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From:   Vladimir Oltean <olteanv@gmail.com>
Date:   Wed, 10 Jun 2020 17:37:22 +0300
Message-ID: <CA+h21hp8ANbZw63UAy5cDx389j6pSOHUG7t1mR+rbQcrFLROyw@mail.gmail.com>
Subject: Re: stress-ng --hrtimers hangs system
To:     Kurt Kanzenbach <kurt.kanzenbach@linutronix.de>
Cc:     linux-rt-users@vger.kernel.org,
        lkml <linux-kernel@vger.kernel.org>, rcu@vger.kernel.org,
        Colin King <colin.king@canonical.com>
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Hi Kurt,

On Wed, 10 Jun 2020 at 08:58, Kurt Kanzenbach
<kurt.kanzenbach@linutronix.de> wrote:
>
> Hi Vladimir,
>
> On Tue Jun 09 2020, Vladimir Oltean wrote:
> > Just out of curiosity, what and how many CPU cores does your ARM64 box
> > have, and what frequency are you running them at?
> > Mine is a dual-core A72 machine running at 1500 MHz.
>
> That particular machine has a dual core Cortex A53 running at 1GHz.
>
> Thanks,
> Kurt

Ok, I just noticed that you said "v5.6*-rt*".
So I re-tested that 5.4 downstream kernel again that hanged before,
just applied the -rt1 patchset on top. And it's actually working fine
now, no hangs, no RCU stalls, no need to reduce sched_rt_runtime_us.
So maybe it's something related to the config?

Thanks,
-Vladimir