Re: [PATCH 0/2] PM / devfreq: Add debugfs support

From: Kamil Konieczny
Date: Thu Jan 09 2020 - 10:06:36 EST


Hi,

On 07.01.2020 10:05, Chanwoo Choi wrote:
> Add debugfs interface to provide debugging information of devfreq device.
> It contains 'devfreq_summary' and 'debug_transitions' debugfs file
> in order to provide the simple profiling to user via debugfs
> without any specific profiling tool.
>
> [Added debugfs file]
> - "/sys/kernel/debug/devfreq/devfreq_summary"
> : Show the summary of the registered devfreq devices.
> - "/sys/kernel/debug/devfreq/devfreq_transitions"
> : Show the frequency transition of the registered devfreq devices.
>
> Recommend the each patch to check the detailed description
> of each fields of both devfreq_summary and devfreq_transitions.
>
> This series contains the patch[1] and add the patch2 for 'devfreq_transitions'
> [1] https://patchwork.kernel.org/patch/11320265/
> - [v3] PM / devfreq: Add debugfs support with devfreq_summary file
>
>
> For example on Exynos5422-based Odroid-XU3 board,
> - In order to show the multiple governors on devfreq_summay result,
> change the governor of devfreq0 from simple_ondemand to userspace.
>
> $ cat /sys/kernel/debug/devfreq/devfreq_summary
> dev_name dev parent_dev governor polling_ms cur_freq_hz min_freq_hz max_freq_hz

Imho either drop "_hz" or change it to "_Hz".

> ------------------------------ ---------- ---------- --------------- ---------- ------------ ------------ ------------
> 10c20000.memory-controller devfreq0 userspace 0 206000000 165000000 825000000
> soc:bus_wcore devfreq1 simple_ondemand 50 532000000 88700000 532000000
> soc:bus_noc devfreq2 devfreq1 passive 0 111000000 66600000 111000000
> soc:bus_fsys_apb devfreq3 devfreq1 passive 0 222000000 111000000 222000000
> soc:bus_fsys devfreq4 devfreq1 passive 0 200000000 75000000 200000000
> soc:bus_fsys2 devfreq5 devfreq1 passive 0 200000000 75000000 200000000
> soc:bus_mfc devfreq6 devfreq1 passive 0 333000000 83250000 333000000
> soc:bus_gen devfreq7 devfreq1 passive 0 266000000 88700000 266000000
> soc:bus_peri devfreq8 devfreq1 passive 0 66600000 66600000 66600000
> soc:bus_g2d devfreq9 devfreq1 passive 0 0 83250000 333000000

Imho it better looks with freq aligned to right, eg.:

soc:bus_gen devfreq7 devfreq1 passive 0 266000000 88700000 266000000
soc:bus_peri devfreq8 devfreq1 passive 0 66600000 66600000 66600000
soc:bus_g2d devfreq9 devfreq1 passive 0 0 83250000 333000000

> soc:bus_g2d_acp devfreq10 devfreq1 passive 0 0 66500000 266000000
> soc:bus_jpeg devfreq11 devfreq1 passive 0 0 75000000 300000000
> soc:bus_jpeg_apb devfreq12 devfreq1 passive 0 0 83250000 166500000
> soc:bus_disp1_fimd devfreq13 devfreq1 passive 0 0 120000000 200000000
> soc:bus_disp1 devfreq14 devfreq1 passive 0 0 120000000 300000000
> soc:bus_gscl_scaler devfreq15 devfreq1 passive 0 0 150000000 300000000
> soc:bus_mscl devfreq16 devfreq1 passive 0 0 84000000 666000000
>
> $ cat /sys/kernel/debug/devfreq/devfreq_transitions
> time_ms dev_name dev parent_dev load_% old_freq_hz new_freq_hz
> ---------- ------------------------------ ---------- ---------- ---------- ------------ ------------
> 14600 soc:bus_noc devfreq2 devfreq1 0 100000000 67000000
> 14600 soc:bus_fsys_apb devfreq3 devfreq1 0 200000000 100000000
> 14600 soc:bus_fsys devfreq4 devfreq1 0 200000000 100000000
> 14600 soc:bus_fsys2 devfreq5 devfreq1 0 150000000 75000000
> 14602 soc:bus_mfc devfreq6 devfreq1 0 222000000 96000000
> 14602 soc:bus_gen devfreq7 devfreq1 0 267000000 89000000
> 14602 soc:bus_g2d devfreq9 devfreq1 0 300000000 84000000
> 14602 soc:bus_g2d_acp devfreq10 devfreq1 0 267000000 67000000
> 14602 soc:bus_jpeg devfreq11 devfreq1 0 300000000 75000000
> 14602 soc:bus_jpeg_apb devfreq12 devfreq1 0 167000000 84000000
> 14603 soc:bus_disp1_fimd devfreq13 devfreq1 0 200000000 120000000
> 14603 soc:bus_disp1 devfreq14 devfreq1 0 300000000 120000000
> 14606 soc:bus_gscl_scaler devfreq15 devfreq1 0 300000000 150000000
> 14606 soc:bus_mscl devfreq16 devfreq1 0 333000000 84000000
> 14608 soc:bus_wcore devfreq1 9 333000000 84000000
> 14783 10c20000.memory-controller devfreq0 35 825000000 633000000
> 15873 soc:bus_wcore devfreq1 41 84000000 400000000
> 15873 soc:bus_noc devfreq2 devfreq1 0 67000000 100000000
> [snip]
>
>
> Depends on:
> It depends on patch[2] for preventing the merge conflic.
> [2] https://patchwork.kernel.org/patch/11320257/
> - PM / devfreq: Add missing function description and rename static functions
>
> Chanwoo Choi (2):
> PM / devfreq: Add debugfs support with devfreq_summary file
> PM / devfreq: Add devfreq_transitions debugfs file
>
> drivers/devfreq/Kconfig | 13 ++
> drivers/devfreq/devfreq.c | 206 +++++++++++++++++++++++++++++
> drivers/devfreq/governor.h | 3 +
> drivers/devfreq/governor_passive.c | 2 +
> include/linux/devfreq.h | 1 +
> 5 files changed, 225 insertions(+)
>

--
Best regards,
Kamil Konieczny
Samsung R&D Institute Poland