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| author |   Paul E. McKenney <paulmck@kernel.org> | 2020-11-13 12:54:48 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2021-01-04 13:53:38 -0800 |
| commit | 8b5bd67cf6422b63ee100d76d8de8960ca2df7f0 (patch) | |
| tree | 9bc4242c2aa4cfaad727526339abf4ede5d15eb0 /include/linux/srcu.h | |
| parent | srcu: Provide internal interface to start a Tree SRCU grace period (diff) | |
| download | linux-dev-8b5bd67cf6422b63ee100d76d8de8960ca2df7f0.tar.xz linux-dev-8b5bd67cf6422b63ee100d76d8de8960ca2df7f0.zip | |
srcu: Provide polling interfaces for Tiny 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 e432cc92c73d..a0895bbf71ce 100644 --- a/include/linux/srcu.h +++ b/include/linux/srcu.h @@ -60,6 +60,9 @@ void cleanup_srcu_struct(struct srcu_struct *ssp); int __srcu_read_lock(struct srcu_struct *ssp) __acquires(ssp); void __srcu_read_unlock(struct srcu_struct *ssp, int idx) __releases(ssp); void synchronize_srcu(struct srcu_struct *ssp); +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); #ifdef CONFIG_DEBUG_LOCK_ALLOC |