diff options
| author | Paul E. McKenney <paulmck@kernel.org> | 2022-08-04 13:46:05 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2022-08-31 05:08:08 -0700 |
| commit | b6fe4917ae4353b397079902cb024ae01f20dfb2 (patch) | |
| tree | ceacaaa87ca37baffd05550bb0090c6859878287 /include/linux | |
| parent | f21e014345e0abf11fdc2e59fb6eb6d6aa6ae4eb (diff) | |
rcu: Add full-sized polling for cond_sync_full()
The cond_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 yet another member of the full-state RCU
grace-period polling API, which is the cond_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.
[ paulmck: Apply feedback from kernel test robot and Julia Lawall. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/rcutiny.h | 5 | ||||
| -rw-r--r-- | include/linux/rcutree.h | 1 |
2 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index 653e35777a99..3bee97f76bf4 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -44,6 +44,11 @@ static inline void cond_synchronize_rcu(unsigned long oldstate) might_sleep(); } +static inline void cond_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp) +{ + cond_synchronize_rcu(rgosp->rgos_norm); +} + static inline unsigned long start_poll_synchronize_rcu_expedited(void) { return start_poll_synchronize_rcu(); diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index 7151fd861736..1b44288c027d 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -57,6 +57,7 @@ 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); +void cond_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp); bool rcu_is_idle_cpu(int cpu); |