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Date:   Thu, 20 Oct 2022 01:15:01 +0100
From:   Qais Yousef <qyousef@layalina.io>
To:     John Stultz <jstultz@google.com>
Cc:     Alexander Gordeev <agordeev@linux.ibm.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Connor O'Brien <connoro@google.com>,
        John Dias <joaodias@google.com>, Rick Yiu <rickyiu@google.com>,
        John Kacur <jkacur@redhat.com>,
        Qais Yousef <qais.yousef@arm.com>,
        Chris Redpath <chris.redpath@arm.com>,
        Abhijeet Dharmapurikar <adharmap@quicinc.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Juri Lelli <juri.lelli@redhat.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Thomas Gleixner <tglx@linutronix.de>, kernel-team@android.com,
        "J . Avila" <elavila@google.com>
Subject: Re: [PATCH RFC v4 2/3] sched: Avoid placing RT threads on cores
 handling long softirqs
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On 10/19/22 15:09, John Stultz wrote:

> I fret there are some edge cases where on the target cpu softirqs
> might be pending but ksoftirqd isn't running yet maybe due to a
> lowish-prio rt task - such that the cpu could still be considered a
> good target. But this seems a bit of a stretch.

Could using ksoftirqd_running() instead help with robustness here?


Cheers

--
Qais Yousef