Re: is reparent_to_init a good thing to do?

[Andrew Morton <akpm@zip.com.au>]

BALBIR SINGH wrote:
> 
> I was looking at the driver under drivers/net/8139too.c, a kernel
> thread rtl8139_thread is created, it calls daemonize() and soon
> afterwards calls reparent_to_init(). Looking at reparent_to_init(),
> it looks like all kernel threads should do this. But, I feel I am missing
> something, since not everybody does this.
> 
> Is this a good thing to do? or are there special cases when we need this.
> 

I think yes, more kernel threads need to use this function.  Most
particularly, threads which are parented by a userspace application
and which can terminate.  For example, the nfsd threads.

Right now, it's probably the case that nfsd threads will turn
into zombies when they terminate, *if* their parent is still
running.   But of course, most kernel threads are parented
by very short-lived userspace applications, so nobody has
ever noticed.