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 D0CCC4F5E1B for ; Mon, 19 Oct 2026 13:09:56 +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=1792415398; cv=none; b=bkWu9KL6pmJ+XAFKWCYqOFLD3M3hpEkZVIkCwyU+Lbh+dQ7o96LM/0RZSzYGsoUo9RwAaP2msBIFRlfwWRw49VWYmzaI+N1PSt0hyDBrikZhs/GMqFaKTJJ0u8f1FohxF0ycetUEAze6wGjwR0Q65CIhs1TzWUw068R/S28lrxs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792415398; c=relaxed/simple; bh=9+Utw6OtqfpySTyHCDh5VQD2KcJIi5/w2OzUmq3jTYU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=EN+Ayl0e18/TdkWH5QLvF+8gOAwXj4DEZ5MZgWQ45Or/C4ecM4/57aQXcFs2faJAcE4wyoGSi5F6Y/5gD405PxDAaDizUQoT4rEBXE0PatvxrR2IyL310/Q+feqKZ9wDp+x5if2MwLqE3gHKOIFR4pJ3xVKkfNzj85FzQBOVmNg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=n3LxuVl8; 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="n3LxuVl8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7790E1F000C5; Mon, 19 Oct 2026 13:09:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792415396; bh=tVzuQgyRSMcF1cPObbB3KELngDUQbdY4OVt3CdDmVuw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=n3LxuVl8s9roRBlbS2hHlqvUnSN8pHgIXJAetNqTKL08/I3LtNCjYSAAXpMzDdaCH v0AubukCKCs8tN6qp/d3N4xHqiCrKG2wRTE+cl7JXP4x/g+0/Y/9IiFP4WP/b+XMQC PTJt+U5ZyjjzevN1Xoy61bZEacx6C8hX+wJKqw79/8mpwDbwAaZw1P+XOSqYtiPwLx 5b0IHf0u96+sZTH6mZLoZ5tZibz+oEOzJUmKuyiRaH6o6ujmNjCkhpFPzwSeuVRZml U+KBpUE12sCqulu2uwtahhQYdRCpGMdFelYx/XghQ1s8B8YX+rkjnhZKL1ucT5bauL 3ZMiFwqHO4fTg== From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Marco Crivellari , Peter Zijlstra , Phil Auld , Russell King , Thomas Gleixner , Waiman Long , linux-arm-kernel@lists.infradead.org Subject: [RFC PATCH 17/49] ARM: vfp: Move CPUHP_AP_ARM_VFP_STARTING post stop_machine() Date: Mon, 19 Oct 2026 15:08:24 +0200 Message-ID: <20261019130856.49711-18-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 only removes the local VFP state which is never accessed remotely. As such it 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 c20a822df803..b7f5d0683ff7 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_PERF_XTENSA_STARTING); + enum cpuhp_state target = max((int)st->target, CPUHP_AP_ARM_VFP_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_PERF_XTENSA_STARTING); + WARN_ON(st->state != CPUHP_AP_ARM_VFP_STARTING); /* * Invoke the former CPU_DYING callbacks. DYING must not fail! */ -- 2.53.0