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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 /include/media | |
| parent | 2877842de8cbf6272b0a851cb12587b7dd8c2afb (diff) | |
| download | blackbird-op-linux-879aa24d6394aa04b690a600a41ff500441ad384.tar.gz blackbird-op-linux-879aa24d6394aa04b690a600a41ff500441ad384.zip | |
[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 'include/media')
| -rw-r--r-- | include/media/v4l2-device.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/media/v4l2-device.h b/include/media/v4l2-device.h index 6648036b728d..b16f307d471a 100644 --- a/include/media/v4l2-device.h +++ b/include/media/v4l2-device.h @@ -51,6 +51,8 @@ struct v4l2_device { unsigned int notification, void *arg); /* The control handler. May be NULL. */ struct v4l2_ctrl_handler *ctrl_handler; + /* BKL replacement mutex. Temporary solution only. */ + struct mutex ioctl_lock; }; /* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev. |
