* [PATCH] driver core: bus: move lock_class_key into dynamic structure
@ 2023-02-01 8:33 Greg Kroah-Hartman
2023-02-01 18:59 ` Rafael J. Wysocki
0 siblings, 1 reply; 3+ messages in thread
From: Greg Kroah-Hartman @ 2023-02-01 8:33 UTC (permalink / raw)
To: linux-kernel; +Cc: Greg Kroah-Hartman, Rafael J. Wysocki
Move the lock_class_key structure out of struct bus_type and into the
dynamic structure we create already for all bus_types registered with
the kernel. This saves on static space and removes one more writable
field in struct bus_type.
In the future, the same field can be moved out of the struct class logic
because it shares this same private structure.
Most everyone will never notice this change, as lockdep is not enabled
in real systems so no memory or logic changes are happening for them.
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/base/base.h | 2 ++
drivers/base/bus.c | 5 ++++-
include/linux/device/bus.h | 1 -
3 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/base/base.h b/drivers/base/base.h
index 2208af509ce8..0e806f641079 100644
--- a/drivers/base/base.h
+++ b/drivers/base/base.h
@@ -52,6 +52,8 @@ struct subsys_private {
struct kset glue_dirs;
struct class *class;
+
+ struct lock_class_key lock_key;
};
#define to_subsys_private(obj) container_of_const(obj, struct subsys_private, subsys.kobj)
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index cf1b8f00b4c0..aa70b3a7d778 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -154,6 +154,7 @@ static void bus_release(struct kobject *kobj)
struct subsys_private *priv = to_subsys_private(kobj);
struct bus_type *bus = priv->bus;
+ lockdep_unregister_key(&priv->lock_key);
kfree(priv);
bus->p = NULL;
}
@@ -743,7 +744,7 @@ int bus_register(struct bus_type *bus)
{
int retval;
struct subsys_private *priv;
- struct lock_class_key *key = &bus->lock_key;
+ struct lock_class_key *key;
priv = kzalloc(sizeof(struct subsys_private), GFP_KERNEL);
if (!priv)
@@ -785,6 +786,8 @@ int bus_register(struct bus_type *bus)
}
INIT_LIST_HEAD(&priv->interfaces);
+ key = &priv->lock_key;
+ lockdep_register_key(key);
__mutex_init(&priv->mutex, "subsys mutex", key);
klist_init(&priv->klist_devices, klist_devices_get, klist_devices_put);
klist_init(&priv->klist_drivers, NULL, NULL);
diff --git a/include/linux/device/bus.h b/include/linux/device/bus.h
index 87e4d029c915..e3094db1e9fa 100644
--- a/include/linux/device/bus.h
+++ b/include/linux/device/bus.h
@@ -112,7 +112,6 @@ struct bus_type {
const struct iommu_ops *iommu_ops;
struct subsys_private *p;
- struct lock_class_key lock_key;
bool need_parent_lock;
};
--
2.39.1
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] driver core: bus: move lock_class_key into dynamic structure
2023-02-01 8:33 [PATCH] driver core: bus: move lock_class_key into dynamic structure Greg Kroah-Hartman
@ 2023-02-01 18:59 ` Rafael J. Wysocki
2023-02-01 19:03 ` Greg Kroah-Hartman
0 siblings, 1 reply; 3+ messages in thread
From: Rafael J. Wysocki @ 2023-02-01 18:59 UTC (permalink / raw)
To: Greg Kroah-Hartman; +Cc: linux-kernel, Rafael J. Wysocki
On Wed, Feb 1, 2023 at 9:33 AM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> Move the lock_class_key structure out of struct bus_type and into the
> dynamic structure we create already for all bus_types registered with
> the kernel. This saves on static space and removes one more writable
> field in struct bus_type.
>
> In the future, the same field can be moved out of the struct class logic
> because it shares this same private structure.
>
> Most everyone will never notice this change, as lockdep is not enabled
> in real systems so no memory or logic changes are happening for them.
>
> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This looks reasonable to me, so
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
> ---
> drivers/base/base.h | 2 ++
> drivers/base/bus.c | 5 ++++-
> include/linux/device/bus.h | 1 -
> 3 files changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/base/base.h b/drivers/base/base.h
> index 2208af509ce8..0e806f641079 100644
> --- a/drivers/base/base.h
> +++ b/drivers/base/base.h
> @@ -52,6 +52,8 @@ struct subsys_private {
>
> struct kset glue_dirs;
> struct class *class;
> +
> + struct lock_class_key lock_key;
> };
> #define to_subsys_private(obj) container_of_const(obj, struct subsys_private, subsys.kobj)
>
> diff --git a/drivers/base/bus.c b/drivers/base/bus.c
> index cf1b8f00b4c0..aa70b3a7d778 100644
> --- a/drivers/base/bus.c
> +++ b/drivers/base/bus.c
> @@ -154,6 +154,7 @@ static void bus_release(struct kobject *kobj)
> struct subsys_private *priv = to_subsys_private(kobj);
> struct bus_type *bus = priv->bus;
>
> + lockdep_unregister_key(&priv->lock_key);
> kfree(priv);
> bus->p = NULL;
> }
> @@ -743,7 +744,7 @@ int bus_register(struct bus_type *bus)
> {
> int retval;
> struct subsys_private *priv;
> - struct lock_class_key *key = &bus->lock_key;
> + struct lock_class_key *key;
>
> priv = kzalloc(sizeof(struct subsys_private), GFP_KERNEL);
> if (!priv)
> @@ -785,6 +786,8 @@ int bus_register(struct bus_type *bus)
> }
>
> INIT_LIST_HEAD(&priv->interfaces);
> + key = &priv->lock_key;
> + lockdep_register_key(key);
> __mutex_init(&priv->mutex, "subsys mutex", key);
> klist_init(&priv->klist_devices, klist_devices_get, klist_devices_put);
> klist_init(&priv->klist_drivers, NULL, NULL);
> diff --git a/include/linux/device/bus.h b/include/linux/device/bus.h
> index 87e4d029c915..e3094db1e9fa 100644
> --- a/include/linux/device/bus.h
> +++ b/include/linux/device/bus.h
> @@ -112,7 +112,6 @@ struct bus_type {
> const struct iommu_ops *iommu_ops;
>
> struct subsys_private *p;
> - struct lock_class_key lock_key;
>
> bool need_parent_lock;
> };
> --
> 2.39.1
>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] driver core: bus: move lock_class_key into dynamic structure
2023-02-01 18:59 ` Rafael J. Wysocki
@ 2023-02-01 19:03 ` Greg Kroah-Hartman
0 siblings, 0 replies; 3+ messages in thread
From: Greg Kroah-Hartman @ 2023-02-01 19:03 UTC (permalink / raw)
To: Rafael J. Wysocki; +Cc: linux-kernel
On Wed, Feb 01, 2023 at 07:59:42PM +0100, Rafael J. Wysocki wrote:
> On Wed, Feb 1, 2023 at 9:33 AM Greg Kroah-Hartman
> <gregkh@linuxfoundation.org> wrote:
> >
> > Move the lock_class_key structure out of struct bus_type and into the
> > dynamic structure we create already for all bus_types registered with
> > the kernel. This saves on static space and removes one more writable
> > field in struct bus_type.
> >
> > In the future, the same field can be moved out of the struct class logic
> > because it shares this same private structure.
> >
> > Most everyone will never notice this change, as lockdep is not enabled
> > in real systems so no memory or logic changes are happening for them.
> >
> > Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>
> This looks reasonable to me, so
>
> Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Thanks for the review.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2023-02-01 8:33 [PATCH] driver core: bus: move lock_class_key into dynamic structure Greg Kroah-Hartman
2023-02-01 18:59 ` Rafael J. Wysocki
2023-02-01 19:03 ` Greg Kroah-Hartman
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