[systemd-devel] [lennart at kemper.freedesktop.org: [systemd-commits] src/pam-module.c]

[Lennart Poettering]

On Tue, 08.02.11 14:52, Andrey Borzenkov (arvidjaar at mail.ru) wrote:

> >> I speak about failure of rtkit-daemon to put itself in RT scheduling
> >> group on startup. At this point there is no login at all.
> >>
> >> Anyway, I rebuild systemd with your PAM patch and restarted system and
> >> as expected nothing changed:
> >>
> >> Feb  8 14:14:51 cooker rtkit-daemon[3165]: Failed to make ourselves
> >> RT: Operation not permitted
> >
> > Hmpf. so you are suggesting that although rtkit itself is in the cpu:/
> 
> No. I do not. You stated it :)
> 
> As indicated by ps output, rtkit-daemon is *not* in cpu group
> 
> {pts/1}% ps xawf -eo pid,args,cgroup | grep rtkit
>  3165 /usr/lib64/rtkit-daemon     name=systemd:/system/rtkit-daemon.service
> 
> Compare this with any other service like
> 
> {pts/1}% ps xawf -eo pid,args,cgroup | grep networkmanager
>  1277 /usr/sbin/NetworkManager --
> cpu:/system/networkmanager.service;name=systemd:/system/networkmanager.service
>  2550  \_ /sbin/dhclient -d -4 -s
>
>  cpu:/system/networkmanager.service;name=systemd:/system/networkmanager.service
> 
> BTW rtkit is the only service having ControlGroup at all ...

Well, yes. ps supresses the output if a process is in the root group of
a hierarchy, because by default all processes are in the default
group. To get the full list of cgorup memberships you could look into
/proc/$(pidof rtkit-daemon)/cgroup. 

> > cgroup it cannot make itself RT? That is really weird. What is the
> > contents of /sys/fs/cgroup/cpu/cpu.rt_*_us?
> >
> 
> {pts/1}% cat /sys/fs/cgroup/cpu/cpu.rt_*_us
> 1000000
> 950000

Weird, weird, weird. So, systemd is in the right cgroup with correct
settings but still doesn't have the privs to make itself RT. There's
something very weird here.

Lennart

-- 
Lennart Poettering - Red Hat, Inc.