rcu/nocb: Don't invoke local rcu core on callback overload from nocb kthread

rcu_core() tries to ensure that its self-invocation in case of callbacks
overload only happen in softirq/rcuc mode. Indeed it doesn't make sense
to trigger local RCU core from nocb_cb kthread since it can execute
on a CPU different from the target rdp. Also in case of overload, the
nocb_cb kthread simply iterates a new loop of callbacks processing.

However the "offloaded" check that aims at preventing misplaced
rcu_core() invocations is wrong. First of all that state is volatile
and second: softirq/rcuc can execute while the target rdp is offloaded.
As a result rcu_core() can be invoked on the wrong CPU while in the
process of (de-)offloading.

Fix that with moving the rcu_core() self-invocation to rcu_core() itself,
irrespective of the rdp offloaded state.

Tested-by: Valentin Schneider <[email protected]>
Tested-by: Sebastian Andrzej Siewior <[email protected]>
Signed-off-by: Frederic Weisbecker <[email protected]>
Cc: Valentin Schneider <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Sebastian Andrzej Siewior <[email protected]>
Cc: Josh Triplett <[email protected]>
Cc: Joel Fernandes <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: Neeraj Upadhyay <[email protected]>
Cc: Uladzislau Rezki <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>

0 files changed, 0 insertions, 0 deletions