Home / ubuntu / Questions / 61957
Accepted
int_ua
Asked: 2011-09-19 07:16:59 +0800 CST

Do newer Ubuntu releases benefit from multicore processors at boot time?

  • 772

I've read the Upstart features and it says nothing about concurrency. I also read old advices to set CONCURRENCY value in the /etc/init.d/rc But there is a comment:

Specify method used to enable concurrent init.d scripts. Valid options are 'none', 'startpar' and 'makefile'. 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.

And the CONCURRENCY is set to none.

insserv is installed in my Ubuntu 11.04. But is it used?

My system is already amazingly fast because it's on the SSD. But I'd like to know if it uses all cores during boot.

boot

1 Answers

  1. Best Answer

    Increasingly this setting is becoming meaningless as most services are launched by Upstart. Only the scripts listed in /etc/init.d/ that are not symlinks are run as System V style init scripts.

    Chkconfig is not very useful on newer versions of Ubuntu (10.04 on) because so many of the jobs are now run by Upstart. Any error like the one you posted means bascially "this is an Upstart job, I can't do anything with it". The symlinks in /etc/init.d are for your convenience and for compatibility with scripts that expect to start services with a command like /etc/init.d/acpid start.

    The real startup script/job is /etc/init/acpid.conf. Only the scripts in /etc/init.d that aren't links to /etc/init can be manipulated with commands like chkconfig or update-rc.d.

    I don't expect there to be much speed difference at all with any setting you put in there. Upstart is already highly parallelized and it's doing by far most of the work booting your system. To answer the headline question: YES, the Ubuntu boot process is definitely taking advantage of multiple cores.

    • 8