Pqluglist- Rethinking PID 1

[Parksville-Qualicum Linux Users group mail list]

If you are really geeky you might enjoy this.

  http://0pointer.de/blog/projects/systemd.html

"Process Identifier 1

On every Unix system there is one process with the special process identifier 1. 
It is started by the kernel before all other processes and is the parent process 
for all those other processes that have nobody else to be child of. Due to that 
it can do a lot of stuff that other processes cannot do. And it is also 
responsible for some things that other processes are not responsible for, such 
as bringing up and maintaining userspace during boot.

Historically on Linux the software acting as PID 1 was the venerable sysvinit 
package, though it had been showing its age for quite a while. Many replacements 
have been suggested, only one of them really took off: Upstart, which has by now 
found its way into all major distributions.

As mentioned, the central responsibility of an init system is to bring up 
userspace. And a good init system does that fast. Unfortunately, the traditional 
SysV init system was not particularly fast.

For a fast and efficient boot-up two things are crucial:

     * To start less.
     * And to start more in parallel.
"

-- 

Alfred