what SMP means?

dudulz · 03-02-2006, 07:22 PM

uname -a
linux-rs-1.dudulz.com 2.4.20 #SMP

what is SMP use for? I have read kernel book. There is Symetric Multi processing.

thanks

gilead · 03-02-2006, 07:47 PM

It stands for symmetric multi-processor. Do you have more than one CPU on your motherboard?

dudulz · 03-02-2006, 08:32 PM

i have implemented Linux Virtual Server (LVS) in my network. I have three computer in there.

lavluda · 03-02-2006, 08:32 PM

no need to processor on motherboard, if you have the HT , then it will works as two processor.

Check my signature

lavluda · 03-02-2006, 08:45 PM

Quote:

Originally Posted by dudulz

i have implemented Linux Virtual Server (LVS) in my network. I have three computer in there.

Ha great!!! how it's working. And what purpose you are using it?

dudulz · 03-02-2006, 08:59 PM

LVS is one of method load balancing. there is any scheduling to choose server in router. In router can schedules arrived packet and forward the choosen real server. But I confuse to understand what is SMP use for?

Electro · 03-02-2006, 09:39 PM

If each computer uses two or more processors or CPU, then it is a SMP. A kernel compile with SMP uses software techniques to run two or more programs at the same time without giving a portion of time to a program to run and then pause like is done on a single processor system.

In laymen terms, a kernel compile with SMP on a two processor system can run ut2004 and play a DVD with out any problems. A single processor system will be sluggish doing the same tasks.

sundialsvcs · 03-03-2006, 10:58 AM

When Linux "runs more than one program at a time," what it is actually doing is time-slicing. There's a clock in the machine that goes off several hundred times per second, and each time it does so (or sooner), Linux can switch from running one program to running another. When a program needs to wait, for any reason and for any length of time, the program "drops out of the run-list" until the condition that it's waiting for is satisfied.

A true multi-processor system (SMP) does the same thing for more than one hardware "engine" at a time. Each CPU is selecting runnable programs from the runlist and running them in time-sliced fashion.

If your CPU(s) have the hyperthreading{tm} feature, Linux will treat them as though each of them were "more than one CPU," because those CPUs have the ability to (to some degree) have more than one thread-of-execution active at the same time. Linux uses its SMP-support to handle this, as well.

To use multiple CPUs, your kernel must be compiled with SMP support enabled.