public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Quentin Perret <qperret@google.com>
To: Thara Gopinath <thara.gopinath@linaro.org>
Cc: mingo@redhat.com, peterz@infradead.org, ionela.voinescu@arm.com,
	vincent.guittot@linaro.org, rui.zhang@intel.com,
	edubezval@gmail.com, linux-kernel@vger.kernel.org,
	amit.kachhap@gmail.com, javi.merino@kernel.org,
	daniel.lezcano@linaro.org
Subject: Re: [Patch v3 7/7] sched: thermal: Enable tuning of decay period
Date: Tue, 15 Oct 2019 11:14:52 +0100	[thread overview]
Message-ID: <20191015101452.GA237548@google.com> (raw)
In-Reply-To: <1571014705-19646-8-git-send-email-thara.gopinath@linaro.org>

Hi Thara,

On Sunday 13 Oct 2019 at 20:58:25 (-0400), Thara Gopinath wrote:
> diff --git a/kernel/sysctl.c b/kernel/sysctl.c
> index 00fcea2..5056c08 100644
> --- a/kernel/sysctl.c
> +++ b/kernel/sysctl.c
> @@ -376,6 +376,13 @@ static struct ctl_table kern_table[] = {
>  		.mode		= 0644,
>  		.proc_handler	= proc_dointvec,
>  	},
> +	{
> +		.procname	= "sched_thermal_decay_coeff",
> +		.data		= &sysctl_sched_thermal_decay_coeff,
> +		.maxlen		= sizeof(unsigned int),
> +		.mode		= 0644,
> +		.proc_handler	= proc_dointvec,

Perhaps change this for 'sched_proc_update_handler' with min and max
values ? Otherwise userspace is allowed to write nonsensical values
here. And since sysctl_sched_thermal_decay_coeff is used to shift, this
can lead to an undefined behaviour.

Also, could we take this sysctl out of SCHED_DEBUG ? I expect this to be
used/tuned on production devices where SCHED_DEBUG should theoretically
be off.

Thanks,
Quentin

  reply	other threads:[~2019-10-15 10:15 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-14  0:58 [Patch v3 0/7] Introduce Thermal Pressure Thara Gopinath
2019-10-14  0:58 ` [Patch v3 1/7] sched/pelt.c: Add support to track thermal pressure Thara Gopinath
2019-10-14 13:55   ` Vincent Guittot
2019-10-16 21:15     ` Thara Gopinath
2019-10-14  0:58 ` [Patch v3 2/7] sched: Add infrastructure to store and update instantaneous " Thara Gopinath
2019-10-14 15:50   ` Vincent Guittot
2019-10-16 21:22     ` Thara Gopinath
2019-10-17  8:44       ` Vincent Guittot
2019-10-17 16:40         ` Thara Gopinath
2019-10-18  8:05           ` Vincent Guittot
2019-10-14  0:58 ` [Patch v3 3/7] sched: Initialize per cpu thermal pressure structure Thara Gopinath
2019-10-14  0:58 ` [Patch v3 4/7] sched/fair: Enable CFS periodic tick to update thermal pressure Thara Gopinath
2019-10-14  0:58 ` [Patch v3 5/7] sched/fair: update cpu_capcity to reflect " Thara Gopinath
2019-10-14  0:58 ` [Patch v3 6/7] thermal/cpu-cooling: Update thermal pressure in case of a maximum frequency capping Thara Gopinath
2019-10-14  0:58 ` [Patch v3 7/7] sched: thermal: Enable tuning of decay period Thara Gopinath
2019-10-15 10:14   ` Quentin Perret [this message]
2019-10-21 21:03     ` Thara Gopinath
2019-10-22  9:03       ` Quentin Perret
2019-10-22 20:36         ` Thara Gopinath

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=20191015101452.GA237548@google.com \
    --to=qperret@google.com \
    --cc=amit.kachhap@gmail.com \
    --cc=daniel.lezcano@linaro.org \
    --cc=edubezval@gmail.com \
    --cc=ionela.voinescu@arm.com \
    --cc=javi.merino@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    --cc=rui.zhang@intel.com \
    --cc=thara.gopinath@linaro.org \
    --cc=vincent.guittot@linaro.org \
    /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