[RFC] rcu: Prevent expedite reporting within RCU read-side section

[Byungchul Park]

Hello Paul and RCU folks,

I am afraid I correctly understand and fix it. But I really wonder why
sync_rcu_exp_handler() reports the quiescent state even in the case that
current task is within a RCU read-side section. Do I miss something?

If I correctly understand it and you agree with it, I can add more logic
which make it more expedited by boosting current or making it urgent
when we fail to report the quiescent state on the IPI.

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