Re: CPU frequency scaling on G4 systems
On Mon, 2006-09-25 at 13:19 +0100, Roger Leigh wrote:
> Hi folks,
>
> With current 2.6.17 and 2.8.16 Debian kernels, the following cpufreq
> modules are available:
>
> $ find /lib/modules/$(uname -r) -name 'cpufreq*'
> /lib/modules/2.6.18-1-powerpc/kernel/drivers/cpufreq
> /lib/modules/2.6.18-1-powerpc/kernel/drivers/cpufreq/cpufreq_stats.ko
> /lib/modules/2.6.18-1-powerpc/kernel/drivers/cpufreq/cpufreq_userspace.ko
> /lib/modules/2.6.18-1-powerpc/kernel/drivers/cpufreq/cpufreq_ondemand.ko
> /lib/modules/2.6.18-1-powerpc/kernel/drivers/cpufreq/cpufreq_conservative.ko
> /lib/modules/2.6.18-1-powerpc/kernel/drivers/cpufreq/cpufreq_powersave.ko
>
> However, loading any or all of these modules does not enable frequency
> scaling. You don't get anything under, e.g.
>
> /sys/devices/system/cpu/cpu0/
>
> or under /proc.
>
> What else is needed to get CPU frequency scaling to work? On other
> platforms, there are additional modules under kernel/arch/<arch>, but
> this is not the case for powerpc.
>
> The system in question is a Mac Mini (7447A).
>
On my powerbook 5,6, 2.6.18-rc6:
corsac@hidalgo: zgrep -i cpu_freq /proc/config.gz [~]
CONFIG_CPU_FREQ=y
CONFIG_CPU_FREQ_TABLE=y
# CONFIG_CPU_FREQ_DEBUG is not set
CONFIG_CPU_FREQ_STAT=y
CONFIG_CPU_FREQ_STAT_DETAILS=y
# CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE is not set
CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE=y
CONFIG_CPU_FREQ_GOV_PERFORMANCE=y
CONFIG_CPU_FREQ_GOV_POWERSAVE=y
CONFIG_CPU_FREQ_GOV_USERSPACE=y
CONFIG_CPU_FREQ_GOV_ONDEMAND=y
CONFIG_CPU_FREQ_GOV_CONSERVATIVE=y
CONFIG_CPU_FREQ_PMAC=y
corsac@hidalgo: ls /sys/devices/system/cpu/cpu0/cpufreq [~]
total 0
-r--r--r-- 1 root root 4.0K 2006-09-25 14:25 affected_cpus
-r-------- 1 root root 4.0K 2006-09-25 14:25 cpuinfo_cur_freq
-r--r--r-- 1 root root 4.0K 2006-09-25 14:25 cpuinfo_max_freq
-r--r--r-- 1 root root 4.0K 2006-09-25 14:25 cpuinfo_min_freq
-r--r--r-- 1 root root 4.0K 2006-09-25 14:25
scaling_available_frequencies
-r--r--r-- 1 root root 4.0K 2006-09-25 14:25 scaling_available_governors
-r--r--r-- 1 root root 4.0K 2006-09-25 14:25 scaling_cur_freq
-r--r--r-- 1 root root 4.0K 2006-09-25 14:25 scaling_driver
-rw-r--r-- 1 root root 4.0K 2006-09-25 14:25 scaling_governor
-rw-r--r-- 1 root root 4.0K 2006-09-25 14:25 scaling_max_freq
-rw-r--r-- 1 root root 4.0K 2006-09-25 14:25 scaling_min_freq
-rw-r--r-- 1 root root 4.0K 2006-09-25 14:19 scaling_setspeed
drwxr-xr-x 2 root root 0 1904-01-01 22:56 stats
corsac@hidalgo:
cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors
conservative ondemand powersave userspace performance
corsac@hidalgo:
cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
1499999 749999
corsac@hidalgo: sudo
cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq
749999
Maybe the CPU in the mac mini doesn't support frequency scaling ?
--
Yves-Alexis
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