Bug#855116: linux-image-4.9.0-1-rt-amd64: error messages on boot about NOHZ and local_softirq_pending

[Laurent Bonnaud <L.Bonnaud@laposte.net>]

Package: src:linux
Version: 4.9.6-3
Severity: normal


Dear Maintainer,

I see the following error messages on 2 of my test systems:

# journalctl | grep NOHZ
Feb 13 14:12:25 irancy kernel: NOHZ: local_softirq_pending 100
Feb 13 14:12:25 irancy kernel: NOHZ: local_softirq_pending 100
Feb 13 14:12:27 irancy kernel: NOHZ: local_softirq_pending 02
Feb 13 14:12:34 irancy kernel: NOHZ: local_softirq_pending 02
Feb 13 14:12:34 irancy kernel: NOHZ: local_softirq_pending 02
Feb 13 14:12:34 irancy kernel: NOHZ: local_softirq_pending 02
Feb 13 14:12:34 irancy kernel: NOHZ: local_softirq_pending 02
Feb 13 14:12:36 irancy kernel: NOHZ: local_softirq_pending 02
Feb 13 14:12:36 irancy kernel: NOHZ: local_softirq_pending 02
Feb 13 14:12:36 irancy kernel: NOHZ: local_softirq_pending 02

# journalctl | grep NOHZ
févr. 14 10:44:37 jophur kernel: NOHZ: local_softirq_pending 02
févr. 14 10:44:38 jophur kernel: NOHZ: local_softirq_pending 02
févr. 14 10:44:40 jophur kernel: NOHZ: local_softirq_pending 02
févr. 14 10:44:40 jophur kernel: NOHZ: local_softirq_pending 02
févr. 14 10:44:50 jophur kernel: NOHZ: local_softirq_pending 02
févr. 14 10:44:50 jophur kernel: NOHZ: local_softirq_pending 02
févr. 14 10:44:50 jophur kernel: NOHZ: local_softirq_pending 02
févr. 14 10:44:50 jophur kernel: NOHZ: local_softirq_pending 02
févr. 14 10:44:50 jophur kernel: NOHZ: local_softirq_pending 02
févr. 14 10:44:50 jophur kernel: NOHZ: local_softirq_pending 02

I don't know if they are real errors, but they look like errors because they are displayed in red both by dmesg and journalctl.  They also appear on the screen even if the kernel is booted with the "quiet" option.  The non -rt kernel flavor does not output those messages.


-- Package-specific info:
** Version:
Linux version 4.9.0-1-rt-amd64 (debian-kernel@lists.debian.org) (gcc version 6.3.0 20170124 (Debian 6.3.0-5) ) #1 SMP PREEMP$

** Command line:
BOOT_IMAGE=/boot/vmlinuz-4.9.0-1-rt-amd64 root=UUID=cfd58a06-e091-4822-88c2-4b93329bb3d0 ro vsyscall=none security=apparmor $

** Not tainted

-- 
Laurent.