Input: evdev - Add the events() callback
By sending a full frame of events at the same time, the irqsoff
latency at heavy load is brought down from 200 us to 100 us.
Cc: Daniel Kurtz <djkurtz@chromium.org>
Tested-by: Benjamin Tissoires <benjamin.tissoires@enac.fr>
Tested-by: Ping Cheng <pingc@wacom.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index a0692c5..118d030 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -54,16 +54,9 @@
static struct evdev *evdev_table[EVDEV_MINORS];
static DEFINE_MUTEX(evdev_table_mutex);
-static void evdev_pass_event(struct evdev_client *client,
- struct input_event *event,
- ktime_t mono, ktime_t real)
+static void __pass_event(struct evdev_client *client,
+ const struct input_event *event)
{
- event->time = ktime_to_timeval(client->clkid == CLOCK_MONOTONIC ?
- mono : real);
-
- /* Interrupts are disabled, just acquire the lock. */
- spin_lock(&client->buffer_lock);
-
client->buffer[client->head++] = *event;
client->head &= client->bufsize - 1;
@@ -86,8 +79,63 @@
client->packet_head = client->head;
kill_fasync(&client->fasync, SIGIO, POLL_IN);
}
+}
+
+static void evdev_pass_values(struct evdev_client *client,
+ const struct input_value *vals, unsigned int count,
+ ktime_t mono, ktime_t real)
+{
+ struct evdev *evdev = client->evdev;
+ const struct input_value *v;
+ struct input_event event;
+ bool wakeup = false;
+
+ event.time = ktime_to_timeval(client->clkid == CLOCK_MONOTONIC ?
+ mono : real);
+
+ /* Interrupts are disabled, just acquire the lock. */
+ spin_lock(&client->buffer_lock);
+
+ for (v = vals; v != vals + count; v++) {
+ event.type = v->type;
+ event.code = v->code;
+ event.value = v->value;
+ __pass_event(client, &event);
+ if (v->type == EV_SYN && v->code == SYN_REPORT)
+ wakeup = true;
+ }
spin_unlock(&client->buffer_lock);
+
+ if (wakeup)
+ wake_up_interruptible(&evdev->wait);
+}
+
+/*
+ * Pass incoming events to all connected clients.
+ */
+static void evdev_events(struct input_handle *handle,
+ const struct input_value *vals, unsigned int count)
+{
+ struct evdev *evdev = handle->private;
+ struct evdev_client *client;
+ ktime_t time_mono, time_real;
+
+ time_mono = ktime_get();
+ time_real = ktime_sub(time_mono, ktime_get_monotonic_offset());
+
+ rcu_read_lock();
+
+ client = rcu_dereference(evdev->grab);
+
+ if (client)
+ evdev_pass_values(client, vals, count, time_mono, time_real);
+ else
+ list_for_each_entry_rcu(client, &evdev->client_list, node)
+ evdev_pass_values(client, vals, count,
+ time_mono, time_real);
+
+ rcu_read_unlock();
}
/*
@@ -96,32 +144,9 @@
static void evdev_event(struct input_handle *handle,
unsigned int type, unsigned int code, int value)
{
- struct evdev *evdev = handle->private;
- struct evdev_client *client;
- struct input_event event;
- ktime_t time_mono, time_real;
+ struct input_value vals[] = { { type, code, value } };
- time_mono = ktime_get();
- time_real = ktime_sub(time_mono, ktime_get_monotonic_offset());
-
- event.type = type;
- event.code = code;
- event.value = value;
-
- rcu_read_lock();
-
- client = rcu_dereference(evdev->grab);
-
- if (client)
- evdev_pass_event(client, &event, time_mono, time_real);
- else
- list_for_each_entry_rcu(client, &evdev->client_list, node)
- evdev_pass_event(client, &event, time_mono, time_real);
-
- rcu_read_unlock();
-
- if (type == EV_SYN && code == SYN_REPORT)
- wake_up_interruptible(&evdev->wait);
+ evdev_events(handle, vals, 1);
}
static int evdev_fasync(int fd, struct file *file, int on)
@@ -1050,6 +1075,7 @@
static struct input_handler evdev_handler = {
.event = evdev_event,
+ .events = evdev_events,
.connect = evdev_connect,
.disconnect = evdev_disconnect,
.fops = &evdev_fops,