[0/9] SRCU updates for v6.3

Message

Paul E. McKenney Jan. 5, 2023, 12:28 a.m. UTC

Hello!

This series provides SRCU updates, perhaps most notably the addition
of a srcu_down_read() and srcu_up_read() that act like srcu_read_lock()
and srcu_read_unlock(), but which permit the srcu_up_read() to be invoked
from a different context than the srcu_down_read().

1.	Release early_srcu resources when no longer in use, courtesy
	of Zqiang.

2.	Delegate work to the boot cpu if using SRCU_SIZE_SMALL, courtesy
	of Pingfan Liu.

3.	Fix a misspelling in comment, courtesy of Pingfan Liu.

4.	Fix the comparision in srcu_invl_snp_seq(), courtesy of Pingfan
	Liu.

5.	Add srcu_down_read() and srcu_up_read().

6.	Add test code for semaphore-like SRCU readers.

7.	Remove needless rcu_seq_done() check while holding read lock,
	courtesy of Pingfan Liu.

8.	Yet more detail for srcu_readers_active_idx_check() comments.

9.	Update comment after the index flip.

						Thanx, Paul

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

 b/include/linux/srcu.h     |   45 ++++++++++++++++++++++
 b/include/linux/srcutree.h |    2 -
 b/kernel/rcu/srcutree.c    |    9 ++--
 b/kernel/rcu/update.c      |    1 
 kernel/rcu/srcutree.c      |   89 ++++++++++++++++++++++++++++++++-------------
 kernel/rcu/update.c        |    3 +
 6 files changed, 119 insertions(+), 30 deletions(-)