On Mon, May 6, 2019 at 5:31 AM David Sterba <dsterba@xxxxxxx> wrote: > for the reference https://bugzilla.kernel.org/show_bug.cgi?id=202803 > and https://github.com/systemd/systemd/issues/11939 I've read these, but can't tell if it's still necessary to manually use 'btrfs-map-physical' to find the correct offset, and use it on the kernel command line manually? It does sound like contiguous extents is not a requirement for hibernation to a swapfile on btrfs. Correct? The idea I'm evaluating is a way to dynamically enable a swapfile only at hibernation time. That way there's no swap thrashing during normal use, yet it's still possible to support hibernation. It'd be necessary to insert the swapon quickly after a request (or pre-trigger, maybe by upowerd) for hibernation, so that the various systemd tests already find a suitable swap device for the hibernation image. -- Chris Murphy
