swap on eMMC and other flash

[Hugh Dickins]

On Mon, 2 Apr 2012, Arnd Bergmann wrote:
> 
> Another option would be batched discard as we do it for file systems:
> occasionally stop writing to swap space and scanning for areas that
> have become available since the last discard, then send discard
> commands for those.

I'm not sure whether you've missed "swapon --discard", which switches
on discard_swap_cluster() just before we allocate from a new cluster;
or whether you're musing that it's no use to you because you want to
repurpose the swap cluster to match erase block: I'm mentioning it in
case you missed that it's already there (but few use it, since even
done at that scale it's often more trouble than it's worth).

Hugh