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From:   Rui Salvaterra <rsalvaterra@gmail.com>
Date:   Thu, 13 Apr 2023 16:32:32 +0100
Message-ID: <CALjTZva=JHsckrBeHgJcd-_TDMgYgmZGcXavJ=GhPr7VQCOF5g@mail.gmail.com>
Subject: Re: [BUG?] INFO: rcu_sched detected expedited stalls on CPUs/tasks: {
 0-.... } 3 jiffies s: 309 root: 0x1/.
To:     paulmck@kernel.org
Cc:     Jani Nikula <jani.nikula@linux.intel.com>, rodrigo.vivi@intel.com,
        tvrtko.ursulin@linux.intel.com, intel-gfx@lists.freedesktop.org,
        dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
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Hi, Paul,

On Thu, 13 Apr 2023 at 15:43, Paul E. McKenney <paulmck@kernel.org> wrote:
>
> My guess would be that you have CONFIG_RCU_EXP_CPU_STALL_TIMEOUT set to
> some small non-zero number, for example, you might have set up a recent
> Android .config or some such.  The default of zero would give you about
> 21 seconds rather than the three jiffies that you are seeing.
>
> Could you please check your .config?

Well, this is embarrassing. I can't fathom why/how, but I had it set
to 20, on this machine. That is, 20 millisseconds. I guess its a
miracle I haven't seen *more* expedited RCU traces. Sorry for the
noise, everyone.

Kind regards,
Rui