Re: mmotm 2009-08-24-16-24 uploaded

From: Oleg Nesterov
Date: Thu Aug 27 2009 - 06:56:25 EST


On 08/27, KAMEZAWA Hiroyuki wrote:
>
> On Thu, 27 Aug 2009 12:08:46 +0200
> Oleg Nesterov <oleg@xxxxxxxxxx> wrote:
>
> >
> > OK, I seem to understand what happens. Could you try the patch below?
> >
>
> worked.

Thanks. I need to think a bit, then I send the fix.

> IMHO, it's necessary to "wake up parent with -ECHILD if all children dies"

Of course! It was supposed to do. More precisely, we should wake up when
any child which cuould be interesting to ->parent dies. No need to check
"all children died" case specially. If parent sleeps on ->wait_chldexit
there must be at least on eligible child.

The problem is, do_notify_parent() changes ->exit_signal _before_ it calls
__wake_up_parent(). This changes the result of eligible_child().

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/