From: Tejun Heo <tj@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
Valentin Schneider <vschneid@redhat.com>,
K Prateek Nayak <kprateek.nayak@amd.com>,
Kyle McMartin <jkkm@meta.com>
Subject: Re: [PATCH v2] sched/rt: Have RT_PUSH_IPI be default off for non PREEMPT_RT
Date: Fri, 15 May 2026 07:17:44 -1000 [thread overview]
Message-ID: <agdVODCkR8lPI535@slm.duckdns.org> (raw)
In-Reply-To: <20260515103740.25ccbed8@gandalf.local.home>
On Fri, May 15, 2026 at 10:37:40AM -0400, Steven Rostedt wrote:
...
> A live lock occurred on a workload that was doing heavy networking traffic
> on a large machine where the softirqs would run 500us out of 750us. And it
> would also be waking up RT tasks, causing the RT pull logic to be
> constantly executed.
nit: 500/750us is the synthetic repro. The actual case is 30-40% cpu util,
so substantially lower.
> Reported-by: Tejun Heo <tj@kernel.org>
> Closes: https://lore.kernel.org/all/20260506235716.2530720-1-tj@kernel.org/
> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Tested-by: Tejun Heo <tj@kernel.org>
Thanks.
--
tejun
next prev parent reply other threads:[~2026-05-15 17:17 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-15 14:37 [PATCH v2] sched/rt: Have RT_PUSH_IPI be default off for non PREEMPT_RT Steven Rostedt
2026-05-15 17:17 ` Tejun Heo [this message]
2026-05-15 18:38 ` Steven Rostedt
2026-05-15 18:47 ` Tejun Heo
2026-05-15 18:56 ` Steven Rostedt
2026-05-15 22:27 ` Tejun Heo
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