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Input: use full RCU API

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RT guys alerted me to the fact that in their tree spinlocks
are preemptible and it is better to use full RCU API
(rcu_read_lock()/rcu_read_unlock()) to be safe.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This commit is contained in:
Dmitry Torokhov
2007-10-13 15:46:55 -04:00
parent 70093178b6
commit 82ba56c273
4 changed files with 32 additions and 48 deletions
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22
drivers/input/evdev.c
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@@ -63,10 +63,7 @@ static void evdev_pass_event(struct evdev_client *client,
}
/*
* Pass incoming event to all connected clients. Note that we are
* caleld under a spinlock with interrupts off so we don't need
* to use rcu_read_lock() here. Writers will be using syncronize_sched()
* instead of synchrnoize_rcu().
* Pass incoming event to all connected clients.
*/
static void evdev_event(struct input_handle *handle,
unsigned int type, unsigned int code, int value)
@@ -80,6 +77,8 @@ static void evdev_event(struct input_handle *handle,
event.code = code;
event.value = value;
rcu_read_lock();
client = rcu_dereference(evdev->grab);
if (client)
evdev_pass_event(client, &event);
@@ -87,6 +86,8 @@ static void evdev_event(struct input_handle *handle,
list_for_each_entry_rcu(client, &evdev->client_list, node)
evdev_pass_event(client, &event);
rcu_read_unlock();
wake_up_interruptible(&evdev->wait);
}
@@ -142,12 +143,7 @@ static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
return error;
rcu_assign_pointer(evdev->grab, client);
/*
* We don't use synchronize_rcu() here because read-side
* critical section is protected by a spinlock instead
* of rcu_read_lock().
*/
synchronize_sched();
synchronize_rcu();
return 0;
}
@@ -158,7 +154,7 @@ static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
return -EINVAL;
rcu_assign_pointer(evdev->grab, NULL);
synchronize_sched();
synchronize_rcu();
input_release_device(&evdev->handle);
return 0;
@@ -170,7 +166,7 @@ static void evdev_attach_client(struct evdev *evdev,
spin_lock(&evdev->client_lock);
list_add_tail_rcu(&client->node, &evdev->client_list);
spin_unlock(&evdev->client_lock);
synchronize_sched();
synchronize_rcu();
}
static void evdev_detach_client(struct evdev *evdev,
@@ -179,7 +175,7 @@ static void evdev_detach_client(struct evdev *evdev,
spin_lock(&evdev->client_lock);
list_del_rcu(&client->node);
spin_unlock(&evdev->client_lock);
synchronize_sched();
synchronize_rcu();
}
static int evdev_open_device(struct evdev *evdev)