Re: [LONG] Re: runit not collecting zombies

[Alex Efros <powerman@powerman.name>]

Hi!

On Tue, Feb 15, 2011 at 02:12:18PM +0100, Laurent Bercot wrote:
>  runit ran perfectly without polling for lots of people except Radek and
> Alex. Until Gerrit had to add a polling mechanism just for them.

AFAIR this polling mechanism doesn't solved issue for me, but I may be
wrong because that was long time ago. Anyway, I'm still using `kill -CONT 1`
hack in /etc/cron.hourly/ to work around this issue on all my systems.

>  I ran the following command while stracing my own process 1 (s4-svscan,
> which does not poll) on a Linux 2.6.36.1 kernel:

Again, this was long time ago and I may be wrong, but AFAIR this simple
trick with two processes wasn't correct example to reproduce this issue.

>  The problem Radek and Alex had was most likely caused by a kernel bug:
> in some cases, when a zombie is reparented to process 1, process 1 does
> not get notified with a SIGCHLD, as it should be.

Ok, there no harm to trying. I repeated your test with strace - on my
current system runit got SIGCHLD. I'm using kernel 2.6.36-hardened-r9 and
runit 2.0.0. I've just switched off hourly `kill -CONT 1` workaround, so
we'll see is everything fine in a couple of days.

If there will be no growing army of zombies on my system after that, I'll
be glad to test modified runit version without polling if someone send me
the patch.

-- 
			WBR, Alex.