Re: (forw) Linux + SMP

[William T Wilson <fluffy@snurgle.org>]

On Thu, 16 Dec 1999, Paulo Henrique Baptista de Oliveira wrote:

> 	I posted a message to linux-kernel to help me in a small paper
> that I have to do for tomorrow and dont see an answer. It is a few
> related questions about Linux + SMP. If there is a Linux kernel guru
> in this list that can answer my questions I will thanks a lot.

They're busy - I'm not surprised they didn't answer.

>       1) When Linux kernel begins to support SMP (what version)? and
> How many processors and types of machines it supported in the
> beggining?

SMP support started sometime in the 1.3 series (1.3.3x?).  Of course it
didn't work very well until late in 1.3 (I think 1.3.8x?).  At first, it
only supported x86 processors.  Although it's always supported many
processors (I think never fewer than 16) until 2.2 there wasn't very much
benefit to more than about 4 since the lock system wasn't very good.

>       2) What support Linux 2.2.* (stable versions) provides about SMP?

SMP is much faster now and scales better.  It supports Alpha now too -
more or less, and Sparc too.

>       3) What are the main routines and functions in Linux 2.2.* that provide
> support for SMP?

Can't help you there.

But Linus makes lots of documentation on the changes.  Go to
http://www.linuxhq.com/changes/2.3.html and
http://www.linuxhq.com/kernel2.2/wonderful.html
for lots of fun information.  You'll have to do some wading through
documentation because it includes *all* the changes - not just SMP.