Re: [PATCH 0/8] sched: Fix hot-unplug regressions

[Peter Zijlstra]

On Sat, Jan 16, 2021 at 12:30:33PM +0100, Peter Zijlstra wrote:
> Hi,
> 
> These patches (no longer 4), seems to fix all the hotplug regressions as per
> nearly a 100 18*SRCU-P runs over-night.
> 
> I did clean up the patches, so possibly I wrecked it again. I've started new
> runs and will again leave them running over-night.

Hurph... I've got one splat from this version, one I've not seen before:

[   68.712848] Dying CPU not properly vacated!
...
[   68.744448] CPU1 enqueued tasks (2 total):
[   68.745018]  pid: 14, name: rcu_preempt
[   68.745557]  pid: 18, name: migration/1

Paul, rcu_preempt, is from rcu_spawn_gp_kthread(), right? Afaict that
doesn't even have affinity.. /me wonders HTH that ended up on the
runqueue so late.