From: "Paul E. McKenney" <paulmck@xxxxxxxxxx> The synchronize_rcu_tasks_trace() header comment incorrectly claims that any number of things delimit RCU Tasks Trace read-side critical sections, when in fact only rcu_read_lock_trace() and rcu_read_unlock_trace() do so. This commit therefore fixes this comment, and, while in the area, fixes a typo in the rcu_read_lock_trace() header comment. Reported-by: Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx> --- include/linux/rcupdate_trace.h | 4 ++-- kernel/rcu/tasks.h | 9 ++++----- 2 files changed, 6 insertions(+), 7 deletions(-) diff --git a/include/linux/rcupdate_trace.h b/include/linux/rcupdate_trace.h index 4c25a41..d9015aa 100644 --- a/include/linux/rcupdate_trace.h +++ b/include/linux/rcupdate_trace.h @@ -36,8 +36,8 @@ void rcu_read_unlock_trace_special(struct task_struct *t, int nesting); /** * rcu_read_lock_trace - mark beginning of RCU-trace read-side critical section * - * When synchronize_rcu_trace() is invoked by one task, then that task - * is guaranteed to block until all other tasks exit their read-side + * When synchronize_rcu_tasks_trace() is invoked by one task, then that + * task is guaranteed to block until all other tasks exit their read-side * critical sections. Similarly, if call_rcu_trace() is invoked on one * task while other tasks are within RCU read-side critical sections, * invocation of the corresponding RCU callback is deferred until after diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h index ce23f6c..a77298c 100644 --- a/kernel/rcu/tasks.h +++ b/kernel/rcu/tasks.h @@ -1118,11 +1118,10 @@ EXPORT_SYMBOL_GPL(call_rcu_tasks_trace); * synchronize_rcu_tasks_trace - wait for a trace rcu-tasks grace period * * Control will return to the caller some time after a trace rcu-tasks - * grace period has elapsed, in other words after all currently - * executing rcu-tasks read-side critical sections have elapsed. These - * read-side critical sections are delimited by calls to schedule(), - * cond_resched_tasks_rcu_qs(), userspace execution, and (in theory, - * anyway) cond_resched(). + * grace period has elapsed, in other words after all currently executing + * rcu-tasks read-side critical sections have elapsed. These read-side + * critical sections are delimited by calls to rcu_read_lock_trace() + * and rcu_read_unlock_trace(). * * This is a very specialized primitive, intended only for a few uses in * tracing and other situations requiring manipulation of function preambles -- 2.9.5
