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From:   Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     linux-kernel@vger.kernel.org, Ben Segall <bsegall@google.com>,
        Daniel Bristot de Oliveira <bristot@redhat.com>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Ingo Molnar <mingo@redhat.com>,
        Juri Lelli <juri.lelli@redhat.com>,
        Mel Gorman <mgorman@suse.de>,
        Steven Rostedt <rostedt@goodmis.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Valentin Schneider <vschneid@redhat.com>,
        Vincent Guittot <vincent.guittot@linaro.org>
Subject: Re: [PATCH] sched: Consider task_struct::saved_state in
 wait_task_inactive().
Message-ID: <Y/eaGdGD0sOAXWW+@linutronix.de>
References: <Y++UzubyNavLKFDP@linutronix.de>
 <Y/YaTojZ1stY2fAO@hirez.programming.kicks-ass.net>
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On 2023-02-22 14:36:14 [+0100], Peter Zijlstra wrote:
> Which if the very few wait_task_inactive() users requires this?

ptrace is the remaining (known) one (just verified on v6.2-rt3).
ptrace_check_attach() waits for the child which blocks on tasklist_lock.

tglx argued that wait_task_inactive() should work regardless of the
task, that is being waited for, blocks on a sleeping lock.

Sebastian