Messages in this thread | | | Date | Mon, 26 May 2008 13:59:51 -0300 | From | Mauro Carvalho Chehab <> | Subject | Re: [PATCH] video4linux: Push down the BKL |
| |
On Thu, 22 May 2008 22:37:00 +0100 Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:
> For most drivers the generic ioctl handler does the work and we update it > and it becomes the unlocked_ioctl method. Older drivers use the usercopy > method so we make it do the work. Finally there are a few special cases.
I liked the patch also.
Still, it didn't apply cleanly on my -git tree, probably due to some fixes at cx18 and ivtv (see the attached log). Also, IMO, it would be better if you split drivers/net/tun.c into a different changeset.
I think you should add a video_ioctl2_unlocked() function, without BKL (and keeping BKL explicit locks at video_ioctl2). This would help on migrating the drivers to the unlocked version, since I suspect that most drivers already have enough locks for the removal of BKL.
I would just implement video_ioctl2 as:
video_ioctl2_locked (...) { lock_kernel(); video_ioctl2_unlocked(); unlock_kernel(); }
The next step can be to add the obvious locks inside video_ioctl2_unlocked(). Like, for example, locking the VIDIOC_S calls, if someone is calling the corresponding VIDIOC_G or VIDIOC_TRY ones.
Cheers, Mauro.
---
patching file drivers/media/video/bt8xx/bttv-driver.c patching file drivers/media/video/bw-qcam.c patching file drivers/media/video/c-qcam.c patching file drivers/media/video/cafe_ccic.c patching file drivers/media/video/cpia.c patching file drivers/media/video/cpia2/cpia2_v4l.c patching file drivers/media/video/cx18/cx18-ioctl.c patching file drivers/media/video/cx18/cx18-ioctl.h patching file drivers/media/video/cx18/cx18-streams.c Hunk #1 FAILED at 39. 1 out of 1 hunk FAILED -- saving rejects to file drivers/media/video/cx18/cx18-streams.c.rej patching file drivers/media/video/cx23885/cx23885-417.c patching file drivers/media/video/cx23885/cx23885-video.c patching file drivers/media/video/cx88/cx88-blackbird.c patching file drivers/media/video/cx88/cx88-video.c patching file drivers/media/video/dabusb.c patching file drivers/media/video/em28xx/em28xx-video.c patching file drivers/media/video/et61x251/et61x251_core.c patching file drivers/media/video/ivtv/ivtv-ioctl.c patching file drivers/media/video/ivtv/ivtv-ioctl.h Hunk #1 FAILED at 24. 1 out of 1 hunk FAILED -- saving rejects to file drivers/media/video/ivtv/ivtv-ioctl.h.rej patching file drivers/media/video/ivtv/ivtv-streams.c Hunk #1 FAILED at 48. Hunk #2 FAILED at 58. 2 out of 2 hunks FAILED -- saving rejects to file drivers/media/video/ivtv/ivtv-streams.c.rej patching file drivers/media/video/meye.c patching file drivers/media/video/ov511.c patching file drivers/media/video/pms.c patching file drivers/media/video/pvrusb2/pvrusb2-v4l2.c Hunk #1 succeeded at 861 (offset -1 lines). Hunk #2 succeeded at 869 (offset -1 lines). Hunk #3 succeeded at 1153 (offset -1 lines). patching file drivers/media/video/pwc/pwc-if.c patching file drivers/media/video/saa5246a.c patching file drivers/media/video/saa5249.c patching file drivers/media/video/saa7134/saa7134-empress.c patching file drivers/media/video/saa7134/saa7134-video.c patching file drivers/media/video/se401.c patching file drivers/media/video/sn9c102/sn9c102_core.c patching file drivers/media/video/soc_camera.c patching file drivers/media/video/stk-webcam.c Hunk #1 succeeded at 1320 (offset 7 lines). patching file drivers/media/video/stradis.c patching file drivers/media/video/stv680.c patching file drivers/media/video/usbvideo/usbvideo.c patching file drivers/media/video/usbvideo/vicam.c patching file drivers/media/video/usbvision/usbvision-video.c patching file drivers/media/video/videodev.c patching file drivers/media/video/vivi.c patching file drivers/media/video/w9966.c patching file drivers/media/video/w9968cf.c patching file drivers/media/video/zc0301/zc0301_core.c patching file drivers/media/video/zoran_driver.c patching file drivers/media/video/zr364xx.c patching file drivers/net/tun.c patching file include/media/v4l2-dev.h Hunk #1 succeeded at 343 (offset -1 lines). Hunk #2 succeeded at 352 (offset -1 lines).
| |