tree 23e5b8623c2c37bd8a4656c66266209872f80701
parent 5b61b0baa9e80289c53413e573befc5790a04ac7
author Paul E. McKenney <paulmck@linux.vnet.ibm.com> 1313890172 -0700
committer Paul E. McKenney <paulmck@linux.vnet.ibm.com> 1317271128 -0700

rcu: Remove rcu_needs_cpu_flush() to avoid false quiescent states

The purpose of rcu_needs_cpu_flush() was to iterate on pushing the
current grace period in order to help the current CPU enter dyntick-idle
mode.  However, this can result in failures if the CPU starts entering
dyntick-idle mode, but then backs out.  In this case, the call to
rcu_pending() from rcu_needs_cpu_flush() might end up announcing a
non-existing quiescent state.

This commit therefore removes rcu_needs_cpu_flush() in favor of letting
the dyntick-idle machinery at the end of the softirq handler push the
loop along via its call to rcu_pending().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>