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From: Vincent Guittot <vincent.guittot@linaro.org>
To: Odin Ugedal <odin@uged.al>
Cc: Sachin Sant <sachinp@linux.vnet.ibm.com>,
	Linux Next Mailing List <linux-next@vger.kernel.org>,
	linuxppc-dev@lists.ozlabs.org,
	open list <linux-kernel@vger.kernel.org>
Subject: Re: [powerpc][next-20210621] WARNING at kernel/sched/fair.c:3277 during boot
Date: Wed, 23 Jun 2021 15:55:47 +0200	[thread overview]
Message-ID: <CAKfTPtAev0VgCmK3AUyTCoVA38YmskpB98q0kTrbEPK6e=1dTA@mail.gmail.com> (raw)
In-Reply-To: <CAFpoUr3bHzrwvumw6R=2JVbKa_wmtT9cMf-mdDHxY0Png-N9Jw@mail.gmail.com>

On Wed, 23 Jun 2021 at 14:37, Odin Ugedal <odin@uged.al> wrote:
>
> ons. 23. jun. 2021 kl. 14:22 skrev Vincent Guittot <vincent.guittot@linaro.org>:
> >
> > In theory it should not because _sum should be always larger or equal
> > to _avg * divider. Otherwise, it means that we have something wrong
> > somewhere else
>
> Yeah, that might be the case. Still trying to wrap my head around
> this. I might be wrong, but isn't there a possibility
> that avg->period_contrib is increasing in PELTs accumulate_sum,
> without _sum is increasing. This makes the pelt divider increase,
> making the statement "_sum should be always larger or equal to _avg *"
> false? Or am I missing something obvious here?

The pelt value of sched_entity is synced with  cfs and its contrib
before being removed.
Then, we start to remove this load in update_cfs_rq_load_avg() before
calling __update_load_avg_cfs_rq so contrib should not have change and
we should be safe

>
> Still unable to reproduce what Sachin is reporting tho.
>
> Odin

  reply	other threads:[~2021-06-23 13:56 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-22  7:39 [powerpc][next-20210621] WARNING at kernel/sched/fair.c:3277 during boot Sachin Sant
2021-06-22  7:49 ` Vincent Guittot
2021-06-22 14:31   ` Vincent Guittot
2021-06-22 15:59     ` Sachin Sant
2021-06-23  7:19       ` Vincent Guittot
2021-06-23  7:58         ` Sachin Sant
2021-06-23 10:22           ` Sachin Sant
2021-06-23 12:08             ` Vincent Guittot
2021-06-23 12:18               ` Odin Ugedal
2021-06-23 12:22                 ` Vincent Guittot
2021-06-23 12:37                   ` Odin Ugedal
2021-06-23 13:55                     ` Vincent Guittot [this message]
2021-06-23 15:13                       ` Odin Ugedal
2021-06-23 15:25                         ` Vincent Guittot
2021-06-23 16:45               ` Sachin Sant
2021-06-23 16:55                 ` Vincent Guittot
2021-06-23 17:27                   ` Vincent Guittot
2021-06-23 17:37                     ` Odin Ugedal

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