Re: [PATCH x86/entry: Force rcu_irq_enter() when in idle task

[Thomas Gleixner]

"Paul E. McKenney" <paulmck@xxxxxxxxxx> writes:
> On Fri, Jun 12, 2020 at 10:49:53AM -0700, Paul E. McKenney wrote:
>> I will therefore address this issue in a follow-on patch.
>
> I should add that -your- patch from yesterday did -not- cause this
> problem, in case that is of interest.

So I still can add it back and amend the changelog and comment:

Change the condition from !rcu_is_watching() to is_idle_task(current) ||
rcu_is_watching() which enforces that interrupts in the idle task
unconditionally invoke rcu_irq_enter() independent of the RCU state. For
most scenarios is_idle_task() would be sufficient but Task RCU needs it
according to Paul.

Thanks,

        tglx