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| author | Paul E. McKenney <paulmck@kernel.org> | 2022-07-28 15:37:05 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2022-08-31 05:08:07 -0700 |
| commit | 91a967fd6934abc0c7e4b0d26728e38674278707 (patch) | |
| tree | f713b1173e8d3a19a68e645a5a8dc2b2f0eefbf7 /include/linux/rcupdate.h | |
| parent | 568035b01cfb107af8d2e4bd2fb9aea22cf5b868 (diff) | |
| download | linux-91a967fd6934abc0c7e4b0d26728e38674278707.tar.bz2 | |
rcu: Add full-sized polling for get_completed*() and poll_state*()
The get_completed_synchronize_rcu() and poll_state_synchronize_rcu()
APIs compress the combined expedited and normal grace-period states into a
single unsigned long, which conserves storage, but can miss grace periods
in certain cases involving overlapping normal and expedited grace periods.
Missing the occasional grace period is usually not a problem, but there
are use cases that care about each and every grace period.
This commit therefore adds the first members of the full-state RCU
grace-period polling API, namely the get_completed_synchronize_rcu_full()
and poll_state_synchronize_rcu_full() functions. These use up to three
times the storage (rcu_gp_oldstate structure instead of unsigned long),
but which are guaranteed not to miss grace periods, at least in situations
where the single-CPU grace-period optimization does not apply.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'include/linux/rcupdate.h')
| -rw-r--r-- | include/linux/rcupdate.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index f527f27e6438..faaa174dfb27 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -42,7 +42,10 @@ void call_rcu(struct rcu_head *head, rcu_callback_t func); void rcu_barrier_tasks(void); void rcu_barrier_tasks_rude(void); void synchronize_rcu(void); + +struct rcu_gp_oldstate; unsigned long get_completed_synchronize_rcu(void); +void get_completed_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp); #ifdef CONFIG_PREEMPT_RCU |