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Vanquish · Jun 12, 2002, 06:42 AM

Is Mandrake linux MP enabled at system level or only for apps that can use the 2 CPU's (as in OS9) ? (for a 9600/200MP)

-Vanquish

hidozage · Jun 12, 2002, 08:43 AM

<blockquote>quote:<hr />Originally posted by Vanquish:
Is Mandrake linux MP enabled at system level or only for apps that can use the 2 CPU's (as in OS9) ? (for a 9600/200MP)

-Vanquish<hr /></blockquote>I have not tested MP on a PowerMac since I don't have one. But, you can install Linux Mandrake for PPC and recompile the Linux kernel for MP support. This will give you MP support at system level. I know there is a debian MP kernel at <a href="http://www.ppckernel.org/debian-2.4-smp/" target="_blank">http://www.ppckernel.org/debian-2.4-smp/</a>

You can head down to <a href="http://www.ppckernel.org/" target="_blank">PowerPC Kernel Archive</a> to download the up-to-date builds of the latest PowerPC Linux kernel source trees.

Northform · Jun 12, 2002, 12:28 PM

I don't think that Linux will preform too well on an MP machine because of the design of its monolithic kernel which is unaware of threads and MP. Linux isn't really useful on MP hardware because it doesn't scale well. There are many projects going on right now to create better free kernels. These kernels could form the basis of a new GNU operating system. What most people think of as Linux really isn't (Linux is just the kernel). Most of what sits on top of it (the programs/tools and such) are from the GNU project or other independent projects. An OS using one of the new kernels being developed would look and feel just like Linux in terms of GUI/programs if it used the same tools/programs.

This [MP] is one thing makes the Mach kernel better than the Linux kernel. You might want to look into GNU/Hurd, but it is in the really early stages at this point. I'm not sure where the mkLinux project left off, but that too uses a Mach kernel which would probably give you good MP support.

Earth Mk. II · Jun 12, 2002, 12:34 PM

Mandrake has a SMP enabled 2.4 kernel for PPC. It should be on your distro CD's (or online).

Check your package manager. (search for 'kernel' or 'smp')

utidjian · Jun 15, 2002, 04:03 AM

<blockquote>quote:<hr />Originally posted by Northform:
I don't think that Linux will preform too well on an MP machine because of the design of its monolithic kernel which is unaware of threads and MP. Linux isn't really useful on MP hardware because it doesn't scale well. There are many projects going on right now to create better free kernels. These kernels could form the basis of a new GNU operating system.<hr /></blockquote>That is completely false. Linux does do threads... POSIX threads. It has supported threads and MP for years. I have been running it on 2way and 4 way systems for five years myself. Many applications and services that run on Linux based systems are multi-threaded. Apache-2.0 is one. I have even written code myself that takes advantage of threads/SMP myself.

<blockquote>quote:<hr /> What most people think of as Linux really isn't (Linux is just the kernel). Most of what sits on top of it (the programs/tools and such) are from the GNU project or other independent projects. An OS using one of the new kernels being developed would look and feel just like Linux in terms of GUI/programs if it used the same tools/programs.<hr /></blockquote>This is true.

<blockquote>quote:<hr />This [MP] is one thing makes the Mach kernel better than the Linux kernel. You might want to look into GNU/Hurd, but it is in the really early stages at this point. I'm not sure where the mkLinux project left off, but that too uses a Mach kernel which would probably give you good MP support.<hr /></blockquote>This might be true... do you have anything to back it up with?

-DU-...etc...

Northform · Jun 15, 2002, 09:16 AM

The Linux kernel is completely unaware of threads. The XWindows server and many of the upper level tools do support them, but that only goes so far. Just because an OS supports MP doesn't mean that it does it well (Mac OS 8 supports MP). It isn't the availability of the second processor that is key, but the ammount that the second processor gets used (will you see a 2% increase from the second processor...50%?). That's the important part why most Be users had MP machines.

If you read the debates on comp.os.minix between Andrew Tanenbaum and Linus Torvalds you will see what an advantage the Mach microkernel architecture is over the Linux monolithic architecture in terms of scaling to multiple processors (any you might loose all respect for the linux kernel in the process

). More seriously Linux was never designed to be used in the way that many people are now envisioning it being used. Linux is good at what it was designed for and it still competes reasonably against Windows in other segments simply because of the inadaquacy and outdated nature of Windows coupled with fervent free software developer support. I wish that the free software community would put more hours into development of the HURD kernel since it is vastly superior and changes can be made easier because of its object oriented nature instead of tring to extend an inferior yet adopted architecture.

I believe that the debates happened in 1992.

On a related note currently OS X doesn't have the best MP support, but that is not a fault of Apple's (at least not entirely). Many applications (carbon ones) do not support threading (yet) because the developer tried to get it out the door as quickly as possible. That doesn't mean that carbon doesn't support threading just that many devs haven't done some of the work yet. The Mach kernel is still able to work a little magic with these apps, but X can do much better with a little help from devs. All Cocoa apps are automaticly threaded properly.

utidjian · Jun 16, 2002, 09:14 PM

<blockquote>quote:<hr />Originally posted by Northform:
The Linux kernel is completely unaware of threads.<hr /></blockquote>How so? (please be specific) Are you using a different definition of threads?

The XWindows server and many of the upper level tools do support them, but that only goes so far.

How far is far enough? How much further should they go?

Just because an OS supports MP doesn't mean that it does it well (Mac OS 8 supports MP). It isn't the availability of the second processor that is key, but the ammount that the second processor gets used (will you see a 2% increase from the second processor...50%?). That's the important part why most Be users had MP machines.

Yes that may be relevant for Be users... but that OS is all but dead. I typically see speedups of 50-90% with dual CPUs on a Linux box with SMP kernel.

If you read the debates on comp.os.minix between Andrew Tanenbaum and Linus Torvalds you will see what an advantage the Mach microkernel architecture is over the Linux monolithic architecture in terms of scaling to multiple processors (any you might loose all respect for the linux kernel in the process

).

I have read that debate... several times. Where does it mention anything about Linux scaling to multiple CPUs 10 years ago?

More seriously Linux was never designed to be used in the way that many people are now envisioning it being used.

I would certainly agree that Linux is NOW being used in many ways that Linus did NOT "envision" at the time the LT/AT debates took place. Currently people are redesigning as much as they need to to get it work the way they want it to work. That is how it was designed. Whether they can make it work well in whatever role they "envision" is up to them.

Linux is good at what it was designed for and it still competes reasonably against Windows in other segments simply because of the inadaquacy and outdated nature of Windows coupled with fervent free software developer support. I wish that the free software community would put more hours into development of the HURD kernel since it is vastly superior and changes can be made easier because of its object oriented nature instead of tring to extend an inferior yet adopted architecture.

That remains to be seen. I would be very interested in a HURD system... perhaps we shall see it this summer. (Perhaps not).

I believe that the debates happened in 1992.

Yep... and I am supposed to take that as some authoritative statement on the way things are NOW?

On a related note currently OS X doesn't have the best MP support, but that is not a fault of Apple's (at least not entirely). Many applications (carbon ones) do not support threading (yet) because the developer tried to get it out the door as quickly as possible. That doesn't mean that carbon doesn't support threading just that many devs haven't done some of the work yet. The Mach kernel is still able to work a little magic with these apps, but X can do much better with a little help from devs.

(Shrug) Dissing Linux based on a debate made 10 years ago will not fix whatever problems OS X or its developers are having. There was a time, about 4-5 years ago, when Apple was quite interested in Linux. SJ tried to interest LT in what they were doing... LT wasn't interested.

All Cocoa apps are automaticly threaded properly.

Then why does performance suck so bad? I have heard a lot about the superiority of this, that and the other thing in Mac OS X... for over 2 years now... I have yet to see it work any better (usually a lot worse) than Linux does on the exact same hardware.

Perhaps you should read up on some more current information:

<a href="http://jungla.dit.upm.es/~jmseyas/linux/kernel/hackers-docs.html" target="_blank">http://jungla.dit.upm.es/~jmseyas/linux/kernel/hackers-docs.html</a>
(as a starting point)
<a href="http://www-106.ibm.com/developerworks/linux/library/l-rt7/?t=gr,Redhat=TheadsMgt" target="_blank">http://www-106.ibm.com/developerworks/linux/library/l-rt7/?t=gr,Redhat=TheadsMgt</a>
(for some specific examples)
<a href="http://www.scs.ch/~frey/linux/kernelthreads.html" target="_blank">http://www.scs.ch/~frey/linux/kernelthreads.html</a>
(for more details)
<a href="http://www.tldp.org/HOWTO/Parallel-Processing-HOWTO.html" target="_blank">http://www.tldp.org/HOWTO/Parallel-Processing-HOWTO.html</a>
(dated but still useful)
<a href="http://www.tldp.org/HOWTO/SMP-HOWTO.html" target="_blank">http://www.tldp.org/HOWTO/SMP-HOWTO.html</a>
(a little more recent)
<a href="http://www.tldp.org/FAQ/Threads-FAQ/index.html" target="_blank">http://www.tldp.org/FAQ/Threads-FAQ/index.html</a>
(just in case your questions have already been answered)