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 E0306FD8FF9 for ; Thu, 26 Feb 2026 18:27:03 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1769A6B016C; Thu, 26 Feb 2026 13:27:00 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0B99E6B0172; Thu, 26 Feb 2026 13:26:59 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E61266B0173; Thu, 26 Feb 2026 13:26:59 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id D35AF6B016C for ; Thu, 26 Feb 2026 13:26:59 -0500 (EST) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 9415958825 for ; Thu, 26 Feb 2026 18:26:59 +0000 (UTC) X-FDA: 84487439358.27.3609ECE Received: from mail.ilvokhin.com (mail.ilvokhin.com [178.62.254.231]) by imf13.hostedemail.com (Postfix) with ESMTP id D6A4120003 for ; Thu, 26 Feb 2026 18:26:57 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=ilvokhin.com header.s=mail header.b=OXH8f7Fl; spf=pass (imf13.hostedemail.com: domain of d@ilvokhin.com designates 178.62.254.231 as permitted sender) smtp.mailfrom=d@ilvokhin.com; dmarc=pass (policy=reject) header.from=ilvokhin.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1772130418; 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=LlCjj+3UcXvXvqd5PfGg5q5chZ1QMHNerBnuWirnbHA=; b=KlQN4mqUYdegs2GMHWazSfuDv5K5rTBrB+SopTSg7UnyFsdafBkiMl4mJ0hp+FPsoUpc6c KfFEwwp4Vxto0beIrX+UIacXlJV1QXRzZkLp+q7FIKF1oQEEoNcEy6kIUrmhJdo/TbH/1D GjmZkn7uEoZN4sUM51uixQBo71Kq430= ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=pass header.d=ilvokhin.com header.s=mail header.b=OXH8f7Fl; spf=pass (imf13.hostedemail.com: domain of d@ilvokhin.com designates 178.62.254.231 as permitted sender) smtp.mailfrom=d@ilvokhin.com; dmarc=pass (policy=reject) header.from=ilvokhin.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1772130418; a=rsa-sha256; cv=none; b=heCixD0lEVF/r232Q1NXeGxcJ9mg+C3/QpRld+L6Dzp9lgKcAoc15qd9J0oHR9/RF1k6hy mLwq2NkGPdXzpU12s0KJkURxq6OBFRcZpr00FYJv2Mt1rYwq39wRAbhzH2Lwm85qnnPpzv C18pQzjCaD25BOFTRKE6U4kD4EQpyHc= Received: from localhost.localdomain (shell.ilvokhin.com [138.68.190.75]) (Authenticated sender: d@ilvokhin.com) by mail.ilvokhin.com (Postfix) with ESMTPSA id 34E3CB2CD9; Thu, 26 Feb 2026 18:26:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ilvokhin.com; s=mail; t=1772130414; bh=LlCjj+3UcXvXvqd5PfGg5q5chZ1QMHNerBnuWirnbHA=; h=From:To:Cc:Subject:Date; b=OXH8f7FlOnxRA+eanQJnKn/eZc8rUSUG5RNK9MOQAg1wdyf1WUHzZIzq119NaxEQg ITICJ0B0MOIR43D4yzTWI/bnDjH040u5352TQ9ixNzCkSMxAM9ZJRitpZ2GIFMg3B9 cDltXdx1xa7+0bG+P6hLsjU6iLNzNFb0TvLgrM18= From: Dmitry Ilvokhin To: Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Axel Rasmussen , Yuanchu Xie , Wei Xu , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Brendan Jackman , Johannes Weiner , Zi Yan , Oscar Salvador , Qi Zheng , Shakeel Butt Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, linux-cxl@vger.kernel.org, kernel-team@meta.com, Benjamin Cheatham , Dmitry Ilvokhin Subject: [PATCH v3 0/5] mm: zone lock tracepoint instrumentation Date: Thu, 26 Feb 2026 18:26:17 +0000 Message-ID: X-Mailer: git-send-email 2.53.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Stat-Signature: wekiyce8kbi5ydxtk4wemnpweue8pphb X-Rspamd-Queue-Id: D6A4120003 X-Rspamd-Server: rspam10 X-HE-Tag: 1772130417-266631 X-HE-Meta: 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 lT3kSKPM CfYyeoxNxb3ExdKpoRDU2xG0WTBAy9Vx55AtGj2PX7voXCAoW249DIAYjl5SXVLw5VVDaDj8Sr+kR0FnfNYpr/m4lOBj2B8eKkJgYaA6yRL7qldygi40S6iyCca8f0objK9Yv62OUdrYBGcQIAuHU9iVGg6V8yNMMUd1ezO5JTWd9dCV+82WqiT3XpQAhM5tLQ7ZTN4vXg4W6bG1AMQ9GAavAQG4g4zVBrPp2dpTKDEDwpUmHlYl/V9anU+HuytlclhpTD82SNqE5URo= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Zone lock contention can significantly impact allocation and reclaim latency, as it is a central synchronization point in the page allocator and reclaim paths. Improved visibility into its behavior is therefore important for diagnosing performance issues in memory-intensive workloads. On some production workloads at Meta, we have observed noticeable zone lock contention. Deeper analysis of lock holders and waiters is currently difficult with existing instrumentation. While generic lock contention_begin/contention_end tracepoints cover the slow path, they do not provide sufficient visibility into lock hold times. In particular, the lack of a release-side event makes it difficult to identify long lock holders and correlate them with waiters. As a result, distinguishing between short bursts of contention and pathological long hold times requires additional instrumentation. This patch series adds dedicated tracepoint instrumentation to zone lock, following the existing mmap_lock tracing model. The goal is to enable detailed holder/waiter analysis and lock hold time measurements without affecting the fast path when tracing is disabled. The series is structured as follows: 1. Introduce zone lock wrappers. 2. Mechanically convert zone lock users to the wrappers. 3. Convert compaction to use the wrappers (requires minor restructuring of compact_lock_irqsave()). 4. Rename zone->lock to zone->_lock. 5. Add zone lock tracepoints. The tracepoints are added via lightweight inline helpers in the wrappers. When tracing is disabled, the fast path remains unchanged. Changes in v3: - Split compact_lock_irqsave() to compact_zone_lock_irqsave() and compact_lruvec_lock_irqsave(). - Rename zone->lock to zone->_lock. Changes in v2: - Move mecanical changes from mm/compaction.c to different commit. - Removed compact_do_zone_trylock() and compact_do_raw_trylock_irqsave(). v1: https://lore.kernel.org/all/cover.1770821420.git.d@ilvokhin.com/ v2: https://lore.kernel.org/all/cover.1772030186.git.d@ilvokhin.com/ Dmitry Ilvokhin (5): mm: introduce zone lock wrappers mm: convert zone lock users to wrappers mm: convert compaction to zone lock wrappers mm: rename zone->lock to zone->_lock mm: add tracepoints for zone lock MAINTAINERS | 3 + include/linux/mmzone.h | 7 ++- include/linux/zone_lock.h | 100 +++++++++++++++++++++++++++++++ include/trace/events/zone_lock.h | 64 ++++++++++++++++++++ mm/Makefile | 2 +- mm/compaction.c | 58 +++++++++++------- mm/internal.h | 2 +- mm/memory_hotplug.c | 9 +-- mm/mm_init.c | 3 +- mm/page_alloc.c | 89 +++++++++++++-------------- mm/page_isolation.c | 23 +++---- mm/page_owner.c | 2 +- mm/page_reporting.c | 13 ++-- mm/show_mem.c | 5 +- mm/vmscan.c | 5 +- mm/vmstat.c | 9 +-- mm/zone_lock.c | 31 ++++++++++ 17 files changed, 326 insertions(+), 99 deletions(-) create mode 100644 include/linux/zone_lock.h create mode 100644 include/trace/events/zone_lock.h create mode 100644 mm/zone_lock.c -- 2.47.3