603

@HKvalhe

Quote:

You might be right there, but Amiga is best remembered for having the best Pre-Emtive Multitasking, which is a well-known fact weither or not it was the first..

Heh... I remember when Amiga fanatics ####ed off Linus Torvalds and Linus went to say that Amiga multitasking is only co-operating (like Windows 3.1) because apps can disable it at any time by calling Forbid()

_________________
Amiga Developer
Amiga 500, Efika, Mac Mini and PowerBook

@Georg

I also like the idea of telling exec that "now I'm entering core-safe code" and "now I'm exiting". It's should be an easy first step which would allow Exec to schedule tasks in core-safe mode on any CPU. In the future these functions could simply be deprecated dummies and everything will be made core-safe by the system.


About libraries: I think they are the least problem here. Libraries are (typically) not tasks and they are all reentrant so what's the problem really (with some specific exceptions/hacks of course)?

Same with devices. They are tasks but you send messages to them, so what is the problem if messages were sent from other cores (providing the msging system is made safe by exec of course).

_________________
- Don't get fooled by my avatar, I'm not like that (anymore, mostly... maybe only sometimes)
> Amiga Classic and OS4 developer for OnyxSoft.

@HKvalhe

Quote:

HKvalhe wrote: @Trev You might be right there, but Amiga is best remembered for having the best Pre-Emtive Multitasking, which is a well-known fact weither or not it was the first..

Ok let's make a compromise
"You remember the Amiga for having the best Pre-Emptive Multitasking"

If someone wants to have Multicore support for the AmigaOS there are 3 possible ways:

1. The AmigaOS only runs on one core, a slave system is running on the others cores/CPUs that system has an own scheduler and exec interface to communicate with AmigaOS and gets its tasks, memory and data from the AmigaOS via specific function calls. ( Asymetric Multi Processing / other cores are only coprocessors)

2. Take a kernel that does SMP, create a new SMP/VM enabled API and setup AOS boxes that runs in a virtual memory area. That is the way Anubis is going. But it means "throwing away most AOS3 code or APIs.”

3. The AmigaOS only uses one core, the others don't do anything, but “Hey it runs on a multicore system”

_________________
AmigaONE. Haha. Just because you can put label on it does not make it Amiga.

I borrowed this comments from here (#27 & #28):
http://amigaworld.net/modules/newbb/viewtopic.php?topic_id=38873&forum=2&start=20&order=0

@Trev

Quote:

I think we'd see more rapid advancement in AmigaOS if the powers that be were given leave to drop support for legacy software.

Isn't that exactly what was done?

I mean, I don't think AmigaDE / Amiga Anywhere had ANY backwards compatibility with Classic AmigaOS?

@Trev and all

I am sure that Hyperion has a lot of interesting stuffs to work on. If someone can make it, it would be the Hyperion team..

_________________
Probably Pegasos 2 G4 1Ghz 1GB DDR-system, ATI Radeon 9250, ESI@Juli PCi-soundcard, all running
AmigaOS 4.1 with latest updates, or a new powerful
Amiga! Fingers crossed!

@Jupp3

I meant Hyperion, but yes, that's what Amiga, Inc. attempted. AROS, too. And one of the number one complaints with AROS is an inability to run m68k software natively. :-/

@HKvalhe

I'm sure they can, but that doesn't appear to be their focus--at least, not in public.

_________________
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borked A1200/Blizzard1260+SCSI-IV/Z4+MediatorZIV/Deneb/Voodoo3/CatweaselMk3
more borked A1200/MBX1200z/Indivision
A500/clockport/RRNet
A600/A603

@Arko

Quote:

Because AmigaOS uses shared systems structures that are not protected against other CPU accesses. SMP is impossible with AmigaOS.

Not fully true. As AmigaOS has pre-emptive multitasking you already have to protect the access to the data properly. The problem is in the protection itself. Most of the time Forbid() is used for this; even the Semaphore code uses Forbid() internally.
When using Forbid() a task assumes no other task can do anything until Enable(). On a multi-core/SMP system this means stopping all tasks on all cores/CPUs. So on a dual core you may be able to gain some speed but on more cores you won't gain anything; probably loose speed due to the overhead of the constant disabling/enabling of tasks on all cores/CPUs.

greets,
Staf.

@Fats

Quote:

Not fully true. As AmigaOS has pre-emptive multitasking you already have to protect the access to the data properly. The problem is in the protection itself. Most of the time Forbid() is used for this; even the Semaphore code uses Forbid() internally.

Some implementations do but you can have Forbid() free SignalSemaphores of course.

_________________
Amiga Developer
Amiga 500, Efika, Mac Mini and PowerBook

So: is there an efficient way to support multi-core with current OS ? Or do we need a new os/kernel (meaning: losing compatibility) ?

And I mean efficient way...

Last edited by Leo on 11-Sep-2009 at 09:15 PM.

_________________
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@Leo

Move the legacy AOS into a sandbox.

_________________
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Amiga 1200 (Rev 1D1, KS 3.2, PiStorm32lite/RPi 4B 4GB/Emu68)
Amiga 500 (Rev 6A, KS 3.2, PiStorm/RPi 3a/Emu68)

@Trev

Quote:

Trev wrote: @Jupp3 I meant Hyperion, but yes, that's what Amiga, Inc. attempted. AROS, too. And one of the number one complaints with AROS is an inability to run m68k software natively. :-/

Refer to http://o1i.blogspot.com/

_________________
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Amiga 1200 (Rev 1D1, KS 3.2, PiStorm32lite/RPi 4B 4GB/Emu68)
Amiga 500 (Rev 6A, KS 3.2, PiStorm/RPi 3a/Emu68)

@Hammer

That's cool, but my point was the conflict between a desire to move forward and a desire to hold onto the past. It's been almost thirty years, and Microsoft is finally dropping support for MS-DOS in its consumer operating systems. Maybe we'll see the same thing happen in Amigaland in another five or so years.

_________________
Sam440ep-flex 733 MHz/1 GB RAM/Radeon 9250/AmigaOS4.1 Update 2
borked A1200/Blizzard1260+SCSI-IV/Z4+MediatorZIV/Deneb/Voodoo3/CatweaselMk3
more borked A1200/MBX1200z/Indivision
A500/clockport/RRNet
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@Trev

"cmd.exe" is still included with Windows 7 RTM, but it's not the core OS.

_________________
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Amiga 1200 (Rev 1D1, KS 3.2, PiStorm32lite/RPi 4B 4GB/Emu68)
Amiga 500 (Rev 6A, KS 3.2, PiStorm/RPi 3a/Emu68)

@Hammer

I was talking about NTVDM, which isn't present in 64-bit versions of Windows (but only because VM86 mode isn't available in 64-bit long mode). In truth, Microsoft still distributes and supports (to some extent) MS-DOS, but unless you're a developer or OEM, you're out of luck.

EDIT: Is there anyone out there that actually believes cmd.exe is the "core OS" behind Windows NT? Scary.
EDIT2: I've been using Windows NT and its derivatives in various capacities (user, developer, administrator, architect, monkey, et al) since 1995.

Last edited by Trev on 11-Sep-2009 at 10:49 PM.
Last edited by Trev on 11-Sep-2009 at 10:42 PM.

_________________
Sam440ep-flex 733 MHz/1 GB RAM/Radeon 9250/AmigaOS4.1 Update 2
borked A1200/Blizzard1260+SCSI-IV/Z4+MediatorZIV/Deneb/Voodoo3/CatweaselMk3
more borked A1200/MBX1200z/Indivision
A500/clockport/RRNet
A600/A603

Quote:

EDIT: Is there anyone out there that actually believes cmd.exe is the "core OS" behind Windows NT? Scary.

Well, I guess a lot of people here are kinda stuck in the past with OS3.x being multitasked, Windows being run on top of DOS/Command.com, and MacOS having cooperative multitasking... This explains this kind of remarks :)

(Un)Fortunately, it's not the case anymore... and the only one stuck in the past, is the Amiga...

_________________
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@Trev

Quote:

I was talking about NTVDM, which isn't present in 64-bit versions of Windows (but only because VM86 mode isn't available in 64-bit long mode). In truth, Microsoft still distributes and supports (to some extent) MS-DOS, but unless you're a developer or OEM, you're out of luck.

I'm in luck....

Anyway, Windows 7 Pro/Ultimate supports VirtualPC/Windows XP mode.
http://www.youtube.com/watch?v=eNFczLYBtrA

Quote:

EDIT: Is there anyone out there that actually believes cmd.exe is the "core OS" behind Windows NT? Scary.

Windows NT core doesn't *use* X86-16 instruction set i.e. recall Pentium Pro's issues with 16bit instructions.

Last edited by Hammer on 12-Sep-2009 at 01:18 AM.
Last edited by Hammer on 12-Sep-2009 at 01:12 AM.
Last edited by Hammer on 12-Sep-2009 at 01:08 AM.
Last edited by Hammer on 12-Sep-2009 at 01:01 AM.
Last edited by Hammer on 12-Sep-2009 at 12:57 AM.

_________________
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Amiga 1200 (Rev 1D1, KS 3.2, PiStorm32lite/RPi 4B 4GB/Emu68)
Amiga 500 (Rev 6A, KS 3.2, PiStorm/RPi 3a/Emu68)

@Hammer

The Windows XP Mode stuff is interesting, but man, what a fail for Microsoft. At least they're keeping their virtualization guys busy. I'm glad I'm no longer in the desktop engineering/architecture game. In truth, I'd like to be out of the Windows game completely (from a support perspective only--I have no problem using Windows to do the things I like to do, like programming, gaming, and running WinUAE), but it pays the bills.

_________________
Sam440ep-flex 733 MHz/1 GB RAM/Radeon 9250/AmigaOS4.1 Update 2
borked A1200/Blizzard1260+SCSI-IV/Z4+MediatorZIV/Deneb/Voodoo3/CatweaselMk3
more borked A1200/MBX1200z/Indivision
A500/clockport/RRNet
A600/A603