From: Thomas Gleixner <tglx@linutronix.de>
To: Kurt Kanzenbach <kurt.kanzenbach@linutronix.de>,
Vladimir Oltean <olteanv@gmail.com>
Cc: Alison Wang <alison.wang@nxp.com>,
catalin.marinas@arm.com, will@kernel.org, paulmck@kernel.org,
mw@semihalf.com, leoyang.li@nxp.com, vladimir.oltean@nxp.com,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
Anna-Maria Gleixner <anna-maria@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>
Subject: Re: [RFC PATCH] arm64: defconfig: Disable fine-grained task level IRQ time accounting
Date: Mon, 03 Aug 2020 12:49:36 +0200 [thread overview]
Message-ID: <87lfiwm2bj.fsf@nanos.tec.linutronix.de> (raw)
In-Reply-To: <873654m9zi.fsf@kurt>
Kurt,
Kurt Kanzenbach <kurt.kanzenbach@linutronix.de> writes:
> On Thu Jul 30 2020, Vladimir Oltean wrote:
> OK. I've reproduced it on a Marvell Armada SoC with v5.6 mainline. See
> splats below. Running with irq time accounting enabled, kills the
> machine immediately. However, I'm not getting the possible deadlock
> warnings in 8250 as you did. So that might be unrelated.
>
> Unfortunately I have no idea what to debug here.
lets look at the facts we have so far.
1) When irq accounting is disabled, RT throttling kicks in as
expected.
2) With irq accounting the RT throttler does not kick in and the RCU
stall/lockups happen.
Not much, but there is clearly interaction between irq time accounting
and scheduler accounting.
Can you please reduce /proc/sys/kernel/sched_rt_runtime_us in steps of
50000? At least in theory, reduction should bring the throttling back.
Thanks,
tglx
next prev parent reply other threads:[~2020-08-03 10:49 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-29 3:39 [RFC PATCH] arm64: defconfig: Disable fine-grained task level IRQ time accounting Alison Wang
2020-07-29 8:40 ` Kurt Kanzenbach
2020-07-29 8:50 ` [EXT] " Alison Wang
2020-07-29 9:49 ` Vladimir Oltean
2020-07-30 7:23 ` Kurt Kanzenbach
2020-07-30 8:22 ` Vladimir Oltean
2020-08-03 8:04 ` Kurt Kanzenbach
2020-08-03 8:16 ` Vladimir Oltean
2020-08-03 9:51 ` Robin Murphy
2020-08-03 11:38 ` Vladimir Oltean
2020-08-03 11:48 ` Valentin Schneider
2020-08-03 13:24 ` Marc Zyngier
2020-08-03 10:02 ` Thomas Gleixner
2020-08-03 10:49 ` Thomas Gleixner [this message]
2020-08-03 11:41 ` Vladimir Oltean
2020-08-03 15:13 ` Thomas Gleixner
2020-08-03 15:47 ` Valentin Schneider
2020-08-03 16:14 ` Vladimir Oltean
2020-08-03 19:22 ` Thomas Gleixner
2020-08-03 23:59 ` Valentin Schneider
2020-08-05 8:50 ` Dietmar Eggemann
2020-08-05 13:40 ` peterz
2020-08-05 13:56 ` Valentin Schneider
2020-08-05 15:31 ` peterz
2020-08-06 9:41 ` Thomas Gleixner
2020-08-06 11:45 ` peterz
2020-08-06 13:27 ` Paul E. McKenney
2020-08-06 19:03 ` Thomas Gleixner
2020-08-06 20:39 ` Paul E. McKenney
2020-08-06 18:58 ` Thomas Gleixner
2020-08-06 9:34 ` Thomas Gleixner
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