[PATCH][RFC] lockdep: improve comments in wait-type checks
From: Zhouyi Zhou
Date: Tue Aug 10 2021 - 17:03:53 EST
Hi Peter,
I think comments in wait-type checks may benifit from some comments
improvement.
I recklessly add Paul to signed-off-by, because I asked his opinion
about comment in rcu_read_lock_bh part.
Thanks a lot
Zhouyi
Signed-off-by: Zhouyi Zhou <zhouzhouyi@xxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
include/linux/lockdep_types.h | 2 +-
kernel/locking/lockdep.c | 2 +-
kernel/rcu/update.c | 4 ++--
3 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/include/linux/lockdep_types.h b/include/linux/lockdep_types.h
index 3e726ace5c62..d22430840b53 100644
--- a/include/linux/lockdep_types.h
+++ b/include/linux/lockdep_types.h
@@ -21,7 +21,7 @@ enum lockdep_wait_type {
LD_WAIT_SPIN, /* spin loops, raw_spinlock_t etc.. */
#ifdef CONFIG_PROVE_RAW_LOCK_NESTING
- LD_WAIT_CONFIG, /* CONFIG_PREEMPT_LOCK, spinlock_t etc.. */
+ LD_WAIT_CONFIG, /* preemptible in PREEMPT_RT, spinlock_t etc.. */
#else
LD_WAIT_CONFIG = LD_WAIT_SPIN,
#endif
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index bf1c00c881e4..952d0ccf8776 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -4671,7 +4671,7 @@ print_lock_invalid_wait_context(struct task_struct *curr,
/*
* Verify the wait_type context.
*
- * This check validates we takes locks in the right wait-type order; that is it
+ * This check validates we take locks in the right wait-type order; that is it
* ensures that we do not take mutexes inside spinlocks and do not attempt to
* acquire spinlocks inside raw_spinlocks and the sort.
*
diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index c21b38cc25e9..690b0cec7459 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -247,7 +247,7 @@ struct lockdep_map rcu_lock_map = {
.name = "rcu_read_lock",
.key = &rcu_lock_key,
.wait_type_outer = LD_WAIT_FREE,
- .wait_type_inner = LD_WAIT_CONFIG, /* XXX PREEMPT_RCU ? */
+ .wait_type_inner = LD_WAIT_CONFIG, /* PREEMPT_RT implies PREEMPT_RCU */
};
EXPORT_SYMBOL_GPL(rcu_lock_map);
@@ -256,7 +256,7 @@ struct lockdep_map rcu_bh_lock_map = {
.name = "rcu_read_lock_bh",
.key = &rcu_bh_lock_key,
.wait_type_outer = LD_WAIT_FREE,
- .wait_type_inner = LD_WAIT_CONFIG, /* PREEMPT_LOCK also makes BH preemptible */
+ .wait_type_inner = LD_WAIT_CONFIG, /* PREEMPT_RT makes BH preemptible. */
};
EXPORT_SYMBOL_GPL(rcu_bh_lock_map);
--
2.25.1