2021-08-11 03:05:39

by Zhouyi Zhou

[permalink] [raw]
Subject: [PATCH V2][RFC] lockdep: improve comments in wait-type checks

comments in wait-type checks be improved by mentioning the
PREEPT_RT kernel configure option.

Many thanks
Zhouyi

Acked-by: Paul E. McKenney <[email protected]>
Signed-off-by: Zhouyi Zhou <[email protected]>
---
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


2021-08-24 13:54:03

by Peter Zijlstra

[permalink] [raw]
Subject: Re: [PATCH V2][RFC] lockdep: improve comments in wait-type checks

On Wed, Aug 11, 2021 at 10:59:20AM +0800, Zhouyi Zhou wrote:
> comments in wait-type checks be improved by mentioning the
> PREEPT_RT kernel configure option.
>
> Many thanks
> Zhouyi
>
> Acked-by: Paul E. McKenney <[email protected]>
> Signed-off-by: Zhouyi Zhou <[email protected]>

Acked goes after sobs, fixed that for you.

Thanks!

2021-08-24 14:46:31

by Zhouyi Zhou

[permalink] [raw]
Subject: Re: [PATCH V2][RFC] lockdep: improve comments in wait-type checks

On Tue, Aug 24, 2021 at 9:50 PM Peter Zijlstra <[email protected]> wrote:
>
> On Wed, Aug 11, 2021 at 10:59:20AM +0800, Zhouyi Zhou wrote:
> > comments in wait-type checks be improved by mentioning the
> > PREEPT_RT kernel configure option.
> >
> > Many thanks
> > Zhouyi
> >
> > Acked-by: Paul E. McKenney <[email protected]>
> > Signed-off-by: Zhouyi Zhou <[email protected]>
>
> Acked goes after sobs, fixed that for you.
>
> Thanks!
Sincere thanks for your help and guidance

Zhouyi ;-)

2021-09-17 21:08:50

by tip-bot2 for Jacob Pan

[permalink] [raw]
Subject: [tip: locking/core] lockdep: Improve comments in wait-type checks

The following commit has been merged into the locking/core branch of tip:

Commit-ID: a2e05ddda11b0bd529f443df9089ab498b2c2642
Gitweb: https://git.kernel.org/tip/a2e05ddda11b0bd529f443df9089ab498b2c2642
Author: Zhouyi Zhou <[email protected]>
AuthorDate: Wed, 11 Aug 2021 10:59:20 +08:00
Committer: Peter Zijlstra <[email protected]>
CommitterDate: Fri, 17 Sep 2021 15:08:45 +02:00

lockdep: Improve comments in wait-type checks

Comments in wait-type checks be improved by mentioning the
PREEPT_RT kernel configure option.

Signed-off-by: Zhouyi Zhou <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Acked-by: Paul E. McKenney <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
---
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 3e726ac..d224308 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 bfa0a34..4e63129 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 c21b38c..690b0ce 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);