diff options
| author | Paul E. McKenney <paulmck@kernel.org> | 2022-08-02 17:04:54 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2022-08-31 05:08:08 -0700 |
| commit | 76ea364161e72b1878126edf8d507d2a62fb47b0 (patch) | |
| tree | e8dc7f2d60fc85c8455c12ae8040c927d3efe693 /include | |
| parent | f4754ad2922e5a2b08c8aecf33d1ec03d7219fb4 (diff) | |
rcu: Add full-sized polling for start_poll()
The start_poll_synchronize_rcu() API compresses 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 next member of the full-state RCU
grace-period polling API, namely the start_poll_synchronize_rcu_full()
function. This uses up to three times the storage (rcu_gp_oldstate
structure instead of unsigned long), but is guaranteed not to miss
grace periods.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/rcutiny.h | 6 | ||||
| -rw-r--r-- | include/linux/rcutree.h | 1 |
2 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index 6e299955c4e9..6bc30e46a819 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -26,6 +26,12 @@ static inline void get_state_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp) } unsigned long start_poll_synchronize_rcu(void); + +static inline void start_poll_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp) +{ + rgosp->rgos_norm = start_poll_synchronize_rcu(); +} + bool poll_state_synchronize_rcu(unsigned long oldstate); static inline bool poll_state_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp) diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index 7b769f1b417a..8f2e0f0b26f6 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -52,6 +52,7 @@ void cond_synchronize_rcu_expedited(unsigned long oldstate); unsigned long get_state_synchronize_rcu(void); void get_state_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp); unsigned long start_poll_synchronize_rcu(void); +void start_poll_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp); bool poll_state_synchronize_rcu(unsigned long oldstate); bool poll_state_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp); void cond_synchronize_rcu(unsigned long oldstate); |