[PATCH v5 0/4] memcg: introduce per-memcg proactive reclaim

From: Yosry Ahmed
Date: Mon Apr 25 2022 - 15:01:15 EST

This patch series adds a memory.reclaim proactive reclaim interface.
The rationale behind the interface and how it works are in the first


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:
- 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.

- 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


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(-)