[SDL] DirectX 7?

David Olofson david.olofson at reologica.se
Mon Sep 30 08:19:01 PDT 2002


On Friday 27 September 2002 14:30, Neil Griffiths wrote:
[...]
> Linux is NOT a desktop OS. It is a server OS. It is NOT designed for
> desktop tasks, it is not designed for games, it is not designed for
> office work - it's designed to handle consecutive tasks/users and to
> be as stable as possible.

Yeah, we all know by now that desktop OSes should *not* be stable, nor 
multitask properly. ;-)

(Sorry, couldn't resist! :-)


> I never said you can't use it on your
> desktop, but that doesn't make it a desktop OS. The fact that people
> have produced office applications and games for it doesn't make it a
> desktop OS, it means people have worked with what they have. Have you
> seen the problems you can have trying to work with timers, sound and
> graphics under Linux?

Most of this is because of poor drivers and lack of APIs to make use of 
existing features - not becaues of limitations of the kernel.

Yes, we are indeed talking about a kernel designed for servers, but that 
doesn't mean it's inherently broken when it comes to other tasks. Indeed, 
it *used* to be in some regards, and it still hase some minor issues, but 
those are issues that start to affect high end servers as well, and 
consequently, will be fixed in 2.6/3.0, or have been fixed already.


> You can do it, but doing it quickly and
> accurately is going to be a problem while Linux is designed for server
> applications.

Well, for the record, I've always had much more trouble with audio on 
Windows than on Linux... Even standard Linux does 10-20 ms pretty 
reliably, but I've never managed to get below some 50 ms on Windows. 

And let's not talk about Linux/lowlatency...


> When you find Linus and all the other people under him working on
> making a kernel which allows access to timers and access to sound
> which isn't through a file-like system -

So mmap() and ioctl() based interfaces, optionally wrapped in thin 
interface libs won't work? You just *have* to screw the whole 
kernel/system interface up to get decent multimedia performance?

I beg to differ.


> and allows access to your
> graphics card (even if through a wrapper to reduce the risk of
> crashing) -

A wrapper does not reduce the risk of crashing significantly. Only 
client/server or kernel driver based designs can do that. Indeed, the 
former is not too great for games, and I think Linux has failed to 
present anything truly useful of the latter kind. That's not an effect of 
the read()/write()/mmap()/ioctl() interface, though.


> only THEN will Linux start to become a desktop OS,

When the remaining scheduling latency issues have been fixed, and fbdev 
has turned into something truly useful, I don't think there's much more 
that needs to be done, actually. Sure, timers utilizing the full APIC or 
PIT resolution would be cool, but with HZ == 1024 or something on all 
workstation hardware, it's no big deal if it's ruled out for performance 
reasons. The RTC is still there, and happily generates up to 8192 Hz - 
and you'll need RTLinux or RTAI to make much use of that.


> but
> right now it is still being designed with server applications in mind.

Yes. I don't think that is a big an issue as you make it sound, though.


> And not you, nor anybody else, can change the fact that Linux is a
> server OS until that happens. You can use it on your desktop, but it's
> still designed as a server OS.

I agree, but not completely, and not with your idea of *how* Linux must 
change. I think it's possible to achieve decent multimedia performance 
without entirely ruining security and stability.

As to more traditional desktop applications, what's missing...? (Well, 
apart from the *applications*, that is. ;-)


> If you don't have anything else constructive to say, I actually wish
> you wouldn't reply to anything else I say. Hardly anything you've said
> has been accurate or useful so it's not like anyone is missing
> anything.

Looks like we have too much opinion and adrenaline here, and a lack of 
hard facts... Oh well. This is about operating systems, so it's to be 
expected. *sigh*


//David Olofson - Programmer, Composer, Open Source Advocate

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| The Return of Audiality! Real, working software. Really!  |
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`-----------------------------------> (Public Release RSN) -'
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