tree 1be0de7afced46cfca629dcbfc1807280c50bb13
parent 27d50c7eeb0f03c3d3ca72aac4d2dd487ca1f3f0
author Thomas Gleixner <tglx@linutronix.de> 1456998730 +0100
committer Thomas Gleixner <tglx@linutronix.de> 1456998730 +0100

cpu/hotplug: Plug death reporting race

Paul noticed that the conversion of the death reporting introduced a race
where the outgoing cpu might be delayed after waking the controll processor,
so it might not be able to call rcu_report_dead() before being physically
removed, leading to RCU stalls.

We cant call complete after rcu_report_dead(), so instead of going back to
busy polling, simply issue a function call to do the completion.

Fixes: 27d50c7eeb0f "rcu: Make CPU_DYING_IDLE an explicit call"
Reported-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20160302201127.GA23440@linux.vnet.ibm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>