On 25 August 2014 17:58, Harry van Haaren <harryhaaren@xxxxxxxxx> wrote: > I'm attempting to squeeze the lowest audio-latency out of a laptop as possible, > and in doing so would like to set the CPU to performance. > > CPU in laptop: Intel(R) Core(TM)2 Duo CPU T7300 @ 2.00GHz > > $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors > ondemand performance > > $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_driver > acpi-cpufreq > > # Attempt to set performance governer > $ echo "performance" >/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor > bash: echo: write error: Invalid argument > > # Attempt to set min freq of 2GHz (max) of this core2duo > $ echo 2000000 > /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq > bash: /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq: Permission denied You tried both these as root? Even 'sudo' may not work.. I haven't seen the rt code since sometime, what tag should I look at ? I don't think there should be any such issues there.. > As far as I can tell, it is currently impossible on the -rt kernel to > change CPU governer? > This is necessary for reliable low-latency audio for laptop musicians. > > What is necessary to fix cpufreq on -rt? Cheers, -Harry > > PS: I've CC'd maintainers of cpufreq, I hope that's OK, otherwise > please inform me of > normal practices on linux-rt-users ML That's fine I suppose. -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
