Bug 33202

Summary:	cpufreq-info 008 only reports maximum "current frequency", contradicts cpufreq stats and /proc/cpuinfo
Product:	Power Management	Reporter:	Leho Kraav (leho)
Component:	cpufreq	Assignee:	cpufreq
Status:	CLOSED WILL_NOT_FIX
Severity:	normal	CC:	linux, rui.zhang
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	2.6.38.2-zen	Subsystem:
Regression:	No	Bisected commit-id:

Description Leho Kraav 2011-04-13 07:02:04 UTC

Linux travelmate 2.6.38.2-zen #56 ZEN SMP Tue Apr 12 14:06:11 EEST 2011 i686 Intel(R) Core(TM) i3 CPU U 330 @ 1.20GHz GenuineIntel GNU/Linux

leho@travelmate ~ $ sudo cpufreq-info
cpufrequtils 008: cpufreq-info (C) Dominik Brodowski 2004-2009
Report errors and bugs to cpufreq@vger.kernel.org, please.
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 10.0 us.
  hardware limits: 666 MHz - 1.20 GHz
  available frequency steps: 1.20 GHz, 1.07 GHz, 933 MHz, 799 MHz, 666 MHz
  available cpufreq governors: ondemand, userspace, powersave, conservative, performance
  current policy: frequency should be within 666 MHz and 1.20 GHz.
                  The governor "conservative" may decide which speed to use
                  within this range.
  current CPU frequency is 1.20 GHz (asserted by call to hardware).
  cpufreq stats: 1.20 GHz:1.00%, 1.07 GHz:0.78%, 933 MHz:0.98%, 799 MHz:1.59%, 666 MHz:95.65%  (9376)
analyzing CPU 1:
  driver: acpi-cpufreq
  CPUs which run at the same hardware frequency: 1
  CPUs which need to have their frequency coordinated by software: 1
  maximum transition latency: 10.0 us.
  hardware limits: 666 MHz - 1.20 GHz
  available frequency steps: 1.20 GHz, 1.07 GHz, 933 MHz, 799 MHz, 666 MHz
  available cpufreq governors: ondemand, userspace, powersave, conservative, performance
  current policy: frequency should be within 666 MHz and 1.20 GHz.
                  The governor "conservative" may decide which speed to use
                  within this range.
  current CPU frequency is 1.20 GHz (asserted by call to hardware).
  cpufreq stats: 1.20 GHz:0.51%, 1.07 GHz:0.44%, 933 MHz:0.85%, 799 MHz:1.46%, 666 MHz:96.73%  (378)
analyzing CPU 2:
  driver: acpi-cpufreq
  CPUs which run at the same hardware frequency: 2
  CPUs which need to have their frequency coordinated by software: 2
  maximum transition latency: 10.0 us.
  hardware limits: 666 MHz - 1.20 GHz
  available frequency steps: 1.20 GHz, 1.07 GHz, 933 MHz, 799 MHz, 666 MHz
  available cpufreq governors: ondemand, userspace, powersave, conservative, performance
  current policy: frequency should be within 666 MHz and 1.20 GHz.
                  The governor "conservative" may decide which speed to use
                  within this range.
  current CPU frequency is 1.20 GHz (asserted by call to hardware).
  cpufreq stats: 1.20 GHz:0.82%, 1.07 GHz:0.67%, 933 MHz:0.97%, 799 MHz:1.48%, 666 MHz:96.05%  (416)
analyzing CPU 3:
  driver: acpi-cpufreq
  CPUs which run at the same hardware frequency: 3
  CPUs which need to have their frequency coordinated by software: 3
  maximum transition latency: 10.0 us.
  hardware limits: 666 MHz - 1.20 GHz
  available frequency steps: 1.20 GHz, 1.07 GHz, 933 MHz, 799 MHz, 666 MHz
  available cpufreq governors: ondemand, userspace, powersave, conservative, performance
  current policy: frequency should be within 666 MHz and 1.20 GHz.
                  The governor "conservative" may decide which speed to use
                  within this range.
  current CPU frequency is 1.20 GHz (asserted by call to hardware).
  cpufreq stats: 1.20 GHz:0.20%, 1.07 GHz:0.20%, 933 MHz:0.47%, 799 MHz:0.70%, 666 MHz:98.43%  

cat /proc/cpuinfo:
(234)
processor	: 0
vendor_id	: GenuineIntel
cpu family	: 6
model		: 37
model name	: Intel(R) Core(TM) i3 CPU       U 330  @ 1.20GHz
stepping	: 5
cpu MHz		: 666.000
cache size	: 3072 KB
physical id	: 0
siblings	: 4
core id		: 0
cpu cores	: 2
apicid		: 0
initial apicid	: 0
fdiv_bug	: no
hlt_bug		: no
f00f_bug	: no
coma_bug	: no
fpu		: yes
fpu_exception	: yes
cpuid level	: 11
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx rdtscp lm constant_tsc arch_perfmon pebs bts xtopology nonstop_tsc aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm sse4_1 sse4_2 popcnt lahf_lm arat dts tpr_shadow vnmi flexpriority ept vpid
bogomips	: 2400.28
clflush size	: 64
cache_alignment	: 64
address sizes	: 36 bits physical, 48 bits virtual
power management:

processor	: 1
vendor_id	: GenuineIntel
cpu family	: 6
model		: 37
model name	: Intel(R) Core(TM) i3 CPU       U 330  @ 1.20GHz
stepping	: 5
cpu MHz		: 666.000
cache size	: 3072 KB
physical id	: 0
siblings	: 4
core id		: 0
cpu cores	: 2
apicid		: 1
initial apicid	: 1
fdiv_bug	: no
hlt_bug		: no
f00f_bug	: no
coma_bug	: no
fpu		: yes
fpu_exception	: yes
cpuid level	: 11
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx rdtscp lm constant_tsc arch_perfmon pebs bts xtopology nonstop_tsc aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm sse4_1 sse4_2 popcnt lahf_lm arat dts tpr_shadow vnmi flexpriority ept vpid
bogomips	: 2400.11
clflush size	: 64
cache_alignment	: 64
address sizes	: 36 bits physical, 48 bits virtual
power management:

processor	: 2
vendor_id	: GenuineIntel
cpu family	: 6
model		: 37
model name	: Intel(R) Core(TM) i3 CPU       U 330  @ 1.20GHz
stepping	: 5
cpu MHz		: 666.000
cache size	: 3072 KB
physical id	: 0
siblings	: 4
core id		: 2
cpu cores	: 2
apicid		: 4
initial apicid	: 4
fdiv_bug	: no
hlt_bug		: no
f00f_bug	: no
coma_bug	: no
fpu		: yes
fpu_exception	: yes
cpuid level	: 11
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx rdtscp lm constant_tsc arch_perfmon pebs bts xtopology nonstop_tsc aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm sse4_1 sse4_2 popcnt lahf_lm arat dts tpr_shadow vnmi flexpriority ept vpid
bogomips	: 2400.08
clflush size	: 64
cache_alignment	: 64
address sizes	: 36 bits physical, 48 bits virtual
power management:

processor	: 3
vendor_id	: GenuineIntel
cpu family	: 6
model		: 37
model name	: Intel(R) Core(TM) i3 CPU       U 330  @ 1.20GHz
stepping	: 5
cpu MHz		: 666.000
cache size	: 3072 KB
physical id	: 0
siblings	: 4
core id		: 2
cpu cores	: 2
apicid		: 5
initial apicid	: 5
fdiv_bug	: no
hlt_bug		: no
f00f_bug	: no
coma_bug	: no
fpu		: yes
fpu_exception	: yes
cpuid level	: 11
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx rdtscp lm constant_tsc arch_perfmon pebs bts xtopology nonstop_tsc aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm sse4_1 sse4_2 popcnt lahf_lm arat dts tpr_shadow vnmi flexpriority ept vpid
bogomips	: 2398.58
clflush size	: 64
cache_alignment	: 64
address sizes	: 36 bits physical, 48 bits virtual
power management:

at no point does cpufreq-info report a lower "current frequency". i also have a core i5 server in the room that has no such problem. as evident from cpufreq stats, majority of time is in fact spent in the frequency specified by governor so i'd say cpufreq-info is wrong here.

Comment 1 Dominik Brodowski 2011-04-13 10:54:58 UTC

Well, all cpufreq-info does is read out

  /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq

or

  /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq

and then print the value being reported there. Do the values in those files change at all?

Comment 2 Leho Kraav 2011-04-13 12:57:41 UTC

did watch -n 0.1 cat ...

/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq - does not change
/sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq - changes frequencies as expected

am i simply misunderstanding something here?

Comment 3 Leho Kraav 2011-04-14 15:18:44 UTC

after doing parameter changes, cpufreq-info now reports minimum frequencies as well. i may be able to produce a diff but it might be unlikely. im guessing this one can be closed until or if i get some more info.

Comment 4 Zhang Rui 2012-01-18 03:27:03 UTC

(In reply to comment #3)
> im guessing
> this one can be closed until or if i get some more info.

Bug closed.