mm: shrinkers: add scan interface for shrinker debugfs

Add a scan interface which allows to trigger scanning of a particular
shrinker and specify memcg and numa node.  It's useful for testing,
debugging and profiling of a specific scan_objects() callback.  Unlike
alternatives (creating a real memory pressure and dropping caches via
/proc/sys/vm/drop_caches) this interface allows to interact with only one
shrinker at once.  Also, if a shrinker is misreporting the number of
objects (as some do), it doesn't affect scanning.

[[email protected]: improve typing, fix arg count checking]
  Link: https://lkml.kernel.org/r/YpgKttTowT22mKPQ@carbon
[[email protected]: fix arg count checking]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Roman Gushchin <[email protected]>
Acked-by: Muchun Song <[email protected]>
Cc: Christophe JAILLET <[email protected]>
Cc: Dave Chinner <[email protected]>
Cc: Hillf Danton <[email protected]>
Cc: Kent Overstreet <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions