Re: [patch] sched: get rid of p->children use in show_task()

Ingo Molnar
2007-04-06T19:23:17Z

* Ingo Molnar <mingo@elte.hu> wrote:

> > > i.e. a to-be-reaped task will still be on the main list _too_. The
> > > main list is for all the PID semantics rules. The reap-list is
> > > just for wait4() processing. The two would be completely separate.
> >
> > And what pray tell except for heuristics is the list of children
> > used for?
>
> yeah - by all means get rid of it, but first separate the data
> structures along uses. Then all the 'why should we iterate two lists
> in sequence' questions vanish.

and this way we get the best change as well: not only will kthreads be
removed from that list, but all other tasks in the system too. I bet
this will speed up wait4() _enormously_, on server workloads that
involve many tasks.

Ingo