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 A261B4FC35A; Mon, 19 Oct 2026 13:10:01 +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=1792415402; cv=none; b=ocxoicaVJdXdyrLrC+qk2ia0zcdpSjoEhv1ZUOaF99RQTgsvjPiuU1EH4fxwFHGLiNdOA/Ly5qnCzpvBqNVQlpVoJ5Rs7MMl6E3pA+e4jzskDcSmHFyWRZ7Iv9b3jLW6nKZg92jPY7LB1WtOdDQU71JewUfudzI9pRyrBKFl/Pw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792415402; c=relaxed/simple; bh=+FVcX8diseZGGhX2/sAOON5TiO6ws1KZs4OjOfONp/0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rHJCS6NtIe7jnmC3QCiMnIkvHh9riugJ0Dtc4APtbqu3DLzHQ9tD8RVdFjjNXbZ5nNPXvvD+iT+KAbSdMdNHdlo2YG6uHocwppBm/mPZt2GJWJJRSSK+7lYHTaTbwBK9MFlfYG6wAlXvpEZkJ7M3G/Ur1v8ojgSkMTfTAxwbOrA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VmqdzGiC; 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="VmqdzGiC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 06C471F000C5; Mon, 19 Oct 2026 13:09:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792415401; bh=ViPzMqMMtYsXD2twtgRR0dhAxzp9lQPh6+izbO2fRX0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=VmqdzGiCKgvstUEqVR2BglPOe5LKWWO9W9V/oXmhCRIV5E0DJnZJloDgfjzQWeNTy ChOBZ4eOFyPHTgN0pgLEBHSaSIwxiCQwtN0OOzHuUCbf+B82vPlbeof1hXjI3Ub+fz /Ej1WvwxSNpggi/xEQ8ehQyqE9OG1ZnPDhy/PrNPowdGY0Rt8X5BLWXX6MaOGdVZ3Z clXvyx47u2RFDip8O21nOI2lnpyYjO7Pu+E2mZJ+lz9/tKu2ksklUKrOPTvQgmJy+8 HNGUTfOR5kxWQ8kASR5kF2b0LwjfIwc3HorGrfIYtMxOV2ctgl5KV+h+0r/Ml7phZx eItNbsi+dSV+g== From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Marco Crivellari , Mark Rutland , Peter Zijlstra , Phil Auld , Thomas Gleixner , Waiman Long , Will Deacon , linux-arm-kernel@lists.infradead.org, linux-perf-users@vger.kernel.org Subject: [RFC PATCH 19/49] perf/arm_pmu: Move CPUHP_AP_PERF_ARM_STARTING post stop_machine() Date: Mon, 19 Oct 2026 15:08:26 +0200 Message-ID: <20261019130856.49711-20-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-perf-users@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 just disables the IRQs for each PMUs, which shouldn't expose any specific race while other CPUs are running. 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 7d7e2d1eda9b..95cc6655cf7b 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_ARM_ACPI_STARTING); + enum cpuhp_state target = max((int)st->target, CPUHP_AP_PERF_ARM_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_ARM_ACPI_STARTING); + WARN_ON(st->state != CPUHP_AP_PERF_ARM_STARTING); /* * Invoke the former CPU_DYING callbacks. DYING must not fail! */ -- 2.53.0