From: Marc Zyngier <maz@kernel.org>
To: Valentin Schneider <valentin.schneider@arm.com>,
Vladimir Oltean <olteanv@gmail.com>
Cc: paulmck@kernel.org, Robin Murphy <robin.murphy@arm.com>,
Alison Wang <alison.wang@nxp.com>,
linux-kernel@vger.kernel.org, leoyang.li@nxp.com,
vladimir.oltean@nxp.com, will@kernel.org,
catalin.marinas@arm.com,
Kurt Kanzenbach <kurt.kanzenbach@linutronix.de>,
Thomas Gleixner <tglx@linutronix.de>,
mw@semihalf.com, Anna-Maria Gleixner <anna-maria@linutronix.de>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [RFC PATCH] arm64: defconfig: Disable fine-grained task level IRQ time accounting
Date: Mon, 03 Aug 2020 14:24:39 +0100 [thread overview]
Message-ID: <34b6cca5355f9e709554892261ac4b0c@kernel.org> (raw)
In-Reply-To: <jhjime0hrvw.mognet@arm.com>
On 2020-08-03 12:48, Valentin Schneider wrote:
> On 03/08/20 12:38, Vladimir Oltean wrote:
>> On Mon, Aug 03, 2020 at 10:51:32AM +0100, Robin Murphy wrote:
>>>
>>> Having glanced across another thread that mentions IRQ accounting
>>> recently[1], I wonder if the underlying bug here might have something
>>> do to
>>> with the stuff that Marc's trying to clean up.
>>>
>>> Robin.
>>>
>>> [1]
>>> https://lore.kernel.org/linux-arm-kernel/20200624195811.435857-16-maz@kernel.org/
>>
>> Thanks Robin. I've applied Marc's "[PATCH v2 00/17] arm/arm64: Turning
>> IPIs into normal interrupts" series and the LS1028A I'm debugging
>> hangs
>> in absolutely the same way.
>>
>
> I'm not too surprised by that, wrt accounting this mostly changes where
> the
> stores go to and barely shuffles when they happen (slightly earlier on
> the
> IPI handling path).
Indeed. This series is just a "let's make things be the way they should
be",
and isn't really fixing any bug. It actually may introduce a couple...
> FWIW I've had 'stress-ng --hrtimers 1' running on my Juno and eMAG for
> ~15
> minutes and haven't had a splat yet.
I've started a couple of VMs with that workload too. 400K irq/s on an
8 vcpu guest, nothing to report so far.
But removing IRQ_TIME_ACCOUNTING from defconfig is a resounding "no
way!".
It looks like we have a bug, and it should be squashed, not glanced
over.
M.
--
Jazz is not dead. It just smells funny...
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WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: Valentin Schneider <valentin.schneider@arm.com>,
Vladimir Oltean <olteanv@gmail.com>
Cc: Robin Murphy <robin.murphy@arm.com>,
Kurt Kanzenbach <kurt.kanzenbach@linutronix.de>,
paulmck@kernel.org,
Anna-Maria Gleixner <anna-maria@linutronix.de>,
catalin.marinas@arm.com, Alison Wang <alison.wang@nxp.com>,
linux-kernel@vger.kernel.org, leoyang.li@nxp.com,
vladimir.oltean@nxp.com, Thomas Gleixner <tglx@linutronix.de>,
mw@semihalf.com, will@kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [RFC PATCH] arm64: defconfig: Disable fine-grained task level IRQ time accounting
Date: Mon, 03 Aug 2020 14:24:39 +0100 [thread overview]
Message-ID: <34b6cca5355f9e709554892261ac4b0c@kernel.org> (raw)
In-Reply-To: <jhjime0hrvw.mognet@arm.com>
On 2020-08-03 12:48, Valentin Schneider wrote:
> On 03/08/20 12:38, Vladimir Oltean wrote:
>> On Mon, Aug 03, 2020 at 10:51:32AM +0100, Robin Murphy wrote:
>>>
>>> Having glanced across another thread that mentions IRQ accounting
>>> recently[1], I wonder if the underlying bug here might have something
>>> do to
>>> with the stuff that Marc's trying to clean up.
>>>
>>> Robin.
>>>
>>> [1]
>>> https://lore.kernel.org/linux-arm-kernel/20200624195811.435857-16-maz@kernel.org/
>>
>> Thanks Robin. I've applied Marc's "[PATCH v2 00/17] arm/arm64: Turning
>> IPIs into normal interrupts" series and the LS1028A I'm debugging
>> hangs
>> in absolutely the same way.
>>
>
> I'm not too surprised by that, wrt accounting this mostly changes where
> the
> stores go to and barely shuffles when they happen (slightly earlier on
> the
> IPI handling path).
Indeed. This series is just a "let's make things be the way they should
be",
and isn't really fixing any bug. It actually may introduce a couple...
> FWIW I've had 'stress-ng --hrtimers 1' running on my Juno and eMAG for
> ~15
> minutes and haven't had a splat yet.
I've started a couple of VMs with that workload too. 400K irq/s on an
8 vcpu guest, nothing to report so far.
But removing IRQ_TIME_ACCOUNTING from defconfig is a resounding "no
way!".
It looks like we have a bug, and it should be squashed, not glanced
over.
M.
--
Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2020-08-03 13:26 UTC|newest]
Thread overview: 62+ 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 3:39 ` Alison Wang
2020-07-29 8:40 ` Kurt Kanzenbach
2020-07-29 8:40 ` Kurt Kanzenbach
2020-07-29 8:50 ` [EXT] " Alison Wang
2020-07-29 8:50 ` Alison Wang
2020-07-29 9:49 ` Vladimir Oltean
2020-07-29 9:49 ` Vladimir Oltean
2020-07-30 7:23 ` Kurt Kanzenbach
2020-07-30 7:23 ` Kurt Kanzenbach
2020-07-30 8:22 ` Vladimir Oltean
2020-07-30 8:22 ` Vladimir Oltean
2020-08-03 8:04 ` Kurt Kanzenbach
2020-08-03 8:04 ` Kurt Kanzenbach
2020-08-03 8:16 ` Vladimir Oltean
2020-08-03 8:16 ` Vladimir Oltean
2020-08-03 9:51 ` Robin Murphy
2020-08-03 9:51 ` Robin Murphy
2020-08-03 11:38 ` Vladimir Oltean
2020-08-03 11:38 ` Vladimir Oltean
2020-08-03 11:48 ` Valentin Schneider
2020-08-03 11:48 ` Valentin Schneider
2020-08-03 13:24 ` Marc Zyngier [this message]
2020-08-03 13:24 ` Marc Zyngier
2020-08-03 10:02 ` Thomas Gleixner
2020-08-03 10:02 ` Thomas Gleixner
2020-08-03 10:49 ` Thomas Gleixner
2020-08-03 10:49 ` Thomas Gleixner
2020-08-03 11:41 ` Vladimir Oltean
2020-08-03 11:41 ` Vladimir Oltean
2020-08-03 15:13 ` Thomas Gleixner
2020-08-03 15:13 ` Thomas Gleixner
2020-08-03 15:47 ` Valentin Schneider
2020-08-03 15:47 ` Valentin Schneider
2020-08-03 16:14 ` Vladimir Oltean
2020-08-03 16:14 ` Vladimir Oltean
2020-08-03 19:22 ` Thomas Gleixner
2020-08-03 19:22 ` Thomas Gleixner
2020-08-03 23:59 ` Valentin Schneider
2020-08-03 23:59 ` Valentin Schneider
2020-08-05 8:50 ` Dietmar Eggemann
2020-08-05 8:50 ` Dietmar Eggemann
2020-08-05 13:40 ` peterz
2020-08-05 13:40 ` peterz
2020-08-05 13:56 ` Valentin Schneider
2020-08-05 13:56 ` Valentin Schneider
2020-08-05 15:31 ` peterz
2020-08-05 15:31 ` peterz
2020-08-06 9:41 ` Thomas Gleixner
2020-08-06 9:41 ` Thomas Gleixner
2020-08-06 11:45 ` peterz
2020-08-06 11:45 ` peterz
2020-08-06 13:27 ` Paul E. McKenney
2020-08-06 13:27 ` Paul E. McKenney
2020-08-06 19:03 ` Thomas Gleixner
2020-08-06 19:03 ` Thomas Gleixner
2020-08-06 20:39 ` Paul E. McKenney
2020-08-06 20:39 ` Paul E. McKenney
2020-08-06 18:58 ` Thomas Gleixner
2020-08-06 18:58 ` Thomas Gleixner
2020-08-06 9:34 ` Thomas Gleixner
2020-08-06 9:34 ` Thomas Gleixner
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