[systemd-devel] Query on libpam-systemd

[Mantas Mikulėnas]

On Fri, Jan 29, 2016 at 8:08 AM, pavi1729 <pavitra1729 at gmail.com> wrote:

> Hi,
>   I have an issue with libpam-systemd which is interfering with
> scheduler settings on my machine. Details as below
>
> --------------------------------------------------------------------------
> File: linux/kernel/sched/core.c
>
> WITHOUT libpam-systemd
>
> [   36.278241] rt_bandwidth_enabled(): 1
> [   36.281977] rt_policy(policy) : 1
> [   36.285367] task_group_is_autogroup(task_group(p)) : 0
> [   36.289883] task_group(p)->rt_bandwidth.rt_runtime : 950000000
>
>
> WITH libpam-systemd INSTALLED
>
> [ 2096.713855] rt_bandwidth_enabled(): 1
> [ 2096.717871] rt_policy(policy) : 1
> [ 2096.721408] task_group_is_autogroup(task_group(p)) : 0
> [ 2096.726180] task_group(p)->rt_bandwidth.rt_runtime: 0  <-- (gets set to
> 0)
>
>
> QUESTION: Why is libpam-systemd setting
> task_group(p)->rt_bandwidth.rt_runtime to 0 ?
>

Probably due to moving the process to a separate (per-user) cgroup; check
/proc/self/cgroup.

There are known kernel problems with RT scheduling; see also:
https://github.com/systemd/systemd/blob/master/README#L99-L106


> SYSTEM DETAILS
>
> root at pavi:/home/pavi# uname -a
> Linux pavi 3.18.21-pavi-g4c8a53e-dirty #43 SMP PREEMPT Fri Dec 18
> 14:56:40 IST 2015 aarch64 aarch64 aarch64 GNU/Linux
>
>
> root at pavi:/home/pavi# cat /etc/os-release
> NAME="Ubuntu"
> VERSION="15.04 (Vivid Vervet)"
> ID=ubuntu
> ID_LIKE=debian
> PRETTY_NAME="Ubuntu 15.04"
> VERSION_ID="15.04"
> HOME_URL="http://www.ubuntu.com/"
> SUPPORT_URL="http://help.ubuntu.com/"
> BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/"
>

But which systemd version?

-- 
Mantas Mikulėnas <grawity at gmail.com>
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