[PATCH v3 0/2] mm/mglru: fix ineffective memory protection for non-kswapd reclaim

[Ridong Chen <ridong.chen@linux.dev>]

From: Ridong Chen <chenridong@xiaomi.com>

For MGLRU, memory.min/low is not honored during non-kswapd global
reclaim (global direct reclaim and root-level memory.reclaim), because
these paths shrink memcgs using stale effective protection (emin/elow).

Patch 2 is the actual fix. Patch 1 is a prerequisite: an integer overflow
in effective_protection(), spotted by the sashiko review tool, which
patch 2's new caller would also be exposed to.

---

v3:
- Per Barry Song's review comments

v2:
- Fix an issue caused by non-atomic read races in patch 1 [1]

[1] https://sashiko.dev/#/patchset/20260828092432.1257917-1-ridong.chen@linux.dev?part=1

Ridong Chen (2):
  mm/page_counter: avoid integer overflow in effective_protection()
  mm/mglru: fix ineffective memory protection for non-kswapd reclaim

 include/linux/memcontrol.h | 10 +++++++++
 mm/memcontrol.c            | 45 ++++++++++++++++++++++++++++++++++++++
 mm/page_counter.c          | 19 +++++++++++-----
 mm/vmscan.c                |  8 ++++++-
 4 files changed, 75 insertions(+), 7 deletions(-)


base-commit: 32b6ef9a5d0eca44f9cd91f52f4faa89f145a0de
--
2.34.1