@cdimauro

Quote:

cdimauro wrote: @kolla: how much RT is Linux is yet to be seen.

It has been in use for like almost 20 years already, I have seen it in use in various time critical OT equipment over the last decade.

https://www.zdnet.com/article/20-years-later-real-time-linux-makes-it-to-the-kernel-really/

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@matthey

Quote:

Linux is maybe better for RT use than the AmigaOS is for desktop use

Only a few very particular use cases benefit from RT on the desktop, and they have all managed quite well _without_ RT on Linux desktop so far. AmigaOS works allright as long as there's no "disturbing software" in the way that sucks CPU time, such as various (P)IO drivers, IP stack, USB stack etc. For example, I was once working with a neuro-lab setup that included an A600 that was used to play animations triggered either by keyboard or by signal on the serial port from the unit that also started external clock and video recording of the experiment sample, So one single task, one single program, everything in RAM:, only rexxmast running in the background (to catch signal from serial port and start animation). This experiment is still running, with my old DPaint animations (!!) converted to some modern format, on Windows systems.

Quote:

but the AmigaOS has been hidden away and under developed

Understatement :) But really, there are much better options around now, and they have been around for a long time already.

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@matthey

Quote:

poor scaling of Linux like OSs

You don't realize how silly that sounds?

There's no other operating system that scales up and down, left and right, like Linux does (NetBSD is perhaps closest.)

Imagine - from the same source tree, you can build a kernel that runs on like 20 different architectures, from ancient lowend single core systems to latest greatest multiprocessor systems, symmetric and asymmetric, big and little endian, from just a few MB or RAM to hundreds (if not thousands) of GB with RAM, from tiny little embedded controllers to clustered supercomputers with thousands of nodes.... I mean, seriously - poor scaling?!

Last edited by kolla on 28-Nov-2024 at 02:44 PM.
Last edited by kolla on 28-Nov-2024 at 02:44 PM.
Last edited by kolla on 28-Nov-2024 at 02:43 PM.

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@kolla

Quote:

kolla wrote: @cdimauro Quote: cdimauro wrote: @kolla: how much RT is Linux is yet to be seen. It has been in use for like almost 20 years already, I have seen it in use in various time critical OT equipment over the last decade. https://www.zdnet.com/article/20-years-later-real-time-linux-makes-it-to-the-kernel-really/

I know it since long time, but... my question is still left without answer.

As I've said before, I'd like to see a benchmark with the relevant parameters of an RTOS tested, to have a measure and evaluate.
Quote:

kolla wrote: @matthey Quote: poor scaling of Linux like OSs You don't realize how silly that sounds? There's no other operating system that scales up and down, left and right, like Linux does (NetBSD is perhaps closest.) Imagine - from the same source tree, you can build a kernel that runs on like 20 different architectures, from ancient lowend single core systems to latest greatest multiprocessor systems, symmetric and asymmetric, big and little endian, from just a few MB or RAM to hundreds (if not thousands) of GB with RAM, from tiny little embedded controllers to clustered supercomputers with thousands of nodes.... I mean, seriously - poor scaling?!

This is achieved because a lot of companies invested tons of money on Linux, extending it for their needs.

Money allow to open many doors...

However, this does NOT mean that Linux is good for everything: it only means that it can and is used for doing those tasks.

You can see it on mobile: it's used for Android, which is a mammuth and requires a lot of resources. Whereas Apple's devices require much less hardware to give the users a similar experience.

A microkernel is way better at scaling, it's more modular (by definition), more robust, much lighter, safer.

I think that this is what Matt was trying to explain, before.

@kolla

Quote:

kolla wrote: @matthey Quote: poor scaling of Linux like OSs You don't realize how silly that sounds? There's no other operating system that scales up and down, left and right, like Linux does (NetBSD is perhaps closest.)!

*Ack*

From single core 40 MHz over multi core 4Ghz to massive parallel computer.

There might be niche for extreme small systems where even stripped down versions of Linux are to big.

kolla Quote:

You don't realize how silly that sounds? There's no other operating system that scales up and down, left and right, like Linux does (NetBSD is perhaps closest.) Imagine - from the same source tree, you can build a kernel that runs on like 20 different architectures, from ancient lowend single core systems to latest greatest multiprocessor systems, symmetric and asymmetric, big and little endian, from just a few MB or RAM to hundreds (if not thousands) of GB with RAM, from tiny little embedded controllers to clustered supercomputers with thousands of nodes.... I mean, seriously - poor scaling?!

Flexibility is not the same as scalability. Linux is flexible by using a broad range of patchwork and conditional compilation which is still considered Linux as long as the patchwork is "official". There are non-Linux OSs like the Zephyr OS that use Linux components. It would be Linux if the reduced API was an "official" option but it would have minimal Linux compatibility. The mainstream RT patches were made "official" but only for some architectures so non-RT Linux is official and potentially incompatible too. Is Linux still Linux to remove components and APIs to scale it down? Tiny embedded systems may not need much Linux compatibility but are users any better off with castrated Linux than other embedded OS options designed for a small footprint and RT use? There is good propaganda value to call a broad range of Linux derived software Linux as it makes Linux look more successful. I suppose some people consider Linux to be good at scaling down probably because it sets the free software standard but even castrated Linux distros use several MiB of memory for a CLI prompt and tens of MiB of memory for a GUI when the AmigaOS scaled as low as 256kiB of memory with a GUI and using less drive space than Linux. Maybe I'm just spoiled by the tiny footprint 68k AmigaOS where I get a GUI, standardization and binary compatibility of software avoiding the need to recompile everything. It is just too bad that there is no competitive 68k hardware available to leverage these advantages.

@matthey

Quote:

Flexibility is not the same as scalability. Linux is flexible by using a broad range of patchwork and conditional compilation which is still considered Linux as long as the patchwork is "official". There are non-Linux OSs like the Zephyr OS that use Linux components. It would be Linux if the reduced API was an "official" option but it would have minimal Linux compatibility. The mainstream RT patches were made "official" but only for some architectures so non-RT Linux is official and potentially incompatible too. Is Linux still Linux to remove components and APIs to scale it down? Tiny embedded systems may not need much Linux compatibility but are users any better off with castrated Linux than other embedded OS options designed for a small footprint and RT use? There is good propaganda value to call a broad range of Linux derived software Linux as it makes Linux look more successful. I suppose some people consider Linux to be good at scaling down probably because it sets the free software standard but even castrated Linux distros use several MiB of memory for a CLI prompt and tens of MiB of memory for a GUI when the AmigaOS scaled as low as 256kiB of memory with a GUI and using less drive space than Linux. Maybe I'm just spoiled by the tiny footprint 68k AmigaOS where I get a GUI, standardization and binary compatibility of software avoiding the need to recompile everything. It is just too bad that there is no competitive 68k hardware available to leverage these advantages.

Memory is cheap.

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@cdimauro

Quote:

cdimauro wrote: @kolla: how much RT is Linux is yet to be seen. And Zephyr as well.

Linux with RT extensions is good enough for Space X.

My home country of Australia (Gilmour Space) has an orbital class payload carrying rocket. Gilmour Space is aiming for human rated Eris Heavy.


NASA has multiple payload carrying launch rockets i.e.
Firefly Aerospace Alpha,
United Launch Alliance Atlas V (to be EOL),
United Launch Alliance Vulcan,
Rocket Lab Electron,
SpaceX Falcon 9,
SpaceX Falcon Heavy,
SpaceX Starship (WIP),
Blue Origin New Glenn (WIP),
Northrop Grumman Pegasus XL,



European Union/European Space Agency needs to fix thier very slow and expensive space program. European bureaucracy is LOL.

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@Hammer

Quote:

Hammer wrote: @cdimauro Quote: cdimauro wrote: @kolla: how much RT is Linux is yet to be seen. And Zephyr as well. Linux with RT extensions is good enough for Space X.

As we say in Italy, you discovered the hot water...
Quote:

My home country of Australia (Gilmour Space) has an orbital class payload carrying rocket. Gilmour Space is aiming for human rated Eris Heavy. NASA has multiple payload carrying launch rockets i.e. Firefly Aerospace Alpha, United Launch Alliance Atlas V (to be EOL), United Launch Alliance Vulcan, Rocket Lab Electron, SpaceX Falcon 9, SpaceX Falcon Heavy, SpaceX Starship (WIP), Blue Origin New Glenn (WIP), Northrop Grumman Pegasus XL,

Hammer's PADDING...
Quote:

European Union/European Space Agency needs to fix thier very slow and expensive space program. European bureaucracy is LOL.

The main problem of EU is that it's not a United States of Europe: it's a collection of states with common general laws about economy. There's no common defense, no common health system, etc. etc..

But at least we've a space program. What about your Australia?

Believe it or not - RT is mostly _not_ space programs!

It's used to control industrial robots and other industrial equipment
It's used in networking (for example Cisco IOS typically has an RTOS underneath, often Linux (especially in test), but also QNX etc)
It's used in traffic control systems
It's used in railroad control systems
it's used off-shore, on ships and oil rigs
it's used in aviation (not limited to flight controls)
it's used in all kinds of so called operational technology, such as monitoring of physical environments, such humidity/smoke/fire detection and alarming
the list can go on and on...

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@matthey

Quote:

Flexibility is not the same as scalability.

Then specify what you mean with "scalability"

Quote:

Linux is flexible by using a broad range of patchwork and conditional compilation which is still considered Linux as long as the patchwork is "official".

It's a matter of pragmatism - the exact same applies to _any_ operating system, they _all_ have compilation options.

Quote:

There are non-Linux OSs like the Zephyr OS that use Linux components. It would be Linux if the reduced API was an "official" option but it would have minimal Linux compatibility.

Well, it isn't Linux, is it.

Quote:

The mainstream RT patches were made "official" but only for some architectures so non-RT Linux is official and potentially incompatible too.

Yes, the RT patches still exists for remaining supported architectures (that's why I initially wrote "in the process of"), in time these too will be merged (if there's still incentive to support these archs at all)

Quote:

Is Linux still Linux to remove components and APIs to scale it down?

Yes, of course, this has always been the case, and again - for any OS - remove a component, and the API which this component provided will be gone too. Same with AmigaOS, that's how we have different kickstarts for the various Amiga models.

Quote:

Tiny embedded systems may not need much Linux compatibility but are users any better off with castrated Linux than other embedded OS options designed for a small footprint and RT use?

Quite often the answer here is yes, and RT isn't always even relevant.

Quote:

There is good propaganda value to call a broad range of Linux derived software Linux as it makes Linux look more successful.

What kind of argument is this? I promise you, the goal of the kernel developers is not to take over the world and have every single idiot out there as a potential entitled whining user - no, rather the contrary. It's the other way around, there are tons of people who specifically want to use Linux because it is pretty much the Swiss army-knife of operating systems. The kernel developers are becoming increasingly stricter with what can come into the kernel treee - the RT patches have been going on for 20 years already.

Quote:

I suppose some people consider Linux to be good at scaling down probably because it sets the free software standard but even castrated Linux distros use several MiB of memory for a CLI prompt and tens of MiB of memory for a GUI when the AmigaOS scaled as low as 256kiB of memory with a GUI and using less drive space than Linux.

What is "castrated Linux"? You scale down to meet the requirements from the hardware, the software and your needs. This is not "castration".

Quote:

Maybe I'm just spoiled by the tiny footprint 68k AmigaOS where I get a GUI, standardization and binary compatibility of software avoiding the need to recompile everything.

Is that why we have all these "optimized" builds for 020, 040, 060 with and without FPU, a range of GUI toolkits, incompatible variants of OS components etc?

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@kolla: let me copy & paste again, since evidently it wasn't clear before.


This is achieved because a lot of companies invested tons of money on Linux, extending it for their needs.

Money allow to open many doors...

However, this does NOT mean that Linux is good for everything: it only means that it can and is used for doing those tasks.

You can see it on mobile: it's used for Android, which is a mammuth and requires a lot of resources. Whereas Apple's devices require much less hardware to give the users a similar experience.

A microkernel is way better at scaling, it's more modular (by definition), more robust, much lighter, safer.

I think that this is what Matt was trying to explain, before.

@cdimauro

You’re not telling me anything I don’t know already, most of it is obvious.

But the examples and arguments that come up here are mostly false.

You bring up mobile phones and how much Android sucks over Apple iOS - I’m well deep into the Apple ecosystem myself and XNU - though with origins on Mach (which is a microkernel) - is not microkernel, it’s half-officially described as “hybrid� (as is Win NT, iirc)

I’m all in on the “microkernel is better�, believe me - I was eagerly advocating mach based systems, Minix, Hurd, NeXT, BSD lite, mkLinux, Neutrino and others.. but when I look around, they aren’t exactly widely used. Though it was fun to see how Minix was/is present on Intel ME, that’s probably the most widespread adoption I can think of.

Last edited by kolla on 01-Dec-2024 at 02:29 AM.

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@kolla but again, the discussion was pretty technical and had nothing to do with the wide spread or restricted usage of a kernel.

@kolla

Quote:

It's used in traffic control systems

2070 Advanced Traffic Controller example approved by CalTrans
https://www.mccain-inc.com/products/controllers/2070-controllers/2070lx-controller
It's Linux based with MPC8360E Freescale PowerQUICC II Pro.

Last edited by Hammer on 02-Dec-2024 at 01:03 AM.
Last edited by Hammer on 02-Dec-2024 at 01:01 AM.

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@cdimauro

Quote:

he main problem of EU is that it's not a United States of Europe: it's a collection of states with common general laws about economy. There's no common defense, no common health system, etc. etc..

EU has a common border policy, common reserve bank for Eurozone, common supreme court, and 'etc'.

https://www.infomigrants.net/en/post/61087/ecj-issues-opinion-on-italian-migration-case
ECJ (EU's supreme court) involved itself beyond the economy e.g. Italy's illegal migration issue.

On the illegal migration issue, Australia has implemented off-shore processing while Italy's version has ECJ interference.

Europe already common defense policy via NATO.

A reminder, an EU Army wouldn't have the backing of raw resource-rich USA and Canada.
A war of attrition is a logistics and raw resource war. France's EU Army push is in dreamland.

To match a fully mobilized Russia's raw resource advantage, NATO would need the backing resource-rich USA and Canada. Trump 2.0's XL Pipeline reboot is important for improving oil transport integration between the USA and Canada.

Australia and Japan are on the Pacific front. During WW1, UK's British Empire's raw resource strength comes from Canada, Australia and India.

In modern times, UK joins CPTPP which includes Canada and Australia. Thanks to Trump 1.0's exit from TPP, CPTPP was created.


https://www.defensenews.com/global/europe/2024/02/05/eu-member-countries-push-back-on-italys-call-for-european-army/

“NATO is the cornerstone of our collective security, and defense remains a matter of national sovereignty – there is no NATO or EU army, but close defense cooperation between allies and member-states,� the Danish defense ministry said in a statement. “Denmark does not support establishing an EU army.�


Quote:

@cdimauro, But at least we've a space program. What about your Australia?

Australia's economy and population are roughly equivalent to the entire Nordic countries https://en.wikipedia.org/wiki/Nordic_countries

Australia's land area is similar to mainland USA or China.

In partnership with the UK, Australia had space and nuclear weapons programs in 1950s.

Australia's modern space program is restarted in 2018 and it's partly bankrolled by Australia's large pension funds. Orbital class Eris Block 1 rocket is ready to be launched and recently obtained a launch permit.

Australia has CER agreement (mini-EEC like) with New Zealand.


From https://www.thinkingaheadinstitute.org/content/uploads/2024/02/GPAS-2024.pdf
Pension Funds (national saving fund policies) vs GDP ratio for year 2023

Five Eyes/Five Passport Group,
Australia: $2,448 billion, 145% (CPTPP member)
Canada: $3,105 billion, 146.6% (USMCA, CPTPP member)
United Kingdom: $3,206 billion, 96.2% (CPTPP member sometime in DEC 2024)
United States: $35,600 billion, 132.1% (USMCA member)
(I don't have data for New Zealand)

European Union
Finland: $284 billion, 93%
France: $155 billion, 5.1%
Germany: $586 billion, 13.5%
Italy: $243 billion, 11.1%
Netherlands: $1,737 billion, 159%,
Ireland: $172 billion, 29.2%
Spain: $43 billion, 2.7%
The EU lacks strategic savings coordination. UK's exit from the EU was a major blow on EU's strategic savings.

Large scale pension funds allows the government to issue government bonds with large scale bond buyers.

Non-EU, Europe
Switzerland: $1,361 billion, 150.3%

North America (not including the Five Eyes)
Mexico: $381 billion, 21% (USMCA, CPTPP member)

South America
Brazil: $272 billion,12.8% (BRICS member)
Chile: $199 billion, 57.8% (CPTPP member)

East Asia, South East Asia
China: $423 billion, 2.4% (BRICS member)
Hong Kong: $216 billion, 56.0% (BRICS member)
Japan: $3,385 billion, 80.6% (CPTPP member)
South Korea: $1,102 billion, 64.0%
Malaysia: $278 billion, 64.5% (CPTPP member)



Quote:

@cdimauro, Hammer's PADDING...

You can't handle the volume.

Last edited by Hammer on 02-Dec-2024 at 02:16 AM.
Last edited by Hammer on 02-Dec-2024 at 02:09 AM.

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