Bug 1367502

Summary: tuned realtime profiles need rcu_nocbs
Product: Red Hat Enterprise Linux 7 Reporter: Marcel Kolaja <mkolaja>
Component: tunedAssignee: Jaroslav Škarvada <jskarvad>
Status: CLOSED ERRATA QA Contact: Tereza Cerna <tcerna>
Severity: urgent Docs Contact:
Priority: urgent    
Version: 7.2CC: atheurer, daolivei, hhuang, jeder, jscotka, jskarvad, juzhang, ksundara, lcapitulino, mnavrati, pezhang, sgordon, skramaja, smazziot, snagar, tcerna, thozza, xfu
Target Milestone: rcKeywords: ZStream
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: tuned-2.5.1-4.el7_2.5 Doc Type: Bug Fix
Doc Text:
Previously, with the realtime-virtual-host and realtime-virtual-guest tuned profiles, the rcu_nocbs kernel parameter was missing from the /proc/cmdline file. With this update, rcu-nocbs is included as expected.
Story Points: ---
Clone Of: 1334479 Environment:
Last Closed: 2016-09-15 08:00:34 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 1334479    
Bug Blocks:    

Description Marcel Kolaja 2016-08-16 14:34:28 UTC
This bug has been copied from bug #1334479 and has been proposed
to be backported to 7.2 z-stream (EUS).

Comment 4 Tereza Cerna 2016-08-23 08:48:41 UTC
=============================================
Verified in:
    tuned-2.5.1-4.el7_2.5.noarch
    tuned-profiles-nfv-2.5.1-4.el7_2.5.noarch
PASS
=============================================

# cat /usr/lib/tuned/realtime-virtual-host/tuned.conf | grep cmdline
cmdline=isolcpus=${isolated_cores} nohz=on nohz_full=${isolated_cores} rcu_nocbs=${isolated_cores} intel_pstate=disable nosoftlockup
# cat /etc/tuned/realtime-virtual-host-variables.conf
isolated_cores=1
# tuned-adm profile realtime-virtual-host
# reboot
# cat /proc/cmdline 
BOOT_IMAGE=/vmlinuz-3.10.0-493.el7.x86_64 root=/dev/mapper/rhel_dell--pe--fm120--2c-root ro crashkernel=auto rd.lvm.lv=rhel_dell-pe-fm120-2c/root rd.lvm.lv=rhel_dell-pe-fm120-2c/swap console=ttyS0,115200n81 isolcpus=1 nohz=on nohz_full=1 rcu_nocbs=1 intel_pstate=disable nosoftlockup

The same behavior is also for realtime-virtual-guest.

=============================================
Reproduced in:
    tuned-2.5.1-7.el7.noarch
    tuned-profiles-nfv-2.5.1-7.el7.noarch
FAIL
=============================================

# cat /usr/lib/tuned/realtime-virtual-host/tuned.conf | grep cmdline
cmdline=isolcpus=${isolated_cores} nohz=on nohz_full=${isolated_cores} intel_pstate=disable nosoftlockup
# cat /etc/tuned/realtime-virtual-host-variables.conf
isolated_cores=1
# tuned-adm profile realtime-virtual-host
# reboot
# cat /proc/cmdline 
# cat /proc/cmdline 
BOOT_IMAGE=/vmlinuz-3.10.0-493.el7.x86_64 root=/dev/mapper/rhel_dell--pe--fm120--2c-root ro crashkernel=auto rd.lvm.lv=rhel_dell-pe-fm120-2c/root rd.lvm.lv=rhel_dell-pe-fm120-2c/swap console=ttyS0,115200n81 isolcpus=1 nohz=on nohz_full=1 intel_pstate=disable nosoftlockup

Comment 6 errata-xmlrpc 2016-09-15 08:00:34 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHBA-2016-1848.html