[DC LoCo] Linux, multiple cpus and memory use

[Ben Gamari]

On Thu, 22 Sep 2011 11:35:26 -0400, Dan Barry <mr.danbarry at gmail.com> wrote:
> The computers I use presently are netbooks using a celeron and 2nd
> generation atom. Both are hardware limited to 2 gigs of memory and use 8 gig
> SD and 160 gig HD respectively.  The atom ,a Samsung, boots between linux(
> linux Mint and ubuntu original) and XP ( so I can run the Zune software for
> my windows phone), and too other defunk partitions I have not wiped out.
>      My dual processor system was set up in Germany and used a cheap 230-40
> power supply so I left it there. Its time to build another desktop.
> 
> 1. Does the linux kernel use memory as a pool for the processors it finds in
> hardware?
>     Or does it seperate the memory allowing some just some for each
> processor?
> 
To first order, memory is pooled between all processors. That being
said, most modern processors have a non-uniform memory architecture
(e.g. some memory regions are "closer" to some processors than
others). The kernel accounts for the memory topology during allocation
to maximize data locality.

> 2. I would like to do some network training with VM partitions to seperate
> server and client and wondered what configurations VM prefers?
>     Does this vary when I try to VM with an XP partition.
> 
Not entirely sure I understand the question. Look into KVM. This is the
kernel's default virtualization framework.

> 3. Is there a Linux build particularly adapted to multiple processors?
> 
Most any distribution should ship with an SMP kernel by default on the
x86 architecture. With multicore processors being the norm now, single
processor machines are becoming increasingly rare.

Really, there's no reason to worry about things like (1) and (3). Linux
is an industrial strength operating system. It is quite well adapted to
run on any hardware you can throw at it; from 4000-core supercomputers
to a small ARM.

Cheers,

- Ben