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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id EA8F8CCF2DB for ; Mon, 19 Oct 2026 13:10:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=JfFnHIQswXgjAATM2WjaIntcOReaKHtse3Er3j4flI4=; b=TXKikrOfklpn5Lkihfi/eaXR7I Yq9al61IhOEZKAptrl8uGd/5AXY7cmT83DlNM1Q+d5WaIp5nlH2m6j1AuA0nqpJ/KbU+IffrN/LfR SwiZOCVJ5RJcuk1JUUKEKylwKfjZxsxFv4GhNE5XUEklDRNdipsGKLO8FAMa6nCmoqQmtO9NX3M8+ hWSQ/LnHTfKhjPfsBMLj+T/BuAnskBakZWCsRFZX9U0wnQYBt+avC7pTEhJd4Vsi5fCkW/c4aKybV Dq9lsI8KW7N9/cDX+/p3UcqBTq2Yr3RfkmIUKKSgVW2wTr+bAXr+5qxlmhzmAxSfdtNe5fN6hj+wq zWmhiYFA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xIn7x-00000007TAa-2uxx; Mon, 19 Oct 2026 13:10:09 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xIn7w-00000007T9I-2Fdn for linux-arm-kernel@lists.infradead.org; Mon, 19 Oct 2026 13:10:08 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id E181A4183A; Mon, 19 Oct 2026 13:10:07 +0000 (UTC) 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> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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