swapoff appears to be broken on 2.4.3-12. Running swapoff -a on 2.2 used
to take about as long as it would to read the data back into memory, but in
recent 2.4 it seems to lock up the system with no LED activity for a good
while. It eventually comes back after several minutes, but this isn't
IIRC there was a thread about this on lkml some time ago.
There was. And it appears the very brand spanking new kernels (2.4.6pre5)
have _some_ improvements in this area, although it's far from perfect.