From: Dietmar Eggemann <dietmar.eggemann@arm.com>
To: Heiner Kallweit <hkallweit1@gmail.com>,
Vincent Guittot <vincent.guittot@linaro.org>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: Problem with commit 31e77c93e432 "sched/fair: Update blocked load when newly idle"
Date: Wed, 28 Mar 2018 12:37:32 +0200 [thread overview]
Message-ID: <6b151c56-9ead-7bbe-d1b7-b0e6d69c0d7f@arm.com> (raw)
In-Reply-To: <c5daea3c-0834-1629-3e38-3db5130eb32f@gmail.com>
Hi,
On 03/24/2018 01:47 PM, Heiner Kallweit wrote:
> Am 24.03.2018 um 07:46 schrieb Vincent Guittot:
>> Hi Heiner,
>>
>> Le Friday 23 Mar 2018 à 22:28:09 (+0100), Heiner Kallweit a écrit :
>>> Recently I started to get the following problems with linux-next:
>>>
>>> - When working via Putty/SSH on the system the console frequently freezes
>>> for few seconds. Sometimes only opening a second console makes the
>>> first one react again.
>>>
>>> - I get "INFO: rcu_sched detected stalls on CPUs/tasks:" warnings as
>>> described in [1].
>>>
I can't catch this issue on my Juno r0 (arm64 big.Little).
root@juno:~# uname -r
4.16.0-rc4-00198-g31e77c93e432
I'm using openssh-client and openssh-server though.
>>> Bisecting the issue resulted in:
>>>
>>> 31e77c93e432dec79c7d90b888bbfc3652592741 is the first bad commit
>>> commit 31e77c93e432dec79c7d90b888bbfc3652592741
>>> Author: Vincent Guittot <vincent.guittot@linaro.org>
>>> Date: Wed Feb 14 16:26:46 2018 +0100
>>>
>>> sched/fair: Update blocked load when newly idle
>>>
>>> When NEWLY_IDLE load balance is not triggered, we might need to update the
>>> blocked load anyway. We can kick an ilb so an idle CPU will take care of
>>> updating blocked load or we can try to update them locally before entering
>>> idle. In the latter case, we reuse part of the nohz_idle_balance.
>>>
>>> After reversing this commit at least the issue with the freezing console
>>> is gone. The second one appeared only sporadically, I still have to see
>>> whether it pops up again.
[...]
next prev parent reply other threads:[~2018-03-28 10:37 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-23 21:28 Problem with commit 31e77c93e432 "sched/fair: Update blocked load when newly idle" Heiner Kallweit
2018-03-24 6:46 ` Vincent Guittot
2018-03-24 12:47 ` Heiner Kallweit
2018-03-28 10:37 ` Dietmar Eggemann [this message]
2018-03-28 14:01 ` Vincent Guittot
2018-03-29 7:41 ` Vincent Guittot
2018-03-29 17:40 ` Heiner Kallweit
2018-03-30 6:50 ` Vincent Guittot
2018-03-30 8:37 ` Heiner Kallweit
2018-04-06 16:03 ` Vincent Guittot
2018-04-06 19:53 ` Heiner Kallweit
2018-04-09 17:33 ` Heiner Kallweit
2018-04-11 17:00 ` Vincent Guittot
2018-04-11 20:35 ` Heiner Kallweit
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