Arch Linux

Jacek Poplawski

Member

From: Poland

Registered: 2006-01-10

Posts: 736

Website

nosmp

I want to disable SMP in my Arch.
I tried option "nosmp" at boot time, but it leads to problems with disk (lost interrupt).
Is there any other way than kernel recompilation?

iphitus

Forum Fellow

From: Melbourne, Australia

Registered: 2004-10-09

Posts: 4,927

Re: nosmp

Why do you need to disable it?

for drivers? If so, then a recompilation is your only option

James

AndyRTR

Developer

From: Magdeburg/Germany

Registered: 2005-10-07

Posts: 1,641

Re: nosmp

... but it leads to problems with disk (lost interrupt)...

Have you tried the "noapic" option?

Jacek Poplawski

Member

From: Poland

Registered: 2006-01-10

Posts: 736

Website

Re: nosmp

Why do you need to disable it?

I am a developer and I need to test my application - it segfaults sometimes on system with SMP, I need to perform tests without SMP and same setup. I wonder why "nosmp" doesn't work correctly.

the incredible hurd

Member

Registered: 2007-01-01

Posts: 2

Re: nosmp

Why do you need to disable it?

Severe performance penalty on uniprocessor systems with SMP enabled kernels would be a good reason too.

I have the same issue if I add the nosmp parameter on my desktop/workstation:

hda: lost interrupt

I wonder why not on hdb.

But on my laptop nosmp works like a charm.

It seems a kernel bug, doesn't it?

iphitus

Forum Fellow

From: Melbourne, Australia

Registered: 2004-10-09

Posts: 4,927

Re: nosmp

the performance penalty is hardly severe, it's negligable.

as for nosmp, it still isnt a true uniproc kernel. If you want a proper single proc kernel you must compile it with SMP disabled. Testing under nosmp is not a reliable method.

James