[LTP] [PATCH] memcg/functional: check several times if the process is killed

[Jan Stancek <jstancek@redhat.com>]

----- Original Message -----
> From: "Cyril Hrubis" <chrubis@suse.cz>
> To: "Stanislav Kholmanskikh" <stanislav.kholmanskikh@oracle.com>
> Cc: "Jan Stancek" <jstancek@redhat.com>, "vasily isaenko" <vasily.isaenko@oracle.com>, ltp@lists.linux.it
> Sent: Tuesday, 24 May, 2016 12:15:28 PM
> Subject: Re: [LTP] [PATCH] memcg/functional: check several times if the process is killed
> 
> Hi!
> > > We should better change this for something more robust. Given that the
> > > memgc_progcess does while (!flag_exit) sleep(1); in the main loop we may
> > > as well wait till the process gets into the sleep state.
> > >
> > 
> > I don't understand why it's more robust. For example, a process can get
> > into the sleep state (interruptible sleep) due to a call to a syscall, no?
> 
> Generally yes, but in this case it's unlikely that opening /dev/zero or
> calling sigaction() would block.

There's also some ld setup going on before that. Opening/mapping/reading
various config and .so files.

> 
> > So maybe keep this sleep() as is?
> 
> I'm Ok with that one as well. But we should rethink and fix it later.

My immediate idea was to let memcg_process open "/tmp/memcg_process_ready"
and shell script would monitor /proc/$pid/fd/ until sees that or hits timeout.

Regards,
Jan