[PATCH 0/7] shrinker debugging improvements

[Kent Overstreet <kent.overstreet@linux.dev>]

This patchset does a few things to aid in OOM debugging, in particular
when shrinkers are involved:

 - improves the show_mem OOM report: it now reports on shrinkers, and
   for both shrinkers and slab we only report the top 10 entries,
   sorted, not the full list

 - add shrinker_to_text(), for the show_mem report and debugfs, and a
   an optional shrinker.to_text() callback to report extra
   driver-specific information

 - add extra counters for the shrinker_to_text() report

 - implement shrinker.to_text() for bcachefs, giving an example of how
   to use the callbacks

Daniel Hill (1):
  bcachefs: add counters for failed shrinker reclaim

Kent Overstreet (6):
  seq_buf: seq_buf_human_readable_u64()
  mm: shrinker: Add a .to_text() method for shrinkers
  mm: shrinker: Add new stats for .to_text()
  mm: Centralize & improve oom reporting in show_mem.c
  mm: shrinker: Add shrinker_to_text() to debugfs interface
  bcachefs: shrinker.to_text() methods

 fs/bcachefs/btree_cache.c     | 102 +++++++++++++++++++++++++++-------
 fs/bcachefs/btree_cache.h     |   2 +-
 fs/bcachefs/btree_key_cache.c |  14 +++++
 fs/bcachefs/btree_types.h     |  10 ++++
 fs/bcachefs/sysfs.c           |   2 +-
 include/linux/seq_buf.h       |   4 ++
 include/linux/shrinker.h      |  12 +++-
 lib/seq_buf.c                 |  10 ++++
 mm/oom_kill.c                 |  23 --------
 mm/show_mem.c                 |  20 +++++++
 mm/shrinker.c                 |  89 ++++++++++++++++++++++++++++-
 mm/shrinker_debug.c           |  18 ++++++
 mm/slab.h                     |   6 +-
 mm/slab_common.c              |  52 ++++++++++++++---
 14 files changed, 305 insertions(+), 59 deletions(-)

-- 
2.42.0