On Friday, December 24, 2010 22:29:37 Rob Clark wrote: > Hi all, > > The request has come up on OMAP4 to support non-page-aligned v4l2 > buffers. (This is in context of v4l2 display, but the same reasons > would apply for a camera.) For most common resolutions, this would > help us get much better memory utilization for a range of memory (or > rather address space) used for YUV buffers. Can you explain this in more detail? I don't really see how non-page aligned buffers would lead to 'much better' memory usage. I would expect that the best savings you could achieve would be PAGE_SIZE-1 per buffer. Regards, Hans > However it would require > a small change in the client application, since most (all) v4l2 apps > that I have seen are assuming the offsets they are given to mmap are > page aligned. > > I am curious if anyone has any suggestions about how to enable this. > Ideally it would be some sort of opt-in feature to avoid breaking apps > that are not aware the the offsets to mmap may not be page aligned. > > BR, > -R > -- > To unsubscribe from this list: send the line "unsubscribe linux-media" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- Hans Verkuil - video4linux developer - sponsored by Cisco -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
