[Novalug] Linux boot, was Re: Kernel Compiles
James Ewing Cottrell 3rd
JECottrell3@Comcast.NET
Sun Apr 18 11:11:36 EDT 2010
I dunno why nobody has mentioned this, but Process 0, at least on UNIX,
was initially the (kernel mode) Swapper Process. Process 1 is, of
course, (user mode) Init. BSD added (kernel mode) Process 2 as the
Pageout Daemon.
Now GNU/Linux is Not UNIX, but many of the same patterns remain. Perhaps
all those kernel threads are really just pieces of Process 0? That's
just details.
But the kernel really *is* "just another program", albeit a special
one, and its main execution path ends up as a (more maybe "some") Process.
To its descendents, it is like your parents, or maybe the government,
where you ask for things to be done.
Finally, to a Hypervisor, the kernel is "just another process", even if
they call it a Domain.
JIM
Bryan J. Smith wrote:
> Parent Process ID (PPID). Never tried a kill 0 myself, but feel free ... ;)
> I know a kill 1 will, on virtually every POSIX platform, bring down the
> system (how gracefully varies ;).
>
>
> When process names are in brackets ([]), it means the arguments are not known.
> This is often because the kernel executes the process, instead of a command shell.
>
> The kernel regularly forks or "wakes up" user processes to handle or monitor
> various operations when thresholds are reached. E.g., pdflush is one such
> process when various virtual memory (vm) thresholds are crossed.
>
>
>
>
> ----- Original Message ----
> From: Ed James <edward.james@gmail.com>
>
> This is where I get confused, because on my system init has PID 1 (and PPID 0).
>
> Question (for nobody in particular): for a "ps -ef", why are some of
> the process
> names in square brackets, like: [kthread] and [khelper]? Seems like most (not
> all) were forked/spawned/execed/birthed by init.
> _______________________________________________
> Novalug mailing list
> Novalug@calypso.tux.org
> http://calypso.tux.org/mailman/listinfo/novalug
>
>
> ------------------------------------------------------------------------
>
>
> No virus found in this incoming message.
> Checked by AVG - www.avg.com
> Version: 9.0.801 / Virus Database: 271.1.1/2811 - Release Date: 04/14/10 14:31:00
>
More information about the Novalug
mailing list