On Mon, 2020-02-24 at 10:43 +0100, Sebastian Andrzej Siewior wrote:

On 2020-02-21 15:24:43 [-0600], zanussi@kernel.org wrote:

quoted

From: Scott Wood <redacted>

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:

quoted

[PATCH RT 22/30] sched: migrate_enable: Use select_fallback_rq()

^^ bug introduced

Hmm, it seemed from the comment on the 4.19 series that it was '24/32
sched: migrate_enable: Use stop_one_cpu_nowait()' that required 'sched:
migrate_enable: Busy loop until the migration request is
completed' as a bug fix.

  https://lore.kernel.org/linux-rt-users/20200122083130.kuu3yppckhyjrr4u@linutronix.de/#t (local)

I didn't take the stop_one_cpu_nowait() one, so didn't take the busy
loop one either.

Thanks,

Tom

quoted

[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