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 CAA27CCD185 for ; Mon, 13 Oct 2025 20:33:20 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2C5038E0075; Mon, 13 Oct 2025 16:33:20 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 29C248E0036; Mon, 13 Oct 2025 16:33:20 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1B27A8E0075; Mon, 13 Oct 2025 16:33:20 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 08A2A8E0036 for ; Mon, 13 Oct 2025 16:33:20 -0400 (EDT) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id C9F6111A7B1 for ; Mon, 13 Oct 2025 20:33:19 +0000 (UTC) X-FDA: 83994240918.27.B0763E9 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf26.hostedemail.com (Postfix) with ESMTP id 5202E140005 for ; Mon, 13 Oct 2025 20:33:18 +0000 (UTC) Authentication-Results: imf26.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=nr0fuxx7; spf=pass (imf26.hostedemail.com: domain of frederic@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=frederic@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1760387598; 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:in-reply-to:references:references:dkim-signature; bh=zb8BTW0f0Ao7/Wihg46QLJz7+p0vPQEQj1GFgHqt1bw=; b=xoM4RZxmQUn6pRlGRTm5cdThDALUmH6w8y4K2y6FDZx7dv4BmCTr0YedLz4tjDFjb2d7Gs +QfQ5GLm2fYxSBzd3vmMC6aAPRKORVJUq/qHWgNOWzyNJFAr4uiM08a+aW//CnniqWYlTD 9Ma3wx0AsaG4YK6edkB1tAzKESwbT2o= ARC-Authentication-Results: i=1; imf26.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=nr0fuxx7; spf=pass (imf26.hostedemail.com: domain of frederic@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=frederic@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1760387598; a=rsa-sha256; cv=none; b=gKovHAX/xwv58gGpqcwSKsWsfoIycQtRdvzYDZMbWO+89n9XhhgUy7ovtOOI/qrnnfUaVR NJzPwWwYQSiCo9wjQ/tX42g1HPVmP/FKIu/voklV252I4q+7NmoIRWljXzmxXm7Kx4Ly/H YcF1LXYRZi3DsslbBGg51dv6dYr5gPU= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id BE6CE602DC; Mon, 13 Oct 2025 20:33:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C82C6C4CEE7; Mon, 13 Oct 2025 20:33:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1760387597; bh=069wMqK9bF6D74YIJY8nZAw2J7YjllAfy3UAu+j/YUM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nr0fuxx7FtPY7fJU5ejEizbK2Fmcqu1mfEn+GquUnw3jwyvpq3Y9tKq2/T8KUk6RR JZhoiumkpvbJpazECFQNPowuPt0W4T85Ke7okzvxlIm2MuwLxGoEXBZNa3j1904pYv ox/vfzysa35T1SZh5zfwrBb66qwCYUwvfg02dUiHd1kBSvqOuXOjgwiEREbkpvWfRH DZPrxKv8Kag1TTXWVLbDwL5Kk8ngthFxiKL93tBh2gRoCOZY8reOajnxkT1t3cg6d6 kUuv9Evj4Q1a3xNZ+yJ2C8CeeZhGjAyplt6wurS9Zo0IGEgcgrZYbW/RJw9DOo2nyq iNjjbjUDB8ZKw== From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , =?UTF-8?q?Michal=20Koutn=C3=BD?= , Andrew Morton , Bjorn Helgaas , Catalin Marinas , Danilo Krummrich , "David S . Miller" , Eric Dumazet , Gabriele Monaco , Greg Kroah-Hartman , Ingo Molnar , Jakub Kicinski , Jens Axboe , Johannes Weiner , Lai Jiangshan , Marco Crivellari , Michal Hocko , Muchun Song , Paolo Abeni , Peter Zijlstra , Phil Auld , "Rafael J . Wysocki" , Roman Gushchin , Shakeel Butt , Simon Horman , Tejun Heo , Thomas Gleixner , Vlastimil Babka , Waiman Long , Will Deacon , cgroups@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-block@vger.kernel.org, linux-mm@kvack.org, linux-pci@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH 10/33] cpu: Provide lockdep check for CPU hotplug lock write-held Date: Mon, 13 Oct 2025 22:31:23 +0200 Message-ID: <20251013203146.10162-11-frederic@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251013203146.10162-1-frederic@kernel.org> References: <20251013203146.10162-1-frederic@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 5202E140005 X-Rspamd-Server: rspam11 X-Rspam-User: X-Stat-Signature: nr7e8hos8pg96168f6ojk7sjwhes5dwi X-HE-Tag: 1760387598-460581 X-HE-Meta: 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 CWw== 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: cpuset modifies partitions, including isolated, while holding the cpu hotplug lock read-held. This means that write-holding the CPU hotplug lock is safe to synchronize against housekeeping cpumask changes. Provide a lockdep check to validate that. Signed-off-by: Frederic Weisbecker --- include/linux/cpuhplock.h | 1 + include/linux/percpu-rwsem.h | 1 + kernel/cpu.c | 5 +++++ 3 files changed, 7 insertions(+) diff --git a/include/linux/cpuhplock.h b/include/linux/cpuhplock.h index f7aa20f62b87..286b3ab92e15 100644 --- a/include/linux/cpuhplock.h +++ b/include/linux/cpuhplock.h @@ -13,6 +13,7 @@ struct device; extern int lockdep_is_cpus_held(void); +extern int lockdep_is_cpus_write_held(void); #ifdef CONFIG_HOTPLUG_CPU void cpus_write_lock(void); diff --git a/include/linux/percpu-rwsem.h b/include/linux/percpu-rwsem.h index 288f5235649a..c8cb010d655e 100644 --- a/include/linux/percpu-rwsem.h +++ b/include/linux/percpu-rwsem.h @@ -161,6 +161,7 @@ extern void percpu_free_rwsem(struct percpu_rw_semaphore *); __percpu_init_rwsem(sem, #sem, &rwsem_key); \ }) +#define percpu_rwsem_is_write_held(sem) lockdep_is_held_type(sem, 0) #define percpu_rwsem_is_held(sem) lockdep_is_held(sem) #define percpu_rwsem_assert_held(sem) lockdep_assert_held(sem) diff --git a/kernel/cpu.c b/kernel/cpu.c index 453a806af2ee..3b0443f7c486 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -534,6 +534,11 @@ int lockdep_is_cpus_held(void) { return percpu_rwsem_is_held(&cpu_hotplug_lock); } + +int lockdep_is_cpus_write_held(void) +{ + return percpu_rwsem_is_write_held(&cpu_hotplug_lock); +} #endif static void lockdep_acquire_cpus_lock(void) -- 2.51.0