Bug 1329101 - kernel 4.4.7-300.fc23.x86_64 uses more cpu than 4.4.6-301.fc23.x86_64
Summary: kernel 4.4.7-300.fc23.x86_64 uses more cpu than 4.4.6-301.fc23.x86_64
Keywords:
Status: CLOSED INSUFFICIENT_DATA
Alias: None
Product: Fedora
Classification: Fedora
Component: kernel
Version: 23
Hardware: x86_64
OS: Linux
unspecified
medium
Target Milestone: ---
Assignee: Kernel Maintainer List
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2016-04-21 08:22 UTC by William Bader
Modified: 2019-11-19 16:45 UTC (History)
7 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed: 2016-10-26 16:53:39 UTC
Type: Bug
Embargoed:


Attachments (Terms of Use)

Description William Bader 2016-04-21 08:22:36 UTC
Description of problem:

After updating to 4.4.7-300.fc23.x86_64, I noticed that the fan on my laptop never goes off. gkrellm shows that even with the system idle, the cpu is 59 C, while if I reboot with 4.4.6-301.fc23.x86_64, the cpu is 54 C.

"top" does not show anything getting more than a fraction of a percent of the cpu.

I have a Sony Vaio laptop with an Intel(R) Core(TM) i5-2450M CPU @ 2.50GHz, 8 GB RAM, a 512 GB SSD, with Fedora 23 and the Mate desktop.

The only hardware ports in use are a USB port for the mouse and the wired ethernet port.

Version-Release number of selected component (if applicable):

kernel-4.4.7-300.fc23.x86_64

How reproducible:

It seems to happen every time. I tried restarting and selected the different kernels, and waiting a few minutes for the system to quiet down after the reboot.


Steps to Reproduce:
1. boot
2. open a single xterm
3. run gkrellm and watch the cpu temperature

Actual results:

With 4.4.7-300.fc23.x86_64 it never drops below 59 C.
With 4.4.6-301.fc23.x86_64 it drops to 54 C.

Expected results:

Booting with 4.4.7-300.fc23.x86_64 and leaving the system idle would let the cpu get cool enough that the fan goes off.

Additional info:

The first few lines of top -b.

top - 04:11:40 up 18 min,  3 users,  load average: 0.01, 0.09, 0.10
Tasks: 261 total,   1 running, 260 sleeping,   0 stopped,   0 zombie
%Cpu(s):  2.9 us,  1.2 sy,  0.1 ni, 95.3 id,  0.5 wa,  0.0 hi,  0.0 si,  0.0 st
KiB Mem :  8083156 total,  4990804 free,   993864 used,  2098488 buff/cache
KiB Swap:        0 total,        0 free,        0 used.  6833396 avail Mem

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND
    1 root      20   0  191820   6076   4020 S   0.0  0.1   0:01.34 systemd
    2 root      20   0       0      0      0 S   0.0  0.0   0:00.00 kthreadd
    3 root      20   0       0      0      0 S   0.0  0.0   0:00.00 ksoftirqd/0
    5 root       0 -20       0      0      0 S   0.0  0.0   0:00.00 kworker/0:0H
    7 root      20   0       0      0      0 S   0.0  0.0   0:01.39 rcu_sched
    8 root      20   0       0      0      0 S   0.0  0.0   0:00.00 rcu_bh
    9 root      20   0       0      0      0 S   0.0  0.0   0:01.34 rcuos/0
   10 root      20   0       0      0      0 S   0.0  0.0   0:00.00 rcuob/0
   11 root      rt   0       0      0      0 S   0.0  0.0   0:00.00 migration/0
   12 root      rt   0       0      0      0 S   0.0  0.0   0:00.00 watchdog/0
   13 root      rt   0       0      0      0 S   0.0  0.0   0:00.00 watchdog/1
   14 root      rt   0       0      0      0 S   0.0  0.0   0:00.01 migration/1
   15 root      20   0       0      0      0 S   0.0  0.0   0:00.00 ksoftirqd/1
   17 root       0 -20       0      0      0 S   0.0  0.0   0:00.00 kworker/1:0H
   18 root      20   0       0      0      0 S   0.0  0.0   0:00.24 rcuos/1
   19 root      20   0       0      0      0 S   0.0  0.0   0:00.00 rcuob/1
   20 root      rt   0       0      0      0 S   0.0  0.0   0:00.00 watchdog/2
   21 root      rt   0       0      0      0 S   0.0  0.0   0:00.00 migration/2
   22 root      20   0       0      0      0 S   0.0  0.0   0:00.00 ksoftirqd/2
   24 root       0 -20       0      0      0 S   0.0  0.0   0:00.00 kworker/2:0H
   25 root      20   0       0      0      0 S   0.0  0.0   0:00.14 rcuos/2
   26 root      20   0       0      0      0 S   0.0  0.0   0:00.00 rcuob/2
   27 root      rt   0       0      0      0 S   0.0  0.0   0:00.00 watchdog/3
   28 root      rt   0       0      0      0 S   0.0  0.0   0:00.00 migration/3
   29 root      20   0       0      0      0 S   0.0  0.0   0:00.00 ksoftirqd/3

Comment 1 William Bader 2016-04-28 01:31:37 UTC
Someone reported a similar problem on a Ubuntu forum when upgrading from 4.4.0 to 4.4.8.

http://askubuntu.com/questions/763896/battery-life-reduced-after-upgrade-to-kernel-4-4-8-16-04-lts
Battery life reduced after upgrade to kernel 4.4.8 (16.04 LTS)
"I upgraded from 4.4.0 kernel to 4.4.8 due to unability to suspend/hybernate my Ubuntu 16.04 LTS on Lenovo z51-70 and now it would seem my battery life has somehow halved. I used to be able to have 2.5 hours on average, now as soon as I plug out, the battery indicator shows 1.27 h. I have not installed any new software. How can I notice what's causing the draining?"

Comment 2 Josh Boyer 2016-05-27 13:24:54 UTC
Is this still happening with 4.5.y?

Comment 3 William Bader 2016-05-29 12:29:35 UTC
Fedora 23 is still at 4.4.9-300.fc23.x86_64
I left the PC idle for about half an hour (only xterms open), and the cpu temperature came down to 54.
I'll try again when Fedora 23 pushes a 4.5 kernel.

Comment 4 William Bader 2016-06-04 04:08:16 UTC
Fedora 23 just pushed 4.5.5-201.fc23.x86_64. I rebooted and let it sit for a while, and when the system is idle, the cpu is 54 C, the same as for 4.4.9.

Comment 5 Laura Abbott 2016-09-23 19:43:08 UTC
*********** MASS BUG UPDATE **************
 
We apologize for the inconvenience.  There is a large number of bugs to go through and several of them have gone stale.  Due to this, we are doing a mass bug update across all of the Fedora 23 kernel bugs.
 
Fedora 23 has now been rebased to 4.7.4-100.fc23.  Please test this kernel update (or newer) and let us know if you issue has been resolved or if it is still present with the newer kernel.
 
If you have moved on to Fedora 24 or 25, and are still experiencing this issue, please change the version to Fedora 24 or 25.
 
If you experience different issues, please open a new bug report for those.

Comment 6 Laura Abbott 2016-10-26 16:53:39 UTC
*********** MASS BUG UPDATE **************
This bug is being closed with INSUFFICIENT_DATA as there has not been a response in 4 weeks. If you are still experiencing this issue, please reopen and attach the relevant data from the latest kernel you are running and any data that might have been requested previously.

Comment 7 William Bader 2019-11-19 16:45:23 UTC
I get an automated email about this every day. I am hoping that posting this comment will end the emails.
By the way, I have the same laptop, now with kernel 5.3.11-200.fc30.x86_64, and the idle temperature now is around 54C.


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