diff options
| author | Paul E. McKenney <paulmck@kernel.org> | 2020-11-13 17:31:55 -0800 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@gmail.com> | 2020-12-10 18:28:28 -0500 |
| commit | d61d8760d1142bdaf250e656892f341a1fb18dcd (patch) | |
| tree | 87e76cb51bc282106c1cc6328d6b9f615a3926db /include/linux/srcu.h | |
| parent | 763fee19acc3a40c6a9910066fcd9160179de455 (diff) | |
srcu: Provide polling interfaces for Tree SRCU grace periods
There is a need for a polling interface for SRCU grace
periods, so this commit supplies get_state_synchronize_srcu(),
start_poll_synchronize_srcu(), and poll_state_synchronize_srcu() for this
purpose. The first can be used if future grace periods are inevitable
(perhaps due to a later call_srcu() invocation), the second if future
grace periods might not otherwise happen, and the third to check if a
grace period has elapsed since the corresponding call to either of the
first two.
As with get_state_synchronize_rcu() and cond_synchronize_rcu(),
the return value from either get_state_synchronize_srcu() or
start_poll_synchronize_srcu() must be passed in to a later call to
poll_state_synchronize_srcu().
Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/
Reported-by: Kent Overstreet <kent.overstreet@gmail.com>
[ paulmck: Add EXPORT_SYMBOL_GPL() per kernel test robot feedback. ]
[ paulmck: Apply feedback from Neeraj Upadhyay. ]
Link: https://lore.kernel.org/lkml/20201117004017.GA7444@paulmck-ThinkPad-P72/
Reviewed-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'include/linux/srcu.h')
| -rw-r--r-- | include/linux/srcu.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/srcu.h b/include/linux/srcu.h index 67135d4a8a30..f55d5e5640ea 100644 --- a/include/linux/srcu.h +++ b/include/linux/srcu.h @@ -73,6 +73,9 @@ void _cleanup_srcu_struct(struct srcu_struct *sp, bool quiesced); int __srcu_read_lock(struct srcu_struct *sp) __acquires(sp); void __srcu_read_unlock(struct srcu_struct *sp, int idx) __releases(sp); void synchronize_srcu(struct srcu_struct *sp); +unsigned long get_state_synchronize_srcu(struct srcu_struct *ssp); +unsigned long start_poll_synchronize_srcu(struct srcu_struct *ssp); +bool poll_state_synchronize_srcu(struct srcu_struct *ssp, unsigned long cookie); /** * cleanup_srcu_struct - deconstruct a sleep-RCU structure |