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From: Greg KH <gregkh@linuxfoundation.org>
To: Lukasz Luba <lukasz.luba@arm.com>
Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
	rjw@rjwysocki.net, rafael@kernel.org, ionela.voinescu@arm.com,
	Dietmar.Eggemann@arm.com
Subject: Re: [PATCH] PM / EM: postpone creating the debugfs dir till fs_initcall
Date: Tue, 23 Mar 2021 16:26:06 +0100	[thread overview]
Message-ID: <YFoIjt3E+MIK3yQQ@kroah.com> (raw)
In-Reply-To: <20210323145608.29832-1-lukasz.luba@arm.com>

On Tue, Mar 23, 2021 at 02:56:08PM +0000, Lukasz Luba wrote:
> The debugfs directory '/sys/kernel/debug/energy_model' is needed before
> the Energy Model registration can happen. With the recent change in
> debugfs subsystem it's not allowed to create this directory at early stage
> (core_initcall). Thus creating this directory would fail.
> Postpone the creation of the EM debug dir to later stage: fs_initcall.
> It should be safe since all clients: CPUFreq drivers, Devfreq drivers will
> be initialized in later stages.
> The custom debug log below prints the time of creation the EM debug dir at
> fs_initcall and successful registration of EMs at later stages.
> 
> [    1.505717] energy_model: creating rootdir
> [    3.698307] cpu cpu0: EM: created perf domain
> [    3.709022] cpu cpu1: EM: created perf domain
> 
> fixes: 56348560d495 ("debugfs: do not attempt to create a new file before the filesystem is initalized")
> Reported-by: Ionela Voinescu <ionela.voinescu@arm.com>
> Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
> ---
> Hi Rafael,
> 
> Please take this patch into your PM v5.12 fixes. The change described in
> the patch above landed in v5.12-rc1. Some of our EAS/EM tests are failing.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

  reply	other threads:[~2021-03-23 15:26 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-23 14:56 [PATCH] PM / EM: postpone creating the debugfs dir till fs_initcall Lukasz Luba
2021-03-23 15:26 ` Greg KH [this message]
2021-03-23 15:57   ` Lukasz Luba
2021-03-23 18:55     ` Rafael J. Wysocki
2021-03-24  9:39       ` Lukasz Luba

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