Fixing Rafael's id.. On 25 August 2014 19:25, Viresh Kumar <viresh.kumar@xxxxxxxxxx> wrote: > 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
