- Test --numa_node 0 case
- Support profiling
  - Support rss recording and reporting wss/rss
  - Support flamegraph-wss-heatmap visualization
- Support 'cleanup': echo 0 > nr_kdamonds
- Implement histogram stat regions output
- Deprecate old features
  - Deprecate translate_damos (done.)
  - Deprecate single line per-scheme (done.  code moved to _damon_deprecated)
  - Deprecate v1-v3 schemes (done.  necessary code moved to _damon_deprecated)
  - Deprecate python2 support (done.  code moved to _damon_deprecated)
  - Deprecate scheme subcommand
    - Can be replaced by start or tune
  - Deprecate old scheme usages in tests
  - Deprecate DAMON results record binary format (done.  code moved to
    _damon_deprecated)
- damo show features implementation
  - support target damos filter
  - time based filtering
  - collapse by time
  - collapse by priority value (more histogram control)
  - Implement min/max snapshot format keyword
- Test DAMOS interval
- Test quota goals
- Handle quota goals tuning error / invalid inputs better
- Get sysfs/debugfs mount point from /proc/mounts file
- damo show: use pager if the output is too long
- Re-write sysfs/debugfs without features detection

Current sysfs/debugfs constructs every file i/o at once and submit it to
_damo_fs.  Since the whole set of i/o operations should success, those require
features detection, which makes damo stateful.  Rewrite it to do i/o one by one
and handle unsupported features on the fly.
