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[ Upstream commitb7ca5743a2] It was reported that in 6.12, smpboot_create_threads() was taking much longer then in 6.6. I narrowed down the call path to: smpboot_create_threads() -> kthread_create_on_cpu() -> kthread_bind() -> __kthread_bind_mask() ->wait_task_inactive() Where in wait_task_inactive() we were regularly hitting the queued case, which sets a 1 tick timeout, which when called multiple times in a row, accumulates quickly into a long delay. I noticed disabling the DELAY_DEQUEUE sched feature recovered the performance, and it seems the newly create tasks are usually sched_delayed and left on the runqueue. So in wait_task_inactive() when we see the task p->se.sched_delayed, manually dequeue the sched_delayed task with DEQUEUE_DELAYED, so we don't have to constantly wait a tick. Fixes:152e11f6df("sched/fair: Implement delayed dequeue") Reported-by: peter-yc.chang@mediatek.com Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: K Prateek Nayak <kprateek.nayak@amd.com> Link: https://lkml.kernel.org/r/20250429150736.3778580-1-jstultz@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>