Re: + kmod-avoid-deadlock-by-recursive-kmod-call.patch added to-mm tree

From: Oleg Nesterov
Date: Sun Jan 29 2012 - 11:38:01 EST


On 01/29, Rusty Russell wrote:
>
> On Fri, 27 Jan 2012 15:32:34 +0100, Oleg Nesterov <oleg@xxxxxxxxxx> wrote:
> > On 01/27, Rusty Russell wrote:
> > > On Thu, 26 Jan 2012 18:56:12 +0100, Oleg Nesterov <oleg@xxxxxxxxxx> wrote:
> > > > Can't we simply kill khelper_wq and use system_unbound_wq instead?
> > >
> > > I'd prefer that, because then we'd hit the existing "too many modprobes"
> > > check.
> >
> > Hmm. Why? I mean, why do you think that s/khelper_wq/system_unbound_wq/
> > leads to recursive __request_module's ?
> >
> > Note that that this patch (which adds kmod_thread_locker) can not limit
> > the recursive modprobe loop.
> >
> >
> > OK, yes, with system_unbound_wq we can hit this warning if we have
> > max_modprobes UMH_WAIT_EXEC's resulting in __request_module at the
> > same time, but probably this is good?
>
> Yes, that's what I'm saying.
>
> We already have a check against too many modprobes, it might be best to
> use it.

Confused... in this case I do not understand why do you dislike the
idea to kill khelper_wq.

Help!

Oleg.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/