From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D571FD2F35C for ; Tue, 13 Jan 2026 19:48:42 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 336006B0005; Tue, 13 Jan 2026 14:48:42 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 30D286B0089; Tue, 13 Jan 2026 14:48:42 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 239E26B008A; Tue, 13 Jan 2026 14:48:42 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 0FD556B0005 for ; Tue, 13 Jan 2026 14:48:42 -0500 (EST) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id D29BA160286 for ; Tue, 13 Jan 2026 19:48:41 +0000 (UTC) X-FDA: 84327978042.14.A543780 Received: from smtpout.efficios.com (smtpout.efficios.com [158.69.130.18]) by imf04.hostedemail.com (Postfix) with ESMTP id 472D140009 for ; Tue, 13 Jan 2026 19:48:40 +0000 (UTC) Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=efficios.com header.s=smtpout1 header.b=Y7Irkn5S; dmarc=pass (policy=none) header.from=efficios.com; spf=pass (imf04.hostedemail.com: domain of mathieu.desnoyers@efficios.com designates 158.69.130.18 as permitted sender) smtp.mailfrom=mathieu.desnoyers@efficios.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1768333720; a=rsa-sha256; cv=none; b=qrs/1BpYj8VKVQQ2QOG1e2HBDRh3SEnTLT39I/krbizAlmV8N6Qh4FTgip4apsNsLbQ/wL hle/MskhSKx048QustpY5K3YUaSrcj+mtiA0k7x7qs8P/2BnKm5HvvwW7ndAWSplXMQXG8 xN4Po+E7Ay0sA0Z1b7jL6i/xDBVIxSQ= ARC-Authentication-Results: i=1; imf04.hostedemail.com; dkim=pass header.d=efficios.com header.s=smtpout1 header.b=Y7Irkn5S; dmarc=pass (policy=none) header.from=efficios.com; spf=pass (imf04.hostedemail.com: domain of mathieu.desnoyers@efficios.com designates 158.69.130.18 as permitted sender) smtp.mailfrom=mathieu.desnoyers@efficios.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1768333720; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:references:dkim-signature; bh=FnQ6Xj9eoyZHqA1dE1GyFR6lhfMRam/O2mY67l2o+yY=; b=qInWemvDRb9f/3vfoND9c/v/I5aUpcswpTh7NMr9pE8hNEgFpfUcGyM9KozKYZ3Nbf6iym RW3zOOxfkNglf5DKP5K/QyGHl4ynI9b7u0HXQf4G89a8ytsy+TFRVWUrVBbYft2IsoAQOS VmChmd6KXC1ukhiEGXOrLFlN4l/scM4= 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 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Stat-Signature: 41xegg94wtkyxyw53g48adsj7dg1134g X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 472D140009 X-HE-Tag: 1768333720-503052 X-HE-Meta: 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 eVYi5WaJ 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 hMdca5pU RQTkNtMwOz0wRZERkOMSkfwbeFuw5FTLKAKRIUdVBEsEVZ/LN05h3ns99DhyIZieTGhFcxUWaJZW/tGIRJZWHA== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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