rcu_sync_enter() is an rcu_sync API used by updaters which forces RCU readers (e.g. percpu-rwsem) to take a slow-path during an update. It does this by setting the gp_state of the rcu_sync object to GP_ENTER (i.e. > 0). In this state, readers will take a "slow path", such as having percpu-rwsem readers wait on a semaphore rather than just incrementing a reader count. When the updater has completed their work, they must invoke rcu_sync_exit() to signal to readers that they may again take their fastpaths. rcu_sync_enter() currently has a comment that stipulates that a later call to rcu_sync_exit() (by an updater) will re-enable reader "slowpaths". This patch corrects the comment to properly reflect that rcu_sync_exit() re-enables reader fastpaths. Signed-off-by: David Vernet <void@xxxxxxxxxxxxx> --- kernel/rcu/sync.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/rcu/sync.c b/kernel/rcu/sync.c index 33d896d85902..5cefc702158f 100644 --- a/kernel/rcu/sync.c +++ b/kernel/rcu/sync.c @@ -111,7 +111,7 @@ static void rcu_sync_func(struct rcu_head *rhp) * a slowpath during the update. After this function returns, all * subsequent calls to rcu_sync_is_idle() will return false, which * tells readers to stay off their fastpaths. A later call to - * rcu_sync_exit() re-enables reader slowpaths. + * rcu_sync_exit() re-enables reader fastpaths. * * When called in isolation, rcu_sync_enter() must wait for a grace * period, however, closely spaced calls to rcu_sync_enter() can -- 2.30.2
