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9f866dac94
Currently, rcu_cpu_starting() checks to see if the RCU core expects a quiescent state from the incoming CPU. However, the current interaction between RCU quiescent-state reporting and CPU-hotplug operations should mean that the incoming CPU never needs to report a quiescent state. First, the outgoing CPU reports a quiescent state if needed. Second, the race where the CPU is leaving just as RCU is initializing a new grace period is handled by an explicit check for this condition. Third, the CPU's leaf rcu_node structure's ->lock serializes these checks. This means that if rcu_cpu_starting() ever feels the need to report a quiescent state, then there is a bug somewhere in the CPU hotplug code or the RCU grace-period handling code. This commit therefore adds a WARN_ON_ONCE() to bring that bug to everyone's attention. Cc: Neeraj Upadhyay <neeraju@codeaurora.org> Suggested-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
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.. | ||
Kconfig | ||
Kconfig.debug | ||
Makefile | ||
rcu.h | ||
rcu_segcblist.c | ||
rcu_segcblist.h | ||
rcuscale.c | ||
rcutorture.c | ||
refscale.c | ||
srcutiny.c | ||
srcutree.c | ||
sync.c | ||
tasks.h | ||
tiny.c | ||
tree.c | ||
tree.h | ||
tree_exp.h | ||
tree_plugin.h | ||
tree_stall.h | ||
update.c |