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 A551FCCF2DE for ; Mon, 19 Oct 2026 13:10:09 +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=ViPzMqMMtYsXD2twtgRR0dhAxzp9lQPh6+izbO2fRX0=; b=F4iYc4I+9XBv9JMH5w7jKjvdcy Mz1ql73Xr6hfdljsvNmSqa6YKhnunC2+GACY0H4+S4+HukeTHpLh8Mpo0NsiD6eu0nkHZqqtOqllE CloQryjrUBFEOYf9W7sFXNETTWXNIH/kIHNf2cM9nTqC/yRGz5hlv9k+/K5yxuGylkUVyXoAtDsIc hgNjp2fJ7tXZTV7fq2rHVlg98Et4chyS5pEWQCbQ3SgCnisGeipfP3sDNRVFlYTFk7a4BxrQWj5c+ maSg4FyUhDKaq60TsjjuS34RQDDexdLE6b4pON7LTUIRXIEn0YYY924BcD2WyBVICPChJNjoMvg0x /NYOnQ9w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xIn7r-00000007T6U-1WWF; Mon, 19 Oct 2026 13:10:03 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xIn7q-00000007T5K-0luH for linux-arm-kernel@lists.infradead.org; Mon, 19 Oct 2026 13:10:02 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 9E68360238; Mon, 19 Oct 2026 13:10:01 +0000 (UTC) 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> 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 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