Bug 246813

Summary: cpu running f7 is a lot hotter unless nohz=off is used
Product: [Fedora] Fedora Reporter: Christof Damian <christof>
Component: kernelAssignee: Kernel Maintainer List <kernel-maint>
Status: CLOSED INSUFFICIENT_DATA QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: low Docs Contact:
Priority: low    
Version: 7CC: chris.brown, tglx
Target Milestone: ---   
Target Release: ---   
Hardware: i386   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2007-09-18 07:17:47 UTC Type: ---
Regression: --- Mount Type: ---
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Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description Christof Damian 2007-07-05 06:29:58 UTC
Description of problem:

My Duron 1000 machine is running a lot hotter since I installed f7. It used to
have a 54-58C CPU temperature, now it is 58-62C. I noticed that this is reduced
to nearly the previous value if I use nohz=off

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

kernel-2.6.21-1.3228.fc7

How reproducible:

Normal computer use
  
Additional info:

http://smolt.fedoraproject.org/show?UUID=e2b43b83-2dce-4a57-bc92-16f7d6cabb1d

Comment 1 Chuck Ebbert 2007-07-05 16:33:59 UTC
Is cpufreq reducing the CPU speed when nohz is enabled?

Load the cpufreq_stats module ('modprobe cpufreq_stats'),
then look in:

  /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state

Compare with and without nohz.


Comment 2 Christof Damian 2007-07-05 16:57:58 UTC
I don't think that my Duron supports cpufreq. Here is the /proc/cpuinfo

processor       : 0
vendor_id       : AuthenticAMD
cpu family      : 6
model           : 7
model name      : AMD Duron(tm) 
stepping        : 0
cpu MHz         : 999.050
cache size      : 64 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 1
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat
pse36 mmx fxsr sse syscall mmxext 3dnowext 3dnow up ts
bogomips        : 1999.76
clflush size    : 32


Comment 3 Thomas Gleixner 2007-07-11 05:15:15 UTC
Can you please provide a full boot log and the output of /proc/timer_list, when
booted with nohz enabled ?


Comment 4 Christopher Brown 2007-09-17 20:32:17 UTC
Hello,

I'm reviewing this bug as part of the kernel bug triage project, an attempt to
isolate current bugs in the fedora kernel.

http://fedoraproject.org/wiki/KernelBugTriage

I am CC'ing myself to this bug and will try and assist you in resolving it if I can.

There hasn't been much activity on this bug for a while. Could you tell me if
you are still having problems with the latest kernel?

If the problem no longer exists then please close this bug or I'll do so in a
few days if there is no additional information lodged.

Cheers
Chris

Comment 5 Christof Damian 2007-09-18 07:17:47 UTC
I am closing this bug now. I don't have the time to debug it at the moment as it
takes a long time to notice changes. I am also not sure if the problem still exists.