Messages in this thread | | | From | "Rafael J. Wysocki" <> | Date | Wed, 1 Feb 2023 19:59:42 +0100 | Subject | Re: [PATCH] driver core: bus: move lock_class_key into dynamic structure |
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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 >
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