Reclaim space from unused ramdisk?

I wonder if it would be possible to somehow reclaim space that has been previously reserved for a ramdisk without rebooting. I read the ramdisk docs in the latest kernel source and it seems that it is not currently possible. However, the kernel keeps track of the memory allocated for said ramdisk

tun device supplementary group ownership

Hi, It seems to me that supplementary groups should be taken into account when checking for permissions on a tun device. Can someone comment on my patch below; is it a reasonable approach? If so, I'd like to submit it for inclusion in the kernel under the GPL. Please forward any responses to me

group ownership of tun devices -- nonfunctional?

Per the post here: http://lkml.org/lkml/2007/6/18/228 it appears that the group ownership patch has made it into .23. I am using these patches, amongst which the kernel component appears to be identical: http://sigxcpu.org/unsorted-patches/0001-allow-tun-ownership-by-group.patch http://sigxcpu.