Full use of dual core processor

[fwc]

I found this article on boosting the potential for your dual core processor, but I was hoping someone could help explain exactly what the instructions are and whether it is very safe.
http://gizvillage.blogspot.com/2009/04/ ... se-of.html

Concurrent Booting: make full use of your dual-core, multithreaded or hyperthreaded processors in Ubuntu
This is a great way to make full use of your multi-core processors during boot time. I have an Intel core 2 duo processor and I have seen a notable change in boot time. Here's the how-to:

1. Enter the following command in a terminal window:

sudo gedit /etc/init.d/rc

Now look for CONCURRENCY=none and change it to CONCURRENCY=shell

2. But doing this might have some problems due to the dbus, hal and gdm race condition. For the multi-core processors to work properly, dbus should start first, hal the second and then gdm. This is not a problem in Hardy, Intrepid or Jaunty. For earlier versions, navigate to /etc/rc2.d/ folder by doing:

cd /etc/rc2.d/

Now do ls to list the files. Look for dbus, hal and gdm files. Mine has

s12dbus
s24hal
s30gdm

This means that dbus starts first, then the hal and then gdm. I you have something like this you don't have a problem. But if you have something similar to

s12dbus
s13gdm
s24hal

you need to do the following to fix this issue:

mv s24hal s13hal
mv s13gdm s14gdm

This will reorder the start processes and now CONCURRENCY=shell option can be used. For more information about the dbus, hal and gdm race condition, see this page. Please write in the comments if you have any questions.

[atlef]

I use the CONCURRENCY=shell thing and it works just great, shaves a few seconds off the time it takes to boot my machine.
Can not explain it though.

atlef.

[Aging Technogeek]

Saw this post earlier today and had to try it. I'm running an Intel Q6600 Core 2 quad. It installed easy and makes a noticeable difference in boot and run speed.

Got to put it in my laptop too (Core 2 duo T7700).

To fwc - Go for it . Just be sure you check the dbus, hal ,and gdm files for proper start up sequence as it explains in the article.

Open terminal and enter (or copy and paste)

Code: Select all

$ sudo gedit /etc/init.d/rc

Enter your password when asked.A window should open and show you a script.

Code: Select all

#! /bin/sh
#
# rc
#
# Starts/stops services on runlevel changes.
#
# Optimization: A start script is not run when the service was already
# configured to run in the previous runlevel.  A stop script is not run
# when the the service was already configured not to run in the previous
# runlevel.
#
# Authors:
# 	Miquel van Smoorenburg <miquels@cistron.nl>
# 	Bruce Perens <Bruce@Pixar.com>

PATH=/sbin:/usr/sbin:/bin:/usr/bin
export PATH

# Un-comment the following for debugging.
# debug=echo

# Specify method used to enable concurrent init.d scripts.
# Valid options are 'none', 'shell' and 'startpar'.  To enable the
# concurrent boot option, the init.d script order must allow for
# concurrency.  This is not the case with the default boot sequence in
# Debian as of 2008-01-20.  Before enabling concurrency, one need to
# check the sequence values of all boot scripts, and make sure only
# scripts that can be started in parallel have the same sequence
# number, and that a scripts dependencies have a earlier sequence
# number. See the insserv package for a away to reorder the boot
# automatically to allow this.
CONCURRENCY=none

There is a lot more but the part we need is the line that says "CONCURRENCY= none". Just change "none" to "shell" , save the changes and close the window.

[fwc]

Ok, thanks guys. But I wonder why this isn't done by default if its so beneficial..

[AK Dave]

Ok, thanks guys. But I wonder why this isn't done by default if its so beneficial..

1. Not everyone had dual-core or hyper-threaded cpus, thus not everyone can benefit from this.
2. There are conditions where even with dual-core this can cause problems, specifically as regards encrypted partitions.
3. Linux boxes need to reboot so infrequently that shaving a few seconds off of what should be a rare task is low priority.
4. Standards are based on lowest common denominators.
5. Us power user geeks need to have some little tweak we can do to make ourselves feel a little smug and superior.

[Aging Technogeek]

AK Dave

+1

Especially item 5!