Re: [PATCH v4] cpufreq: stats: Add 'load_table' debugfs file to showaccumulated data of CPUs

From: Viresh Kumar
Date: Wed Jul 03 2013 - 02:41:23 EST


On 2 July 2013 16:19, Chanwoo Choi <cw00.choi@xxxxxxxxxxx> wrote:
> Previously, I sent two reply about your reply. But, Please ignore previous reply.
> Those have wrong function flow about creating sysfs file and poor wrong opinion.
>
> I'm so sorry if you're confused.

Its okay.

> OK. I'll create link for CPU[1-3] if multiple core use one cpufreq policy.
> In result, we can check below directory structure.
>
> sh-4.1# ls -al /sys/kernel/debug/cpufreq/
> total 0
> drwxr-xr-x 3 root root 0 Jan 1 09:00 .
> drwx------ 26 root root 0 Jan 1 09:00 ..
> drwxr-xr-x 2 root root 0 Jan 1 09:00 cpu0
> lrwxrwxrwx 1 root root 0 Jan 1 09:00 cpu1 -> ./cpu0
> lrwxrwxrwx 1 root root 0 Jan 1 09:00 cpu2 -> ./cpu0
> lrwxrwxrwx 1 root root 0 Jan 1 09:00 cpu3 -> ./cpu0
>
> And then I will create load_table debugfs file below of /sys/kernel/debug/cpufreq/cpu0
> in cpufreq_stats.c

Looks good.

> I understand your opinion. But I have a suggestion for using load_table debugfs file
> if cpufreq governor is performance/powersave.
>
> So, I suggest that performance/powersave governor may need to executes dbs_check_cpu()
> to calculate CPUx load. Sometimes, we need CPUs load on performance/powersave
> govenor because we could get different power-consumption according to CPUs load
> on same cpu frequency when we estimate power-consumption on specific test case.

How will these two call dbs_check_cpu()? We don't have a timer for
those two governors :)

Okay do one thing. Create debugfs and debug/cpufreq/cpuX directory always.
Let load_table contain zero when we have irrelevant governors set for it.

We will see if we want some smart code in place for this or not.
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