Re: [PATCH v5 tip/core/rcu 15/16] rcu: Make RCU-tasks wait for idle tasks

From: Peter Zijlstra
Date: Wed Aug 13 2014 - 12:30:49 EST


On Wed, Aug 13, 2014 at 07:43:32AM -0700, Paul E. McKenney wrote:
> o drivers/acpi/acpi_pad.c, power_saving_thread().
>
> Looks like a kthread that does idle injection. Currently, RCU
> sees it as not a quiescent state. Would it kill these guys to
> put in a comment or two about what this is for???
>
> So adding rcu_idle_enter() and rcu_idle_exit() here might
> actually fix a bug, though it is not clear how long this thing
> actually runs. If only for a few milliseconds, no harm done.
>

> o drivers/thermal/intel_powerclamp.c, clamp_thread().
>
> Looks similar to power_saving_thread(), but for thermal control.
> Probably short term, shouldn't be a problem either way.
>

There's patches somewhere that make that go-away

https://lkml.org/lkml/2014/6/4/56

Jacob was going to look at that.

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