Puppy Linux Discussion Forum

[tempestuous]

There has been much talk about "SMP" lately, and there are now several Puppy derivatives available with this feature.
"SMP" (symmetric multi processing) support allows the use of more than one processor, and this is the most basic form of multi-processor support in the Linux kernel.

"Hyperthreading" is a simplified form of multi-processing within a single CPU, introduced with late model Pentium 4's.

"Multi-core" support is for recent processors which have independent processing cores within a single CPU.

All three forms of multi-processor support can be enabled within the Linux kernel, and I know that MU and wow enabled all three in the kernel for "Unnamed pupplet (puppy411 kernel-2.6.27.5 Xorg-7.4 LXDE)"
http://www.murga-linux.com/puppy/viewtopic.php?t=36592

So how does this sit with older, non-SMP capable computers?
I experimented with cutting-edge kernels as far back as July 2007 -
http://www.murga-linux.com/puppy/viewtopic.php?t=19719
and I found that this SMP kernel booted just fine on my old Pentium2-350 ...

but I know that many people are not so lucky, and SMP kernels can fail to boot on older computers.
But the fix should be easy - just disable the SMP features with boot options. To disable SMP, hyperthreading, and multicore support at boot time, use these boot options -

[Lobster]

Thanks for info, very interesting.
Puppy Linux Schooling strikes again

Is there a hardware test at this stage that could bypass the need to ask if a multiprocessor is being used?

[ttuuxxx]

Sounds like we almost need a new popup screen asking if we want smp or not during bootup.
ttuuxxx

[technosaurus]

it would be pretty easy to have multiple (descriptive) menu entries via isolinux.cfg and menu.lst ... people with older computers can simply press the down arrow and enter

[fzsolt]

Hi! I own a computer with an old Abit BH6 (world's one and only mobo designed specifically for dual celeron usage ) with a pair of celeron (Mendocino) 533 MHz CPUs installed (512 MB RAM, Matrox G200 video card). Puppies from 1.x to 3.x run fine, although I never tried SMP kernels.
I experimented on this machine since Barry started to implement multiprocessor support in alpha 4 puppies. After many boot failures I noticed that if I disconnect the HDD, they boot. SMP worked. So I concluded that the problem may be the onboard HPT 366 ATA 66 controller.
Little different with final 4.xx Puppies. Retro versions boot with HDD connected, although no harddisks are seen in drive mounter, and of course, no SMP. Non-retro 4.xx versions don't boot. Same for new SMP enabled puppies (NewYears, Lighthouse, aragon's SMP, Slaxter, etc.), simply don't work. After the "booting the kernel" message I end up with a completely blank screen (even if HDD disconnected).
Is there a ready-made (iso) of SMP enabled version 2 or version 3 Puppy somewhere? Or is there a decription somewhere how can I compile a kernel with SMP (but not HyperT, nor multicore) support (and support for HPT 366 too)?

[clarf]

[DaveS]

So what happens when using normal nosmp kernels on dual core processors? Are we only using half the processing power available, or can the kernel somehow use it all?
FYI, on my dual-core laptop, standard 4.2 needs the status bar turned off in Pmusic to play evenly, but on 4.2 SMP, its fine, so something is working better.

[steevieb]

clarf
The first Puppy 4 series with SMP was Puppy4 Alpha5
Uname -a shows
Linux puppypc 2.6.25.11 #1 SMP Sun Jul 20 22:58:10 GMT-8 2008 i686 GNU/Linux

There may be retro versions using earlier kernels, IDK.

fzsolt
I used to have a mobo with that controller, and I think it shows itself as a SCSI controller.
Are your drives IDE, SCSI or RAID?
You may need a different vmlinuz so that the Highpoint is recognised.
See here and here
If you need a copy of SCSI-1,2 or3, I may be able to upload a copy somewhere. Ted Dog's site is down.

[fzsolt]

steevieb,

Thank you for your reply. Yes, I noticed that the HPT366 appears in the windows device manager as a SCSI device. But I don't know how is it treated in linux.
There is one IDE HDD (15G Quantum lct something) connected to the HPT366 now, no RAID (the CD drive is connected to the normal IDE connector, so it works and Puppy boots from there).
I will try SCSI puppy. I have an old server case with an Asus P2B-DS board and some SCSI HDDs and optical drives in the drawer, so I am going to try to build a full SCSI Puppy machine.
Why do you still use Dingo 4 alpha5? Is SCSI support dropped from newer 4xx?

[steevieb]

[clarf]

[tempestuous]

[fzsolt]

steevieb, tempestuous,

Thank you for your detailed answers.
Yes, BH6 is my mistake, the board with two celerons is a BP6 (I had a BH6 before that).
Yesterday I experimented a little, and realized that the other problem in that machine is the Matrox (marvel G200) graphics card. After replacing it for a GeF MX440 and disconnecting the HDD from the HPT366, new 4xx based Puppies booted and worked. I tried 4.1, Tipsy 4.1.3 with universal video drivers and Lighthouse 4.1.2 RC3, all worked and I had SMP in Lighthouse (I had no other SMP version boot CD at hand).
I was rather surprised. What problem the kernel may have with a graphics card during booting, when everything goes in text mode?
When plugged in the HDD, boot failed again. So there can be problems with the HDD, I will try with a different one.
I will try other SMP puppies too, with a different video card and HDD. I think I will open a thread for this mobo in the Hardware section and post my findings there.