Messages in this thread | | | From | Claudio Scordino <> | Subject | Help: Using cpufreq from kernel level | Date | Sat, 17 Dec 2005 13:10:33 -0500 |
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Hi all,
I'm writing a kernel module that needs to get info about the available frequencies on the current processor and to periodically change the current frequency.
At user level it can be done through
/sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed
but I have no idea how to implement it at kernel level.
I tried to declare
extern struct cpufreq_driver *cpufreq_driver; extern struct cpufreq_policy *cpufreq_cpu_data[NR_CPUS]; extern spinlock_t cpufreq_driver_lock; extern ssize_t show_available_freqs (struct cpufreq_policy *policy, char *buf);
and to do
char buffer [100000] = "\n"; spin_lock_irqsave(&cpufreq_driver_lock, flags); show_available_freqs(cpufreq_cpu_data[0], buffer); spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
but it crashes the system.
Please, can somebody tell me how this can be done ?
Many thanks,
Claudio Scordino - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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