[RFC PATCH 0/2] Fix gup_test long-term pin ownership

[Richard Cheng <icheng@nvidia.com>]

gup_test currently stores long-term pin state globally, allowing one
open file descriptor to block or release pins owned by another client.
Move this state to each open file description so independent clients
have isolated pin lifecycles.

Patch 1 moves long-term pin state from global variables to per-open
file state, preventing independent clients from affecting each other.

Patch 2 adds selftest coverage for concurrent pins and verifies that
stopping or closing one descriptor does not release another
descriptor's pin.


Richard Cheng (2):
  mm/gup_test: Track long-term pins per open file
  selftests/mm: Test per-open gup_test pin ownership

 mm/gup_test.c                             |  88 +++++---
 tools/testing/selftests/mm/gup_longterm.c | 258 +++++++++++++++++++++-
 2 files changed, 313 insertions(+), 33 deletions(-)


base-commit: 66498c75b4f8017f62d720d9b59675bdf3abce91
-- 
2.43.0