[PATCH v2 0/2] mm, memcg: fix memory.peak reset clobbering other fds' watermark

Ridong <[email protected]> Fri, 7 Aug 2026 16:59:58 +0800
Newsgroups org.kernel.vger.cgroups,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
From: Ridong Chen <[email protected]>

Two fixes for the per-fd memory.peak / memory.swap.peak handlers added in
c6f53ed8f213. Each open fd reads back max(its own value, the shared
local_watermark), and both bugs live in that scheme.

---

Changes since v1 [1]:
 - New patch 1: hold peaks_lock in the peak readers (Sashiko).
 - Patch 2: floor the peers with max(usage, local_watermark), mirroring
   peak_show(), and skip the writing fd (Johannes Weiner).

[1] https://lore.kernel.org/all/[email protected]/

Ridong Chen (2):
  memcg: acquire peaks_lock when reading memory.peak
  mm, memcg: fix memory.peak reset clobbering other fds' watermark

 mm/memcontrol.c | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

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2.34.1