Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Uladzislau Rezki <urezki@gmail.com>
Date:   Wed, 6 Jul 2022 19:48:20 +0200
To:     Christian =?utf-8?B?S8O2bmln?= <christian.koenig@amd.com>
Cc:     Uladzislau Rezki <urezki@gmail.com>,
        "Alex Xu (Hello71)" <alex_y_xu@yahoo.ca>,
        wireguard@lists.zx2c4.com, "Jason A. Donenfeld" <Jason@zx2c4.com>,
        Joel Fernandes <joel@joelfernandes.org>, paulmck@kernel.org,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Xinhui.Pan@amd.com, linux-kernel@vger.kernel.org,
        amd-gfx@lists.freedesktop.org,
        Suren Baghdasaryan <surenb@google.com>, rcu@vger.kernel.org,
        Hridya Valsaraju <hridya@google.com>,
        Arve =?utf-8?B?SGrDuG5uZXbDpWc=?= <arve@android.com>,
        Theodore Ts'o <tytso@mit.edu>, alexander.deucher@amd.com,
        Todd Kjos <tkjos@android.com>, uladzislau.rezki@sony.com,
        Martijn Coenen <maco@android.com>,
        Christian Brauner <christian@brauner.io>
Subject: Re: CONFIG_ANDROID (was: rcu_sched detected expedited stalls in
 amdgpu after suspend)
Message-ID: <YsXK5A0MiVgHd8Je@pc638.lan>
References: <1656357116.rhe0mufk6a.none.ref@localhost>
 <1656357116.rhe0mufk6a.none@localhost>
 <20220627204139.GL1790663@paulmck-ThinkPad-P17-Gen-1>
 <1656379893.q9yb069erk.none@localhost>
 <20220628041252.GV1790663@paulmck-ThinkPad-P17-Gen-1>
 <1656421946.ic03168yc3.none@localhost>
 <20220628185437.GA1790663@paulmck-ThinkPad-P17-Gen-1>
 <1656443915.mdjoauhqe0.none@localhost>
 <YrtgeSmwLmpzN/zw@pc638>
 <79c6ad70-47d9-47fe-4bb4-33fcf356dd37@amd.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <79c6ad70-47d9-47fe-4bb4-33fcf356dd37@amd.com>
Precedence: bulk

Hello.

On Mon, Jul 04, 2022 at 01:30:50PM +0200, Christian König wrote:
> Hi guys,
> 
> Am 28.06.22 um 22:11 schrieb Uladzislau Rezki:
> > > Excerpts from Paul E. McKenney's message of June 28, 2022 2:54 pm:
> > > > All you need to do to get the previous behavior is to add something like
> > > > this to your defconfig file:
> > > > 
> > > > CONFIG_RCU_EXP_CPU_STALL_TIMEOUT=21000
> > > > 
> > > > Any reason why this will not work for you?
> 
> sorry for jumping in so later, I was on vacation for a week.
> 
> Well when any RCU period is longer than 20ms and amdgpu in the backtrace my
> educated guess is that we messed up some timeout waiting for the hw.
> 
> We usually do wait a few us, but it can be that somebody is waiting for ms
> instead.
> 
> So there are some todos here as far as I can see and It would be helpful to
> get a cleaner backtrace if possible.
> 
Actually CONFIG_ANDROID looks like is going to be removed, so the CONFIG_RCU_EXP_CPU_STALL_TIMEOUT
will not have any dependencies on the CONFIG_ANDROID anymore:

https://lkml.org/lkml/2022/6/29/756

--
Uladzislau Rezki