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 78D8831327D; Tue, 13 Jan 2026 19:48:40 +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=1768333722; cv=none; b=sD4jY7aTV/uHEfbugQZ/3naZWFGvVb5/ecHzLwz/ukdpov9+/xQHHnj0kmy8lP4SJyqyOv0L0kdIR+QzzNTIXHXnn64qq5sQ2dpq7BMxvUj75Ggdlag5usrcLqbbXgbPNXl+O80sNwFa1Vee7Hn3x49eZ+xhWv/vwttWvzR2nkQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768333722; c=relaxed/simple; bh=bTp2Vjo4mw/wCtFQXi3331QEgeDTFtRFmfRf0623Zr4=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=lvkulqr6iTZ5cBmKHB/xwfJxhl4H7a/UlrXhCh/cW6VQGs9CMpbQPsyn8FZR/dB17m+UILa0LKE+WhN2RWBNAa60yH+bVL6IECgW9pgMG0LNepJOKW9yfYezOLBb8pHzCmWP6TaAXc8Zi6iIbSpv0sctkII3hPsXArd2X72efYU= 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=Y7Irkn5S; 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="Y7Irkn5S" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=efficios.com; s=smtpout1; t=1768333719; bh=FnQ6Xj9eoyZHqA1dE1GyFR6lhfMRam/O2mY67l2o+yY=; h=From:To:Cc:Subject:Date:From; b=Y7Irkn5SAfMbS6XllRAOy38YzIKPePFRJxrmK5s/LlwoBiKjexTQsXLqkDvG4V/H9 XlrU7L6s6UHwIbnKcoEST9xs24ZMEBbAksgKDYxi6O+hcFqU1Gdzlj5y31k28IQHbX LSTeK5oD4u4tz180kv1jIN6Nh7BtJKTqyx4GNmd6aYsvBQ9I42SFWhZCF3VuNgHKuo eQCrVk3Yh3G0omKKLElaM87Jf/Kh9jNEXWiZG2vhooOzVy6tD5jYEWxhAQrNQDaJGd C5qtL6gUYat8Id5+6CNaBnkKszN5bR+71dNi7CBQBa8h0rhL6/ImQHZc5m4VNK0LcF hNSfuGwcinaKA== Received: from thinkos.internal.efficios.com (mtl.efficios.com [216.120.195.104]) by smtpout.efficios.com (Postfix) with ESMTPSA id 4drKYg2L7PzlTP; Tue, 13 Jan 2026 14:48:39 -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, stable@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Yu Zhao , Roman Gushchin , Mateusz Guzik , Matthew Wilcox , Baolin Wang , Aboorva Devarajan Subject: [PATCH v1 0/1] mm: Fix OOM killer and proc stats inaccuracy on large many-core systems Date: Tue, 13 Jan 2026 14:47:33 -0500 Message-Id: <20260113194734.28983-1-mathieu.desnoyers@efficios.com> X-Mailer: git-send-email 2.39.5 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 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: stable@vger.kernel.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 (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