Memory Management in AmigaOS4.0 Explained

[Legerdemain]

Hm. Okay, the way it was written made me misinterpret the sentence.

"the system". So they refer to "the system used" as simple. But then I would have written it like "the system used, to allocate areas of unused memory to new tasks, was pretty simple.". Without using "," before and after "to allocate areas of unused memory to new tasks" I don't really find it an easy read.

So... "was pretty simple" is now what determines how "the system used to" should be interpreted. Since it on the first read could easly be interpreted as someting like "(once upon a time) the system did allocate memory", until reaching the end of the sentince, instead of "the system (that was) used to" I would still say that it is a rather vague sentence. I think at least SOME of my past english teachers would agree with me...  :lol:

[Tigger]

Ah, better? Doesn't look like Tigger is too impressed.

--------------------------------------------------------------------------------

Kenny and Joanna too. There's a shock.

Perhaps they should rename it GroundhogBunny - same shyte over and over and over and over and over....

Gee Uncharted can you explain to me why you are impressed by OS 4 using slab, and please inform us all about the first time you knew you were using a slab memory system, and why you think its a great and innovative system for use in OS4.    
    -Tig

[Tigger]

So what on earth is the magical MorphOS mechanism that beats out slab allocation?

I actually don't know (or even care) how MorphOS does it, probably still like the Amiga used to do it, though its possible they may have some Slab like implementation.  My issue is this, when I started using computers, at which point most of the guys from Hyperion were breast feeding or not yet born, computers didnt have moniters, you typed a line it showed up on the piece of paper if you were lucky, we also had cards, but thats another story.   Moniters for terminals were a big technical innovation, they came after the theory of slab programming, which is used in XP, Linux, (huge list of OSs deleted).  Its not innovative for an OS to take an idea older then the amiga computer and which is used by everyone else as our memory management system, its ok to do that, but dont write an article about the innovation of the memory system, when its just like everyone elses.  Any real technical person is going to look at that article, laugh at it (as I did) and say why should I use this OS, especially as poorly described as the system is.  Someone said the site is for OEMs to look at, I hope not, no OEM is going to look at those first two articles (Ram Disk and then new Slab article) and think that they want to use this OS on there hardware, and since it doesnt run on any manufactured hardware at all now, it doesnt really have a market anyways.  
    -Tig

[dylansmrjo]

Yeah, I sort of figured I could actually click on links :crazy:

Very interesting reading. I was a bit surprised to see it was based on a technology used (and created) by Sun and used in Linux as well. We are talking major OS'es here - especially on servers.

Perhaps Amiga OS4 developers suffers from grandeur  :lol:

No just kidding. I like it. I really like this.

[dylansmrjo]

Well, you can always get an microA1 - they are actually available and ships with a pre-release of AOS4.

I've notice you like to flame AOS4, and go ahead. If that makes you life easier, then be my guest.

The rest of us will be pleased to see AOS4 using techniques from the large OS'es rather than an outdated primitive technology which was known to be bad at the time it was implemented.

It's not innovative, but that's not the point. What's interesting is that we get some description of the system, though in a very light edition.

[Plaz]

and please inform us all about the first time you knew you were using a slab memory system, and why you think its a great and innovative system for use in OS4.

Oh man, I hate that. A pop quiz.
I guess it's inovative that OS4 will include it when it hasn't before? But since (as you mention) it's a model that's being used in other OS's, it's not really new. I also notice from my reading that red hat implements slab in concert with MMU and a zoned buddy allocator. Since OS4 doesn't have these extra components at it's disposal, could it be called innovative when they get it to work without an MMU? Go easy please. I'm no expert, just musing through the data and try to make some sence.

Plaz

[Tigger]

Well, you can always get an microA1 - they are actually available and ships with a pre-release of AOS4.

Actually there not, and havent been for months, but hey try again.  If you want to argue this point, please inform me the name of a dealer where I can buy an Amigaone today and get it fedexed to me.  AmigaOnes are nat available now, and won't be available in the future.  This is the real problem with OS4, the other one is that HYPErion is trying to live up to its name even though they dont have anything they can sell as the moment.

I've notice you like to flame AOS4, and go ahead. If that makes you life easier, then be my guest.

I flame idiots, you are getting close to playing in fire now, Hyperion is taking a very old Memory management idea and trying to jam it into the Amiga system, its likely to be slower, and not offer alot of benefit.  I and others have doubts whether they have actually implemented it in this manner now, and fear this system will break lots of current software.  

The rest of us will be pleased to see AOS4 using techniques from the large OS'es rather than an outdated primitive technology which was known to be bad at the time it was implemented.

Why exactly do you believe that the current system is either primative or bad??   Its worked for a long time, and given the way the Amiga works, it definitely had advantages over what Hyperion claims they are doing for OS4.
    -Tig

[adolescent]

@Plaz

could it be called innovative when they get it to work without an MMU?

Are you saying OS4 doesn't use the MMU?  Why not?

[uncharted]

Gee Uncharted can you explain to me why you are impressed by OS 4 using slab,

I never said I was impressed, in fact I never commented on the system itself.

 and please inform us all about the first time you knew you were using a slab memory system,

Who says I am using a slab memory system?

 and why you think its a great and innovative system for use in OS4.    

I never said I thought that.

You must be confused, I was commenting on my lack of surprise at the responses posted by you and others.

[SHADES]

I find myself reading those OS4 pages over and over
I thought it was well written and explained. I got a lil confused with the byte shifting for CPU cache part but appart fromthat, i found it very imformative.

[dylansmrjo]

If you want to argue this point, please inform me the name of a dealer where I can buy an Amigaone today and get it fedexed to me.

Well, I know of at least 3 dealers in Scandinavia and Northern Europe who are capable of shipping mikroA1. There are however no AmigaOne's but there are mikroA1's to get (at a rather high price due to the unfortunate low production).

I don't know about the situation in USA and I really don't care. Whatever goes on overthere makes no impact on my life.

I flame idiots, you are getting close to playing in fire now, Hyperion is taking a very old Memory management idea and trying to jam it into the Amiga system, its likely to be slower, and not offer alot of benefit. I and others have doubts whether they have actually implemented it in this manner now, and fear this system will break lots of current software.

Well, then you ought to start flaming yourself. The management system is a tad old, but it's fine in many OS'es, and there is no reason it shouldn't work fine in AOS. It is way better than the old system, which resembles the memory management in Win9X way too much.

The old way was wrong even in 1985. It works but so does a Trabant. It doesn't make it a good car, though. Nor is the old system good in any way.

The amount of software for OS4 is minimal and any broken software can easily be repaired, unless it is coded in crappy way. However, nothing seems to indicate it would break anything. You're just trolling as usual.

Why exactly do you believe that the current system is either primative or bad?? Its worked for a long time, and given the way the Amiga works, it definitely had advantages over what Hyperion claims they are doing for OS4.

The old system is bad because it wastes too much memory and is inflexible. As I wrote in the former paragraph it looks a lot like other outdated and long time since replaced systems.

Don't look at AOS4 with your eyes on a 20 year old Amiga. Look at it with your eyes on more modern hardware (though the mikroA1 is using some pretty dated technology - at least the Peg2 is using DDR-RAM).

[JoannaK]

Uncharted: Ah.. this thread explains all those funny messages that suddenly appeared on MB... I was wonderhing how those people were so suddenly become interested on that site.  :-P

Yeah.. I don't think they (Hyperion) should be hunting new Buzz.Phrases for their OS.. They are allready way too late on fixing critical bugs and delivering the OS, so trying to implement this kind of 'high-tech' stuff only delays it further.

And please do note... word high-tech is on quotes in purpose.. This Slab-allocator (even though itself has certain adwantages over The Amiga way) will not be any miracle cure for underlying problems of their OS (and system in whole), it's just something Flashy they found up on net and decided that it would look cool enough to introduce on website in purpose on buying some time, before the few remaining user's loses their interest.

[AmigaHeretic]

@Tigger

My issue is this, when I started using computers, at which point most of the guys from Hyperion were breast feeding or not yet born, computers didnt have moniters, you typed a line it showed up on the piece of paper if you were lucky, we also had cards, but thats another story. Moniters for terminals were a big technical innovation, they came after the theory of slab programming, which is used in XP, Linux, (huge list of OSs deleted). Its not innovative for an OS to take an idea older then the amiga computer and which is used by everyone else as our memory management system, its ok to do that, but dont write an article about the innovation of the memory system, when its just like everyone elses.

Maybe you should check out what is written and "being presented" before you make an ass of yourself.

The VERY first refence link "[1] The Slab Allocator: An Object-Caching Kernel Memory Allocator (1994)" shows the date "1994".  If you looked at that you see in the first section for "Citations" is a link to "The Art of Computer Programming (context) - Knuth - 1968"  Yeah that's right "1968"!!

I mean clearly they don't want you to know this has been around for a long time, clearly they want you to think they invented it, it's plainly obvious this is just marketing and they are trying to hide the truth.  CONSPIRACY!! I say.

AmigaGuy  :roll:

[AmigaHeretic]

@JoannaK

before the few remaining user's loses their interest.

Get a grip.  We haven't EVER had memory proctection.  We haven't had it for 20 years!!  If you're still an "Amiga" user it's probably not, after all these years, going to make any difference if they implement it now, in the future, or ever.  I highly doubt this is to "keep the few remaining users", that's as absurd as it gets around here.  

AmigaGuy  :lol:

[JoannaK]

Amigaguy: Well. I was not thinking about memory protection(*) while I was writing that comment... There are a lot more pressing and critical problems they have not been able to solve in last three or so years. Memory protection won't be the key issue on determing the OS4 future..

(*) It's an  real *old* (we thought that a lot in those days as first Turbo cards with MMU:s appeared for A2000, so it must be at least 10 years old debate) and well known issue that one can't make decent memory protection without breaking Amiga Message passing system entirely (or slowing it down to grinding halt). So I didn't even expect them to be able solve that part of the puzzle on OS4..   :-)

[Rob]

@JoannaK

Why does OS4 even matter to you.  If it's so bad why even bother to comment?