On 07/26/2012 11:26 AM, Rich Freeman wrote: > Implementing it wouldn't necessarily be hard - just create a tmpfs > under /var/tmp/portage, unshare off a new mount namespace, and > read-only bind-mount everything needed from the root filesystem > (including /var/tmp/portage/...), and chroot into it. When the build > is done the process governing it terminates and the kernel wipes out > all the mounts and then portage unmounts the tmpfs. You wouldn't need > to use a tmpfs for the build - it would actually be zero-size as > reported by df since it just contains a bazillion bind mounts, though > all those mounts would consume slab memory.
It seems like you might need some kind of copy-on-write support, at least to run pkg_setup. Apparently cowbuilder uses cow hardlinks for that. Another way would be to use fiemap (cp --reflink). -- Thanks, Zac
