Re: [PATCH v2 1/2] cpufreq_stats: Adds sysfs file /sys/devices/system/cpu/cpufreq/current_in_state

On Thu, May 14, 2015 at 7:48 PM, Viresh Kumar [off-list ref] wrote:

I am not replying for concept here, as sched maintainers are in a
better position for that, but a nit below..

On 14-05-15, 17:12, Ruchi Kandoi wrote:

quoted

Adds the sysfs file for userspace to initialize the active current
values for all the cores at each of the frequencies.

The format for storing the values is as follows:
echo "CPU<cpu#>:<freq1>=<current in uA> <freq2>=<current>,CPU<cpu#>:
..." > /sys/devices/system/cpu/cpufreq/current_in_state

Why this file? And not
/sys/devices/system/cpu/cpuX/cpufreq/stats/current_in_state ? That way
you don't have to replicate the same information for all CPUs, as the
stats folder can be shared by multiple CPUs (which share their
clock/voltage rails)..

Some of the hand-held devices support hot-plugging of the cpus and
when the core is hot-plugged out the
/sys/devices/system/cpu/cpuX/cpufreq directory is removed too. So it
won't be possible to share folders by multiple CPUs.

--
viresh