[0/7] Callback-offload (nocb) updates for v5.20

Message

Paul E. McKenney June 20, 2022, 10:44 p.m. UTC

Hello!

This series provides NOCB-CPU updates:

1.	Add/del rdp to iterate from rcuog itself, courtesy of Frederic
	Weisbecker.

2.	Invert rcu_state.barrier_mutex VS hotplug lock locking order,
	courtesy of Zqiang.

3.	Fix NOCB kthreads spawn failure with rcu_nocb_rdp_deoffload()
	direct call, courtesy of Zqiang.

4.	Add an option to offload all CPUs on boot, courtesy of Joel
	Fernandes.

5.	Add nocb_cb_kthread check to rcu_is_callbacks_kthread(), courtesy
	of Zqiang.

6.	Add option to opt rcuo kthreads out of RT priority, courtesy of
	"Uladzislau Rezki (Sony)".

7.	Avoid polling when my_rdp->nocb_head_rdp list is empty, courtesy
	of Zqiang.

						Thanx, Paul

------------------------------------------------------------------------

 b/Documentation/admin-guide/kernel-parameters.txt |    6 
 b/kernel/rcu/Kconfig                              |   13 ++
 b/kernel/rcu/tree.c                               |    4 
 b/kernel/rcu/tree.h                               |    1 
 b/kernel/rcu/tree_nocb.h                          |  138 +++++++++++-----------
 b/kernel/rcu/tree_plugin.h                        |   33 +++--
 kernel/rcu/Kconfig                                |   16 ++
 kernel/rcu/tree.c                                 |    6 
 kernel/rcu/tree.h                                 |    2 
 kernel/rcu/tree_nocb.h                            |  130 ++++++++++++++++----
 10 files changed, 236 insertions(+), 113 deletions(-)