From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 61C814F96BE for ; Mon, 19 Oct 2026 13:10:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792415460; cv=none; b=QZmBgWEMe+IqbYETiNmyrZDJ0zk2sVYkEG4yndKSWvGBU2TLClOLoMMX+2eK7QkSfl2QqTGgNsjrjFP7ERsr3gvR+s1EE3r32HD5uW/dLLLrwoVvBLA22aura64jd0X/jJGTO+Xv1fyiWsUpx16lRton1BhfZe1qfRXekgosiqA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792415460; c=relaxed/simple; bh=9nBbjqqFe4SOeRSjmDyLFruaCTKLRTDfItgFOQXxDiw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=AUdW6OFDuK+LMNUJSIK5mosUO8CfBp78d9XvVrqzq51au8e3zk/y6HdhHnwChuxK+7aChbDUlfARQjbyhK5dh7zySeP+AGIdWoFi0+2nooovQlKq4abaL6XcbwVb6PdXOqCDoH07jY99niSAigFFMyOjTCNyO316MIT4Ki65Fa0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UYYhVV8D; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UYYhVV8D" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E045C1F000C7; Mon, 19 Oct 2026 13:10:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792415459; bh=sQ4wV/CtE843TsaJyn8NdxjU1otXO+lUSiOR4zR4+6M=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=UYYhVV8DRwSugxc4w9TTb0o/rWDNMV80kuTV12atH3lBKClROKPctzL7bZd9hdFgv PfWhK+tqVWRVA7qQkMj7dT0dnWY0hXHvfIgvLn8S4zOeBl+0okkfv7UJGsT9ZK+x6J U3DvNv+Ss6hZiw4sprDxO9KEs6F6axzzZ84A2hpzBy9wwYEzr/G1ANlH5AHofU6Tiz Uy5kF15EDPm7FE+G0xVDrufXD7ZER+IyTbn1RCyhJvJHjP5VxCxTbulIjhEpKg1U1Q KtgogEtCjb3O4RgR5JeRmDA4jgOCJgFdhH96o7W3KYEtrATjxWWPIzXGacLidHxxvZ 5imvBcCnwnNnQ== From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Marco Crivellari , Peter Zijlstra , Phil Auld , Russell King , Stefano Stabellini , Thomas Gleixner , Waiman Long , linux-arm-kernel@lists.infradead.org, xen-devel@lists.xenproject.org Subject: [RFC PATCH 41/49] ARM: xen: Move CPUHP_AP_ARM_XEN_STARTING post stop_machine() Date: Mon, 19 Oct 2026 15:08:48 +0200 Message-ID: <20261019130856.49711-42-frederic@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261019130856.49711-1-frederic@kernel.org> References: <20261019130856.49711-1-frederic@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Between CPUHP_TEARDOWN_CPU and CPUHP_AP_OFFLINE, stop_machine executes all the teardown callbacks while stopping all CPUs in the system. This doesn't mix-up well with running RT or isolated tasks. In order to transition smoothly from global stop_machine to finer grained synchronization between teardown callbacks and the other CPUs, a new stop machine post function has been introduced to be executed after the main one with IRQs still disabled while other CPUs can exit stop_machine(). The teardown callback here simply performs IRQ disablement, which can run concurrently with other CPUs. Move it to post stop_machine() accordingly. Signed-off-by: Frederic Weisbecker --- kernel/cpu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/cpu.c b/kernel/cpu.c index bc06cb1f0282..8509c6377a61 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -1275,7 +1275,7 @@ void clear_tasks_mm_cpumask(int cpu) static int take_cpu_down(void *_param) { struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); - enum cpuhp_state target = max((int)st->target, CPUHP_AP_DUMMY_TIMER_STARTING); + enum cpuhp_state target = max((int)st->target, CPUHP_AP_ARM_XEN_STARTING); int err, cpu = smp_processor_id(); /* Ensure this CPU doesn't handle any more interrupts. */ @@ -1303,7 +1303,7 @@ static int take_cpu_down_post(void *_param) enum cpuhp_state target = max((int)st->target, CPUHP_AP_OFFLINE); int cpu = smp_processor_id(); - WARN_ON(st->state != CPUHP_AP_DUMMY_TIMER_STARTING); + WARN_ON(st->state != CPUHP_AP_ARM_XEN_STARTING); /* * Invoke the former CPU_DYING callbacks. DYING must not fail! */ -- 2.53.0