Re: [PATCH RT 15/25] sched: migrate_enable: Use select_fallback_rq()

From: Sebastian Andrzej Siewior
Date: Mon Feb 24 2020 - 04:43:55 EST


On 2020-02-21 15:24:43 [-0600], zanussi@xxxxxxxxxx wrote:
> From: Scott Wood <swood@xxxxxxxxxx>
>
> v4.14.170-rt75-rc1 stable review patch.
> If anyone has any objections, please let me know.

This creates bug which is stuffed later via
sched: migrate_enable: Busy loop until the migration request is completed

So if apply this, please take the bug fix, too. This is Stevens queue
for reference:
|[PATCH RT 22/30] sched: migrate_enable: Use select_fallback_rq()
^^ bug introduced

|[PATCH RT 23/30] sched: Lazy migrate_disable processing
|[PATCH RT 24/30] sched: migrate_enable: Use stop_one_cpu_nowait()
|[PATCH RT 25/30] Revert "ARM: Initialize split page table locks for vector page"
|[PATCH RT 26/30] locking: Make spinlock_t and rwlock_t a RCU section on RT
|[PATCH RT 27/30] sched/core: migrate_enable() must access takedown_cpu_task on !HOTPLUG_CPU
|[PATCH RT 28/30] lib/smp_processor_id: Adjust check_preemption_disabled()
|[PATCH RT 29/30] sched: migrate_enable: Busy loop until the migration request is completed
^^ bug fixed

Sebastian