From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout.efficios.com (smtpout.efficios.com [158.69.130.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7FDEF253958; Thu, 20 Nov 2025 21:09:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=158.69.130.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763672960; cv=none; b=VTZEIqjMGGeW5k8LuckeCRt6vQTLVHnLm4reL9Q0OyrzKMQ+6UG4BLmTngrC9OLu8vH0r3089zXuIfpsBn0Iuo5M2SYuj7xAmRq9rMxglZ78NE4dgkoOrsosfPtsTY4tzezIBnvD1msvBqDYei3Rq8qFBEM9XOpYMZ6bE7DxtFA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763672960; c=relaxed/simple; bh=mgovFCgOkXXcRXjBDmBlQa4nl6g3oS4T8VqX7baHTyA=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=VY0anHw0YMYV9O18KyStbSO2A7n/Q9JJRorJYkd6B/Ge1CSQGIHQlSrdoHpe/rVPdPyQa2lTDfahl+PygBXnx+g4DS0H46GZLZe/HZ2pSr/qdUeMlscvkjIleFy6h/yUTyBDZXCY2alZrCvsKxRArkGOwni1U0pOZMNGyonryB4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=efficios.com; spf=pass smtp.mailfrom=efficios.com; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b=lS1I1mgB; arc=none smtp.client-ip=158.69.130.18 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=efficios.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=efficios.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b="lS1I1mgB" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=efficios.com; s=smtpout1; t=1763672639; bh=v1+iPRnl2CJz3Y6EOfGCbzApG9MSnpiujyLXIhkhEIs=; h=From:To:Cc:Subject:Date:From; b=lS1I1mgB0/MTUHG/NX1LUQLm4Ho2ZFEsstTyaYZAyLg+9D/deFZSDJivA28INgblv 1mcpvlpEyNPURDN6SUqHhdxKbNDX/hEgwHS4BuerLMMdkFX5LX7mSj1ThpGoFqtjjn ZvKLuSlOgAAUbaC26H4+35DxTOWJ18U/eu+7IR5UM0jdv7u71jM9+e0FXF7Wdh0zLQ NVeUpxu4MsTPXHj/OHxGIqLnhMugepLBcjow/56yzarqtMtwd2AEErere5G21zBOOQ UaI3Xq8YEh34icjkknLAEawShi5wUPBpG+vhdwbazI47WYZkcnrP2esAebC/DDfbV0 4a6kGh75dNt1Q== Received: from thinkos.internal.efficios.com (mtl.efficios.com [216.120.195.104]) by smtpout.efficios.com (Postfix) with ESMTPSA id 4dC9nW5NGnzNVP; Thu, 20 Nov 2025 16:03:59 -0500 (EST) From: Mathieu Desnoyers To: Andrew Morton Cc: linux-kernel@vger.kernel.org, Mathieu Desnoyers , "Paul E. McKenney" , Steven Rostedt , Masami Hiramatsu , Dennis Zhou , Tejun Heo , Christoph Lameter , Martin Liu , David Rientjes , christian.koenig@amd.com, Shakeel Butt , SeongJae Park , Michal Hocko , Johannes Weiner , Sweet Tea Dorminy , Lorenzo Stoakes , "Liam R . Howlett" , Mike Rapoport , Suren Baghdasaryan , Vlastimil Babka , Christian Brauner , Wei Yang , David Hildenbrand , Miaohe Lin , Al Viro , linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, Yu Zhao , Roman Gushchin , Mateusz Guzik , Matthew Wilcox , Baolin Wang , Aboorva Devarajan Subject: [PATCH v9 0/2] mm: Fix OOM killer inaccuracy on large many-core systems Date: Thu, 20 Nov 2025 16:03:52 -0500 Message-Id: <20251120210354.1233994-1-mathieu.desnoyers@efficios.com> X-Mailer: git-send-email 2.39.5 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Introduce hierarchical per-cpu counters and use them for rss tracking to fix the per-mm RSS tracking which has become too inaccurate for OOM killer purposes on large many-core systems. The approach proposed here is to replace this by the hierarchical per-cpu counters, which bounds the inaccuracy based on the system topology with O(N*logN). Testing and feedback are welcome! Thanks, Mathieu Cc: Andrew Morton Cc: "Paul E. McKenney" Cc: Steven Rostedt Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Dennis Zhou Cc: Tejun Heo Cc: Christoph Lameter Cc: Martin Liu Cc: David Rientjes Cc: christian.koenig@amd.com Cc: Shakeel Butt Cc: SeongJae Park Cc: Michal Hocko Cc: Johannes Weiner Cc: Sweet Tea Dorminy Cc: Lorenzo Stoakes Cc: "Liam R . Howlett" Cc: Mike Rapoport Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Christian Brauner Cc: Wei Yang Cc: David Hildenbrand Cc: Miaohe Lin Cc: Al Viro Cc: linux-mm@kvack.org Cc: linux-trace-kernel@vger.kernel.org Cc: Yu Zhao Cc: Roman Gushchin Cc: Mateusz Guzik Cc: Matthew Wilcox Cc: Baolin Wang Cc: Aboorva Devarajan Mathieu Desnoyers (2): lib: Introduce hierarchical per-cpu counters mm: Fix OOM killer inaccuracy on large many-core systems include/linux/mm.h | 28 +- include/linux/mm_types.h | 4 +- include/linux/percpu_counter_tree.h | 239 +++++++++++++++ include/trace/events/kmem.h | 2 +- init/main.c | 2 + kernel/fork.c | 24 +- lib/Makefile | 1 + lib/percpu_counter_tree.c | 443 ++++++++++++++++++++++++++++ 8 files changed, 725 insertions(+), 18 deletions(-) create mode 100644 include/linux/percpu_counter_tree.h create mode 100644 lib/percpu_counter_tree.c -- 2.39.5