Re: [PATCH] rcu: Fix various typos in comments

Paul E. McKenney
2021-03-23T05:37:13Z

On Tue, Mar 23, 2021 at 08:26:14AM +0530, Bhaskar Chowdhury wrote:
> On 00:02 Tue 23 Mar 2021, Ingo Molnar wrote:
> >
> > Hi Paul,
> >
> > Was working on automation to make it a bit more straightforward to fix
> > typos within comments (which we tend to reintroduce during
> > development), and here are the ones it found in the RCU code.
> >
> > Thanks,
> >
> > Ingo
> >
> > =========>
> > From: Ingo Molnar <mingo@kernel.org>
> > Date: Mon, 22 Mar 2021 23:57:26 +0100
> > Subject: [PATCH] rcu: Fix various typos in comments
> >
> > Fix ~12 single-word typos in RCU code comments.
> >
> > Signed-off-by: Ingo Molnar <mingo@kernel.org>
> > Cc: Paul E. McKenney <paulmck@kernel.org>
> > Cc: linux-kernel@vger.kernel.org
> > ---
> > kernel/rcu/srcutree.c | 4 ++--
> > kernel/rcu/sync.c | 2 +-
> > kernel/rcu/tasks.h | 8 ++++----
> > kernel/rcu/tree.c | 4 ++--
> > kernel/rcu/tree.h | 2 +-
> > kernel/rcu/tree_plugin.h | 2 +-
> > tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/locks.h | 2 +-
> > 7 files changed, 12 insertions(+), 12 deletions(-)
> >
> > diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
> > index e26547b34ad3..036ff5499ad5 100644
> > --- a/kernel/rcu/srcutree.c
> > +++ b/kernel/rcu/srcutree.c
> > @@ -777,9 +777,9 @@ static bool srcu_might_be_idle(struct srcu_struct *ssp)
> > spin_unlock_irqrestore_rcu_node(sdp, flags);
> >
> > /*
> > - * No local callbacks, so probabalistically probe global state.
> > + * No local callbacks, so probabilistically probe global state.
> > * Exact information would require acquiring locks, which would
> > - * kill scalability, hence the probabalistic nature of the probe.
> > + * kill scalability, hence the probabilistic nature of the probe.
> > */
> >
> > /* First, see if enough time has passed since the last GP. */
> > diff --git a/kernel/rcu/sync.c b/kernel/rcu/sync.c
> > index d4558ab7a07d..3eeb871cf0de 100644
> > --- a/kernel/rcu/sync.c
> > +++ b/kernel/rcu/sync.c
> > @@ -94,7 +94,7 @@ static void rcu_sync_func(struct rcu_head *rhp)
> > rcu_sync_call(rsp);
> > } else {
> > /*
> > - * We're at least a GP after the last rcu_sync_exit(); eveybody
> > + * We're at least a GP after the last rcu_sync_exit(); everybody
> > * will now have observed the write side critical section.
> > * Let 'em rip!.
> > */
> > diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
> > index af7c19439f4e..ac3c362e08a3 100644
> > --- a/kernel/rcu/tasks.h
> > +++ b/kernel/rcu/tasks.h
> > @@ -23,7 +23,7 @@ typedef void (*postgp_func_t)(struct rcu_tasks *rtp);
> > * Definition for a Tasks-RCU-like mechanism.
> > * @cbs_head: Head of callback list.
> > * @cbs_tail: Tail pointer for callback list.
> > - * @cbs_wq: Wait queue allowning new callback to get kthread's attention.
> > + * @cbs_wq: Wait queue allowing new callback to get kthread's attention.
> > * @cbs_lock: Lock protecting callback list.
> > * @kthread_ptr: This flavor's grace-period/callback-invocation kthread.
> > * @gp_func: This flavor's grace-period-wait function.
> > @@ -504,7 +504,7 @@ DEFINE_RCU_TASKS(rcu_tasks, rcu_tasks_wait_gp, call_rcu_tasks, "RCU Tasks");
> > * or transition to usermode execution. As such, there are no read-side
> > * primitives analogous to rcu_read_lock() and rcu_read_unlock() because
> > * this primitive is intended to determine that all tasks have passed
> > - * through a safe state, not so much for data-strcuture synchronization.
> > + * through a safe state, not so much for data-structure synchronization.
> > *
> > * See the description of call_rcu() for more detailed information on
> > * memory ordering guarantees.
> > @@ -637,7 +637,7 @@ DEFINE_RCU_TASKS(rcu_tasks_rude, rcu_tasks_rude_wait_gp, call_rcu_tasks_rude,
> > * there are no read-side primitives analogous to rcu_read_lock() and
> > * rcu_read_unlock() because this primitive is intended to determine
> > * that all tasks have passed through a safe state, not so much for
> > - * data-strcuture synchronization.
> > + * data-structure synchronization.
> > *
>
> The "hyphen" in the middle of the word "data structure" is required or keeping by
> convention or has some significance?

Yes, this is one of many peculiarities of English, and an optional one
at that. English is not a block-structured language, so grouping can
be ambiguous. Is is "(data structure) synchronization" or is it instead
"data (structure synchronization)"? The default is the latter, and
the hyphen indicates the former. In this case, the former is intended,
hence the hyphen.

> > * See the description of call_rcu() for more detailed information on
> > * memory ordering guarantees.
> > @@ -1127,7 +1127,7 @@ static void exit_tasks_rcu_finish_trace(struct task_struct *t)
> > * there are no read-side primitives analogous to rcu_read_lock() and
> > * rcu_read_unlock() because this primitive is intended to determine
> > * that all tasks have passed through a safe state, not so much for
> > - * data-strcuture synchronization.
> > + * data-structure synchronization.
> > *
> Same like above.

Ditto!

Thanx, Paul

> > * See the description of call_rcu() for more detailed information on
> > * memory ordering guarantees.
> > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
> > index da6f5213fb74..ab5bd5b391e6 100644
> > --- a/kernel/rcu/tree.c
> > +++ b/kernel/rcu/tree.c
> > @@ -2490,7 +2490,7 @@ int rcutree_dead_cpu(unsigned int cpu)
> >
> > /*
> > * Invoke any RCU callbacks that have made it to the end of their grace
> > - * period. Thottle as specified by rdp->blimit.
> > + * period. Throttle as specified by rdp->blimit.
> > */
> > static void rcu_do_batch(struct rcu_data *rdp)
> > {
> > @@ -4013,7 +4013,7 @@ EXPORT_SYMBOL_GPL(rcu_barrier);
> > /*
> > * Propagate ->qsinitmask bits up the rcu_node tree to account for the
> > * first CPU in a given leaf rcu_node structure coming online. The caller
> > - * must hold the corresponding leaf rcu_node ->lock with interrrupts
> > + * must hold the corresponding leaf rcu_node ->lock with interrupts
> > * disabled.
> > */
> > static void rcu_init_new_rnp(struct rcu_node *rnp_leaf)
> > diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
> > index 71821d59d95c..abff7abd59ee 100644
> > --- a/kernel/rcu/tree.h
> > +++ b/kernel/rcu/tree.h
> > @@ -153,7 +153,7 @@ struct rcu_data {
> > unsigned long gp_seq; /* Track rsp->gp_seq counter. */
> > unsigned long gp_seq_needed; /* Track furthest future GP request. */
> > union rcu_noqs cpu_no_qs; /* No QSes yet for this CPU. */
> > - bool core_needs_qs; /* Core waits for quiesc state. */
> > + bool core_needs_qs; /* Core waits for quiescent state. */
> > bool beenonline; /* CPU online at least once. */
> > bool gpwrap; /* Possible ->gp_seq wrap. */
> > bool exp_deferred_qs; /* This CPU awaiting a deferred QS? */
> > diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
> > index 2d603771c7dc..2a28f05cf467 100644
> > --- a/kernel/rcu/tree_plugin.h
> > +++ b/kernel/rcu/tree_plugin.h
> > @@ -2772,7 +2772,7 @@ static void show_rcu_nocb_state(struct rcu_data *rdp)
> > wastimer = timer_pending(&rdp->nocb_bypass_timer);
> > wassleep = swait_active(&rdp->nocb_gp_wq);
> > if (!rdp->nocb_gp_sleep && !waslocked && !wastimer && !wassleep)
> > - return; /* Nothing untowards. */
> > + return; /* Nothing untoward. */
> >
> > pr_info(" nocb GP activity on CB-only CPU!!! %c%c%c%c %c\n",
> > "lL"[waslocked],
> > diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/locks.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/locks.h
> > index cf6938d679d7..1e24827f96f1 100644
> > --- a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/locks.h
> > +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/locks.h
> > @@ -174,7 +174,7 @@ static inline bool spin_trylock(spinlock_t *lock)
> > }
> >
> > struct completion {
> > - /* Hopefuly this won't overflow. */
> > + /* Hopefully this won't overflow. */
> > unsigned int count;
> > };
> >