From: Peter Zijlstra <peterz@infradead.org>
To: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: John Stultz <jstultz@google.com>,
mingo@kernel.org, juri.lelli@redhat.com,
vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de,
vschneid@redhat.com, linux-kernel@vger.kernel.org,
wangtao554@huawei.com, quzicheng@huawei.com, dsmythies@telus.net,
shubhang@os.amperecomputing.com,
Suleiman Souhlal <suleiman@google.com>
Subject: Re: [PATCH v2 1/7] sched/fair: Fix zero_vruntime tracking
Date: Mon, 30 Mar 2026 16:40:05 +0200 [thread overview]
Message-ID: <20260330144005.GP3738786@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <73dab51a-650f-4c82-9e73-13236b2a26c2@amd.com>
On Mon, Mar 30, 2026 at 08:07:06PM +0530, K Prateek Nayak wrote:
> Hello Peter,
>
> On 3/30/2026 3:40 PM, Peter Zijlstra wrote:
> > This means, that if the two tasks playing leapfrog can reach the
> > critical speed to reach the overflow point inside one tick's worth of
> > time, we're up a creek.
> >
> > If this is indeed the case, then the below should cure things.
>
> I have been running with this for four hours now and haven't seen
> any splats or crashes on my setup. I could reliably trigger the
> warning from __sum_w_vruntime_add() within an hour previously so
> it is safe to say I was hitting exactly this.
>
> Feel free to include:
>
> Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Ha!, excellent. Thanks!
next prev parent reply other threads:[~2026-03-30 14:40 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-19 7:58 [PATCH v2 0/7] sched: Various reweight_entity() fixes Peter Zijlstra
2026-02-19 7:58 ` [PATCH v2 1/7] sched/fair: Fix zero_vruntime tracking Peter Zijlstra
2026-02-23 10:56 ` Vincent Guittot
2026-02-23 13:09 ` Dietmar Eggemann
2026-02-23 14:15 ` Peter Zijlstra
2026-02-24 8:53 ` Dietmar Eggemann
2026-02-24 9:02 ` Peter Zijlstra
2026-03-28 5:44 ` John Stultz
2026-03-28 17:04 ` Steven Rostedt
2026-03-30 17:58 ` John Stultz
2026-03-30 18:27 ` Steven Rostedt
2026-03-30 9:43 ` Peter Zijlstra
2026-03-30 17:49 ` John Stultz
2026-03-30 10:10 ` Peter Zijlstra
2026-03-30 14:37 ` K Prateek Nayak
2026-03-30 14:40 ` Peter Zijlstra [this message]
2026-03-30 15:50 ` K Prateek Nayak
2026-03-30 19:11 ` Peter Zijlstra
2026-03-31 0:38 ` K Prateek Nayak
2026-03-31 4:58 ` K Prateek Nayak
2026-03-31 7:08 ` Peter Zijlstra
2026-03-31 7:14 ` Peter Zijlstra
2026-03-31 8:49 ` K Prateek Nayak
2026-03-31 9:29 ` Peter Zijlstra
2026-03-31 12:20 ` Peter Zijlstra
2026-03-31 16:14 ` Peter Zijlstra
2026-03-31 17:02 ` K Prateek Nayak
2026-03-31 22:40 ` John Stultz
2026-03-30 19:40 ` John Stultz
2026-03-30 19:43 ` Peter Zijlstra
2026-03-30 21:45 ` John Stultz
2026-02-19 7:58 ` [PATCH v2 2/7] sched/fair: Only set slice protection at pick time Peter Zijlstra
2026-02-19 7:58 ` [PATCH v2 3/7] sched/eevdf: Update se->vprot in reweight_entity() Peter Zijlstra
2026-02-19 7:58 ` [PATCH v2 4/7] sched/fair: Fix lag clamp Peter Zijlstra
2026-02-23 10:23 ` Dietmar Eggemann
2026-02-23 10:57 ` Vincent Guittot
2026-02-19 7:58 ` [PATCH v2 5/7] sched/fair: Increase weight bits for avg_vruntime Peter Zijlstra
2026-02-23 10:56 ` Vincent Guittot
2026-02-23 11:51 ` Peter Zijlstra
2026-02-23 12:36 ` Peter Zijlstra
2026-02-23 13:06 ` Vincent Guittot
2026-03-30 7:55 ` K Prateek Nayak
2026-03-30 9:27 ` Peter Zijlstra
2026-04-02 5:28 ` K Prateek Nayak
2026-04-02 10:22 ` Peter Zijlstra
2026-04-02 10:56 ` K Prateek Nayak
2026-04-03 4:02 ` K Prateek Nayak
2026-04-07 12:00 ` Peter Zijlstra
2026-04-07 13:42 ` [tip: sched/core] sched/fair: Avoid overflow in enqueue_entity() tip-bot2 for K Prateek Nayak
2026-02-19 7:58 ` [PATCH v2 6/7] sched/fair: Revert 6d71a9c61604 ("sched/fair: Fix EEVDF entity placement bug causing scheduling lag") Peter Zijlstra
2026-02-23 10:57 ` Vincent Guittot
2026-03-24 10:01 ` William Montaz
2026-04-07 13:45 ` Peter Zijlstra
2026-04-15 21:10 ` [PATCH 6.18] " John Stultz
2026-02-19 7:58 ` [PATCH v2 7/7] sched/fair: Use full weight to __calc_delta() Peter Zijlstra
2026-02-23 10:57 ` Vincent Guittot
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