Re: init's children list is long and slows reaping children.

Andrew Morton
2007-04-10T08:41:31Z

On Tue, 10 Apr 2007 04:33:57 -0400 Jeff Garzik <jeff@garzik.org> wrote:

> Andrew Morton wrote:
> > On Tue, 10 Apr 2007 03:05:56 -0400 Jeff Garzik <jeff@garzik.org> wrote:
> >
> >> My main
> >> worry with keventd is that we might get stuck behind an unrelated
> >> process for an undefined length of time.
> >
> > I don't think it has ever been demonstrated that keventd latency is
> > excessive, or a problem. I guess we could instrument it and fix stuff
> > easily enough.
>
> It's simple math, combined with user expectations.
>
> On a 1-CPU or 2-CPU box, if you have three or more tasks, all of which
> are doing hardware reset tasks that could take 30-60 seconds (realistic
> for libata, SCSI and network drivers, at least), then OBVIOUSLY you have
> other tasks blocked for that length of time.

Well that obviously would be a dumb way to use keventd. One would need
to do schedule_work(), kick off the reset then do schedule_delayed_work()
to wait (or poll) for its termination.