diff options
| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2016-12-18 13:31:02 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-01-23 11:37:13 -0800 |
| commit | 09e2db37ec6d22bc27e2ba94ab4889541567f52e (patch) | |
| tree | 13e2304bed14a35b748222c0d170848c835dc0ce /kernel/rcu/tree_exp.h | |
| parent | 630c7ed9ca0608912fa7c8591d05dfc8742dc9e6 (diff) | |
rcu: Add comment headers to expedited-grace-period counter functions
These functions (rcu_exp_gp_seq_start(), rcu_exp_gp_seq_end(),
rcu_exp_gp_seq_snap(), and rcu_exp_gp_seq_done() seemed too obvious
to comment when written, but not so much when being documented.
This commit therefore adds header comments to each of them.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Diffstat (limited to 'kernel/rcu/tree_exp.h')
| -rw-r--r-- | kernel/rcu/tree_exp.h | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index e59e1849b89a..303df97bbfc5 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -20,16 +20,26 @@ * Authors: Paul E. McKenney <paulmck@linux.vnet.ibm.com> */ -/* Wrapper functions for expedited grace periods. */ +/* + * Record the start of an expedited grace period. + */ static void rcu_exp_gp_seq_start(struct rcu_state *rsp) { rcu_seq_start(&rsp->expedited_sequence); } + +/* + * Record the end of an expedited grace period. + */ static void rcu_exp_gp_seq_end(struct rcu_state *rsp) { rcu_seq_end(&rsp->expedited_sequence); smp_mb(); /* Ensure that consecutive grace periods serialize. */ } + +/* + * Take a snapshot of the expedited-grace-period counter. + */ static unsigned long rcu_exp_gp_seq_snap(struct rcu_state *rsp) { unsigned long s; @@ -39,6 +49,12 @@ static unsigned long rcu_exp_gp_seq_snap(struct rcu_state *rsp) trace_rcu_exp_grace_period(rsp->name, s, TPS("snap")); return s; } + +/* + * Given a counter snapshot from rcu_exp_gp_seq_snap(), return true + * if a full expedited grace period has elapsed since that snapshot + * was taken. + */ static bool rcu_exp_gp_seq_done(struct rcu_state *rsp, unsigned long s) { return rcu_seq_done(&rsp->expedited_sequence, s); |