Red Hat Bugzilla – Bug 1252156
ERROR writing to file /sys/devices/system/cpu/intel_pstate/no_turbo: Operation not permitted
Last modified: 2016-11-04 03:24:10 EDT
Created attachment 1061237 [details]
Description of problem:
The following error appears in /var/log/tuned/tuned.log:
2015-08-10 15:04:11,997 ERROR tuned.utils.commands: Writing to file /sys/devices/system/cpu/intel_pstate/no_turbo error: [Errno 1] Operation not permitted
Version-Release number of selected component (if applicable):
# yum list installed | egrep tuned
tuned.noarch 2.5.1-1.el7 @beaker-Server/7.2
tuned-profiles-nfv.noarch 2.5.1-1.el7 @/tuned-profiles-nfv-2.5.1-1.el7.noarch
tuned-profiles-realtime.noarch 2.5.1-1.el7 @beaker-Server-RT
Unknown, but it has appeared multiple times
Steps to Reproduce:
1. Install tuned-profiles-realtime # this might be enough
2. tuned-adm profile virtual-host
ERROR in logfile
# uname -a
Linux localhost.localdomain 3.10.0-302.rt56.174.el7.x86_64 #1 SMP PREEMPT RT Mon Aug 3 15:01:33 EDT 2015 x86_64 x86_64 x86_64 GNU/Linux
# cat /proc/cmdline
BOOT_IMAGE=/vmlinuz-3.10.0-302.rt56.174.el7.x86_64 root=/dev/mapper/rhel_virtlab420-root ro crashkernel=auto rd.lvm.lv=rhel_virtlab420/root rd.lvm.lv=rhel_virtlab420/swap console=ttyS1,115200 default_hugepagesz=1G isolcpus=1,3,5,7,9,11,13,14,15 nohz_full=1,3,5,7,9,11,13,14,15 intel_pstate=disable nosoftlockup
# lscpu | grep NUMA
NUMA node(s): 2
NUMA node0 CPU(s): 0,2,4,6,8,10,12,14
NUMA node1 CPU(s): 1,3,5,7,9,11,13,15
There is intel_pstate check in tuned, thus it shouldn't touch no_turbo if intel_pstate driver isn't loaded. It checks presence of '/sys/devices/system/cpu/intel_pstate' directory. I verified that the directory isn't there if machine is booted with 'intel_pstate=disable', thus Tuned shouldn't touch no_turbo in this case. So it seems intel_pstate driver is active on the machine and the machine hasn't turbo/no_turbo.
Nevertheless, if no_turbo isn't specified in the profile and there is intel_pstate driver, Tuned needn't to save no_turbo state. This could be improved.
(In reply to Jaroslav Škarvada from comment #3)
> Nevertheless, if no_turbo isn't specified in the profile and there is
> intel_pstate driver, Tuned needn't to save no_turbo state. This could be
Fixed by upstream commit:
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.