tools/mm: add page_owner_filter userspace tool

Add a userspace filtering tool for page_owner that supports per-fd
filtering with print_mode and NUMA node filters.

Features:
- Three print modes: stack (default), handle, stack_handle
- NUMA node filtering with flexible formats (single: 0, multiple: 0,1,2,
  range: 0-3, mixed: 0,2-3)
- Per-file-descriptor filter state for independent filtering

Usage examples:
  # Filter by print mode
  ./page_owner_filter -m handle
  ./page_owner_filter -m stack_handle

  # Filter by NUMA node
  ./page_owner_filter -n 0
  ./page_owner_filter -n 0-3

  # Combined filters
  ./page_owner_filter -m stack -n 0,1,2
  ./page_owner_filter -m handle -n 0,2-3

The tool validates inputs before sending commands to the kernel and
provides clear error messages when the kernel does not support
per-fd filtering.

Link: https://lore.kernel.org/20260707115411.1714314-4-zhen.ni@easystack.cn
Signed-off-by: Zhen Ni <zhen.ni@easystack.cn>
Tested-by: Zi Yan <ziy@nvidia.com>
Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Acked-by: Zi Yan <ziy@nvidia.com>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

0 files changed, 0 insertions, 0 deletions