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Thomas Gleixner authored
sched_setscheduler() and rt_mutex_setprio() invoke the run-queue balance callback after changing priorities or the scheduling class of a task. The run-queue for which the callback is invoked can be local or remote. That's not a problem for the regular rq::push_work which is serialized with a busy flag in the run-queue struct, but for the balance_push() work which is only valid to be invoked on the outgoing CPU that's wrong. It not only triggers the debug warning, but also leaves the per CPU variable push_work unprotected, which can result in double enqueues on the stop machine list. Remove the warning and validate that the function is invoked on the outgoing CPU. Fixes: ae792702 ("sched: Optimize finish_lock_switch()") Reported-by: Sebastian Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Segall <bsegall@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://lore.kernel.org/r/87zgt1hdw7.ffs@tglx
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