Here is what I got so far on perfmon for 2.5.31. It includes:

- your randomization patch with some rework to make it visible to user.
  (your existing program does not need to change or recompilation).

- 3 error conditions cleanups, a missing unlock fix

- copy_*user() replaced with __copy_*_user() or get/put user when appropriate.
  (This gives us a 15% speed improvement on PFM_READ_PMDS).

- sys_perfmonctl(), only check for read-only OR read-write arguments
  (read and write are not separated anymore)

- Non 64-bit overflow do not reset hardware pmd to zero anymore: not needed

- incorporated changes from 2.4.18/9: debug registers when used are
  all restored on ctxsw in.

- added automatic reset on inheritance, no more PMU specific knowledge.