linux-pm.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Viresh Kumar <viresh.kumar@linaro.org>
To: Andy Tang <andy.tang@nxp.com>
Cc: "rjw@rjwysocki.net" <rjw@rjwysocki.net>,
	"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>
Subject: Re: [EXT] Re: Ask for help about cpufreq issue
Date: Wed, 12 Feb 2020 17:20:54 +0530	[thread overview]
Message-ID: <20200212115054.eouh7e42uqlcweo3@vireshk-i7> (raw)
In-Reply-To: <VI1PR04MB43334811F21E85BD9DACE259F31B0@VI1PR04MB4333.eurprd04.prod.outlook.com>

On 12-02-20, 10:11, Andy Tang wrote:
> Hi Viresh,
> 
> I have another cpufreq issue on our lx2160a platform which has 16 cores and 8 clusters.
> 
> Cpufreq works well for ondemand, performance governor. 
> But for conservative governor, even though cpu usage is almost zero, but some cpus are not
> work on the lowest frequency sometimes. It keeps bouncing from the lowest frequency
> to the other higher frequencies. 
> The defaut values are used for the tunable for conservative governor.
> In summary, why cpu doesn't work at the lowest frequency even the cpu load is almost zero?
> 
> root@lx2160ardb:/sys/devices/system/cpu# cat cpufreq/conservative/ 
> down_threshold        freq_step             ignore_nice_load      sampling_down_factor  sampling_rate         up_threshold          
> root@lx2160ardb:/sys/devices/system/cpu# cat cpufreq/conservative/*
> 20

Try increasing down_threshold to a value of 50 (i.e. we reduce
frequency if the load is below 50%) and see if it makes a difference.

I believe something is running on the CPU, that you are unaware of.
Try doing tracing to see what's going on all CPUs.

-- 
viresh

  reply	other threads:[~2020-02-12 11:50 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-07  5:09 Ask for help about cpufreq issue Andy Tang
2020-02-07  5:23 ` Viresh Kumar
2020-02-07  6:03   ` [EXT] " Andy Tang
2020-02-07  7:05     ` Viresh Kumar
2020-02-11  4:20       ` Andy Tang
2020-02-11  5:53         ` Viresh Kumar
2020-02-11  6:23           ` Andy Tang
2020-02-11  6:34             ` Viresh Kumar
2020-02-11  7:20               ` Andy Tang
2020-02-12 10:11               ` Andy Tang
2020-02-12 11:50                 ` Viresh Kumar [this message]
2020-02-13  8:18                   ` Andy Tang
2020-02-13  8:48                     ` Viresh Kumar
2020-02-13  9:12                       ` Andy Tang
2020-02-13  9:15                         ` Viresh Kumar
2020-02-13  9:21                           ` Andy Tang
2020-02-14 10:00                       ` Andy Tang
2020-02-17  8:22                         ` Viresh Kumar

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200212115054.eouh7e42uqlcweo3@vireshk-i7 \
    --to=viresh.kumar@linaro.org \
    --cc=andy.tang@nxp.com \
    --cc=linux-pm@vger.kernel.org \
    --cc=rjw@rjwysocki.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).