Messages in this thread | | | Date | Fri, 23 May 2008 16:39:56 +0100 | From | Alan Cox <> | Subject | Re: [PATCH] video4linux: Push down the BKL |
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> On the other hand, the next level of BKL pushdown would be painful as > all hell, given the massive number of callbacks in the V4L2 API. So I'm > thinking it might be justified to create a video_ioctl2_locked() for > V4L2 drivers which are not yet known to be safe in the absence of the > BKL. The amount of extra code would be quite small, and it would let > safe drivers operate BKL-free.
The problem is that currently they are almost all unsafe - I did a quick survey as part of the changes. Pushing it down to the video2_ioctl is a starting point, but the v4l layer is going to need a lot of love and its own gradual migration.
Right now we've gone from BKL buried in fs to BKL at top of v4l layer which is indeed only a starting point. I'd assumed the same as you are think a new video_ioctl2 and switching drivers one by one (I was assuming adding video2_ioctl_unlocked())
Alan
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