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 DF3AE4FD263 for ; Mon, 19 Oct 2026 13:10:07 +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=1792415408; cv=none; b=brAi6WYrOnqV4R8b66B6JISMUAgpgnJnBbvrC8eozcJKCjxoL8J3SmNF9GKKV/6BxYhovQbIEmFAT0ko1LmTlTzE5/Z/h89wV7uFJt+UKv+RRB8ZFf1ORfsNgM8sGVEHMcWo6shJBeym6xS1cVIlddF3rNQsU9TPx+KDEwWfiP4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792415408; c=relaxed/simple; bh=i2RWjea9mxD9svVgNnDGLvHTA219cVzxecBM3mzB0v4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BWz4VeNMEx8ymYhS6EMtke1wvvyxTAbTdTTXhuKAXKGvZKvK0O2oZVBcZjgfgjxbV8RpO0MwYrczIYbWn8wDq12wXH5Wc4Q4JWKnLE1pxHig6pLAAoN1j9mZ2FJ2GSafQD7EsM9e5a7xy0d4vcOYxSIXmyaHGh44STjW7qFsOok= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GFLzlrrN; 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="GFLzlrrN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E76411F000C5; Mon, 19 Oct 2026 13:10:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792415407; bh=JfFnHIQswXgjAATM2WjaIntcOReaKHtse3Er3j4flI4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=GFLzlrrNT+70mA4GzKfeMRQNoaifWC7yKQlW5LhmrYCpOt1NItlopgVdL/5SX/es9 /C/UIhXQso0AN0oXVTdy6lYWAwYo0Rj0eeZRc7dIIBl4582zR2YkinIEZbOi8vfVkr zrKh8N1yM5Ru1kk8qPkX25+c/2rZnQ7zNjNRxpCSqV5RJxGzl9R98lGN8TOB4Y3gwP DWwQrHPF6LFcRVippaz1QQi+d/lfBH97dumtl7sHIHuY62jUrSanx9ELq2EWTibXso 4Ll1EIXdq2bIMe0odF7DGEo5VskUQbDhCDzsh6E4noYg/Su3q38rZyYGZ/rVuxKYtQ eZGgCLlAMnKwA== 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 21/49] ARM: l2c: Move CPUHP_AP_ARM_L2X0_STARTING post stop_machine() Date: Mon, 19 Oct 2026 15:08:28 +0200 Message-ID: <20261019130856.49711-22-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 disables the L1/L2 cache prefetch and the write full line of zeros mode. These operations should only impact the outgoing CPU and 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 c69a265e4383..c08ef67e3499 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_RISCV_STARTING); + enum cpuhp_state target = max((int)st->target, CPUHP_AP_ARM_L2X0_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_RISCV_STARTING); + WARN_ON(st->state != CPUHP_AP_ARM_L2X0_STARTING); /* * Invoke the former CPU_DYING callbacks. DYING must not fail! */ -- 2.53.0