Thread (10 messages) flat view 10 messages, 4 authors, 2026-01-14
STALE238d

[PATCH v1 0/1] mm: Fix OOM killer and proc stats inaccuracy on large many-core systems

From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: 2026-01-13 19:48:40
Also in: linux-mm, lkml, stable

Hi Andrew,

This patch modifies the OOM killer and all proc RSS stats to use the
precise for-each-possible-cpu sum to fix the inaccuracy issues. This
approach was suggested by Michal Hocko as a straightforward fix for the
inaccuracy issue by using more precise (but slower) RSS stats sum.

With this, the hierarchical per-cpu counters become a simple
optimization rather than a bug fix. I will post a new version
of the HPCC soon which will be based on this patch.

Feedback is welcome!

Thanks,

Mathieu

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <redacted>
Cc: Martin Liu <redacted>
Cc: David Rientjes <rientjes@google.com>
Cc: christian.koenig@amd.com
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: SeongJae Park <sj@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Sweet Tea Dorminy <redacted>
Cc: Lorenzo Stoakes <redacted>
Cc: "Liam R . Howlett" <redacted>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <redacted>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Wei Yang <redacted>
Cc: David Hildenbrand <redacted>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-mm@kvack.org
Cc: stable@vger.kernel.org
Cc: linux-trace-kernel@vger.kernel.org
Cc: Yu Zhao <redacted>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Mateusz Guzik <redacted>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Aboorva Devarajan <redacted>

Mathieu Desnoyers (1):
  mm: Fix OOM killer and proc stats inaccuracy on large many-core
    systems

 fs/proc/task_mmu.c | 14 +++++++-------
 include/linux/mm.h |  5 -----
 2 files changed, 7 insertions(+), 12 deletions(-)

-- 
2.39.5
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