This patch series adds a memory.reclaim proactive reclaim interface. The rationale behind the interface and how it works are in the first patch. --- Changes in V5: - Fixed comment formating and added Co-developed-by in patch 1. - Modified selftest to work if swap is enabled or not, and retry multiple times to wait for background allocation before failing with a clear message. Changes in V4: mm/memcontrol.c: - Return -EINTR on signal_pending(). - On the final retry, drain percpu lru caches hoping that it might introduce some evictable pages for reclaim. - Simplified the retry loop as suggested by Dan Schatzberg. selftests: - Always return -errno on failure from cg_write() (whether open() or write() fail), also update cg_read() and read_text() to return -errno as well for consistency. Also make sure to correctly check that the whole buffer was written in cg_write(). - Added a maximum number of retries for the reclaim selftest. Changes in V3: - Fix cg_write() (in patch 2) to properly return -1 if open() fails and not fail if len == errno. - Remove debug printf() in patch 3. Changes in V2: - Add the interface to root as well. - Added a selftest. - Documented the interface as a nested-keyed interface, which makes adding optional arguments in the future easier (see doc updates in the first patch). - Modified the commit message to reflect changes and added a timeout argument as a suggested possible extension - Return -EAGAIN if the kernel fails to reclaim the full requested amount. --- Shakeel Butt (1): memcg: introduce per-memcg reclaim interface Yosry Ahmed (3): selftests: cgroup: return -errno from cg_read()/cg_write() on failure selftests: cgroup: fix alloc_anon_noexit() instantly freeing memory selftests: cgroup: add a selftest for memory.reclaim Documentation/admin-guide/cgroup-v2.rst | 21 ++++ mm/memcontrol.c | 45 +++++++ tools/testing/selftests/cgroup/cgroup_util.c | 44 +++---- .../selftests/cgroup/test_memcontrol.c | 114 +++++++++++++++++- 4 files changed, 197 insertions(+), 27 deletions(-) -- 2.36.0.rc2.479.g8af0fa9b8e-goog