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| author | Hans Verkuil <hverkuil@xs4all.nl> | 2010-11-26 06:47:28 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2010-12-01 20:10:19 -0200 |
| commit | 879aa24d6394aa04b690a600a41ff500441ad384 (patch) | |
| tree | 024886e8a84ab3f7e88c1e2c5aeceae28cc344bb /drivers/media/video/v4l2-device.c | |
| parent | 2877842de8cbf6272b0a851cb12587b7dd8c2afb (diff) | |
| download | op-kernel-dev-879aa24d6394aa04b690a600a41ff500441ad384.zip op-kernel-dev-879aa24d6394aa04b690a600a41ff500441ad384.tar.gz | |
[media] V4L: improve the BKL replacement heuristic
The BKL replacement mutex had some serious performance side-effects on
V4L drivers. It is replaced by a better heuristic that works around the
worst of the side-effects.
Read the v4l2-dev.c comments for the whole sorry story. This is a
temporary measure only until we can convert all v4l drivers to use
unlocked_ioctl.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media/video/v4l2-device.c')
| -rw-r--r-- | drivers/media/video/v4l2-device.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/media/video/v4l2-device.c b/drivers/media/video/v4l2-device.c index 0b08f96..7fe6f92 100644 --- a/drivers/media/video/v4l2-device.c +++ b/drivers/media/video/v4l2-device.c @@ -35,6 +35,7 @@ int v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev) INIT_LIST_HEAD(&v4l2_dev->subdevs); spin_lock_init(&v4l2_dev->lock); + mutex_init(&v4l2_dev->ioctl_lock); v4l2_dev->dev = dev; if (dev == NULL) { /* If dev == NULL, then name must be filled in by the caller */ |
