[PATCH 0/3] mm,TPP: Enable promotion of unmapped pagecache

[Gregory Price]

Unmapped pagecache pages can be demoted to low-tier memory, but 
they can only be promoted if a process maps the pages into the
memory space (so that NUMA hint faults can be caught).  This can
cause significant performance degradation as the pagecache ages
and unmapped, cached files are accessed.

This patch series enables the pagecache to request a promotion of
a folio when it is accessed via the pagecache.

We add a new `numa_hint_page_cache` counter in vmstat to capture
information on when these migrations occur.

Gregory Price (3):
  migrate: Allow migrate_misplaced_folio APIs without a VMA
  memory: allow non-fault migration in numa_migrate_prep path
  swap: enable promotion for unmapped pagecache on access

 include/linux/migrate.h       |  6 ++----
 include/linux/vm_event_item.h |  1 +
 mm/huge_memory.c              |  2 +-
 mm/memory.c                   | 21 +++++++++++----------
 mm/mempolicy.c                | 25 +++++++++++++++++--------
 mm/migrate.c                  |  7 +++----
 mm/swap.c                     | 20 ++++++++++++++++++++
 mm/vmstat.c                   |  1 +
 8 files changed, 56 insertions(+), 27 deletions(-)

-- 
2.43.0