Public bug reported:
Binary package hint: powernowd
There is a strange behavior with powernowd, or with components of an
underlying cpufreq, on Intel's dual core CPUs. The expectation is that
dual core CPUs can switch speed of each core independently from one
another. After fresh reboot, powernowd is doing this exactly as expected
for a while. Aapproximately 30 min after reboot, switching of CPU speed
becomes synchronous among cores, meaning, if one core goes up with the
speed, the other goes up too, and vice versa. Cores never switch speed
independently (asynchronous) from one another after that. This pattern
is observed by simultaneously having two CPU frequency monitors, one for
CPU0 and other for CPU1. Simple restarting the powernowd does not affect
this synchronous behavior, once it has started.
Release is: Ubuntu 8.04.1
$ uname -a
Linux xxx 2.6.24-19-generic #1 SMP Fri Jul 11 21:01:46 UTC 2008 x86_64 GNU/Linux
$ cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 23
model name : Intel(R) Core(TM)2 Duo CPU T9300 @ 2.50GHz
stepping : 6
cpu MHz : 800.000
cache size : 6144 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 2
fpu : yes
fpu_exception : yes
cpuid level : 10
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 syscall nx lm
constant_tsc arch_perfmon pebs bts rep_good pni monitor ds_cpl vmx est tm2
ssse3 cx16 xtpr sse4_1 lahf_lm ida
bogomips : 4994.60
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 : 23
model name : Intel(R) Core(TM)2 Duo CPU T9300 @ 2.50GHz
stepping : 6
cpu MHz : 800.000
cache size : 6144 KB
physical id : 0
siblings : 2
core id : 1
cpu cores : 2
fpu : yes
fpu_exception : yes
cpuid level : 10
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 syscall nx lm
constant_tsc arch_perfmon pebs bts rep_good pni monitor ds_cpl vmx est tm2
ssse3 cx16 xtpr sse4_1 lahf_lm ida
bogomips : 4987.54
clflush size : 64
cache_alignment : 64
address sizes : 36 bits physical, 48 bits virtual
power management:
$ cpufreq-info
cpufrequtils 002: cpufreq-info (C) Dominik Brodowski 2004-2006
Report errors and bugs to [EMAIL PROTECTED], please.
analyzing CPU 0:
driver: acpi-cpufreq
CPUs which need to switch frequency at the same time: 0 1
hardware limits: 800 MHz - 2.50 GHz
available frequency steps: 2.50 GHz, 2.50 GHz, 2.00 GHz, 1.60 GHz, 1.20 GHz,
800 MHz
available cpufreq governors: conservative, userspace, powersave, ondemand,
performance
current policy: frequency should be within 800 MHz and 2.50 GHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 800 MHz.
analyzing CPU 1:
driver: acpi-cpufreq
CPUs which need to switch frequency at the same time: 0 1
hardware limits: 800 MHz - 2.50 GHz
available frequency steps: 2.50 GHz, 2.50 GHz, 2.00 GHz, 1.60 GHz, 1.20 GHz,
800 MHz
available cpufreq governors: conservative, userspace, powersave, ondemand,
performance
current policy: frequency should be within 800 MHz and 2.50 GHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 800 MHz.
** Affects: powernowd (Ubuntu)
Importance: Undecided
Status: New
--
powernowd cant switch speed on dual cores independently
https://bugs.launchpad.net/bugs/250976
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
--
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
