Re: [PATCH] call_usermodehelper needs to wait longer

From: Rusty Russell
Date: Wed Mar 10 2004 - 05:50:43 EST

On Wed, 2004-03-10 at 19:24, Srivatsa Vaddagiri wrote:
> On Tue, Mar 09, 2004 at 01:38:35PM -0800, Andrew Morton wrote:
> > I'm not so sure about this. There are deadlock potentials if the usermode
> > application wants to perform some function which requires keventd services
> > to complete - the application cannot complete because keventd is itself
> > waiting for the application.
> >
> > Can we think of any circumstances under which keventd _should_
> > synchronously wait for the userspace app?
> Honestly I don't know ..Would it be reasonable for somebody
> to call request_module from a work function (in which case the above
> bug is exposed)? I agree it is not a nice thing if we block keventd
> waiting for the app to exit.

I think a BUG_ON(wait) is arguably right here: anyone trying it will hit
it immediately. Perhaps a "/* keventd shouldn't block */" comment above
it would help.

Anyone who quotes me in their signature is an idiot -- Rusty Russell

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at