[PATCH 0/3] tools/mm/page_owner_sort: fix --sort, add module filter, improve usage

[Ye Liu <ye.liu@linux.dev>]

From: Ye Liu <liuye@kylinos.cn>

This series improves the page_owner_sort tool with a bug fix, a new
module-name feature, and better usage text.

Patch 1 fixes a long-standing bug where --sort was silently ignored
when used without a short option (-a, -m, -p, etc.).  The COMP_NO_FLAG
case fell through to COMP_NUM and overwrote the sort conditions
configured by parse_sort_args().

Patch 2 adds kernel module name support for sort, cull, and filter
operations.  Page owner stack traces already contain module names in
the [module] format produced by %pS, but page_owner_sort had no way
to use them.  Records without module frames are assigned "vmlinux".

  # Aggregate page usage per module
  ./page_owner_sort input.txt output.txt --cull=mod

  # Filter to records from xfs module only
  ./page_owner_sort input.txt output.txt --module xfs

  # Sort by module name, then by pid descending
  ./page_owner_sort input.txt output.txt --sort=mod,-pid

Patch 3 lists all available sort keys with abbreviations and examples
directly in the --sort help section so users no longer need to read
the source to discover valid keys.

Ye Liu (3):
  tools/mm/page_owner_sort: fix --sort option being silently ignored
  tools/mm/page_owner_sort: add module name sort/cull/filter support
  tools/mm/page_owner_sort: show available sort keys in usage text

 Documentation/mm/page_owner.rst |   8 +-
 tools/mm/page_owner_sort.c      | 125 +++++++++++++++++++++++++++-----
 2 files changed, 113 insertions(+), 20 deletions(-)

-- 
2.25.1