From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 83FC4606CBCC for ; Thu, 5 Nov 2026 16:32:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=GzAtZWJI; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=W+hHuRN0 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-Unsubscribe-Post: List-Owner; bh=u7ZwqjtzSR0o1QTyifWY7mPwVdBSMzMSz40FvvcurNg=; b=GzAtZWJIZfhK74 uPhpjtYKUQ0g8xx8OclUu+C+FoAtZ3DFex0MZy5uYXFN5vGn75TvT6ZyXLL3WUObeBz8VXAJu9pTb HkKTez1q8fUMcW/7ntGyiOZ3poJvT8l3nB3xHlSki9NZ5CqWdR/YKGw6od9JWsNpMChhJQcJSa/YR lY+HesgRMwJ0EHolPL4BXN3qYm0CQl348/Ub584FvI7/bN8kiXeCYfNRYyza6VhDl3ta2kaywJ0jR TTh4hdyiRTL4PPn5xcWsaeTIfnVLsso91+F4dbXs1FQTN+hOWRdd7F6BbH+OwrLxOGo2j1Tg1s4ew irM/DbEji/iVjnpMcYxw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xP0O4-00000009dHm-1drA; Thu, 05 Nov 2026 16:32:28 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xP0No-00000009d5L-1rfM for linux-arm-kernel@lists.infradead.org; Thu, 05 Nov 2026 16:32:18 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 3892043646; Thu, 5 Nov 2026 16:32:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 86C1C1F000C1; Thu, 5 Nov 2026 16:32:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793896332; bh=u7ZwqjtzSR0o1QTyifWY7mPwVdBSMzMSz40FvvcurNg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=W+hHuRN0Y5gzd6aWT5/N9Fq9DIQ/crqWKTYS0dP9WisN7+kvm/ozSS/Ty50vTm9j5 KVr4uquyaDcDTL4NF9+4DxmPsHmeWzo5+IQOrPH/k1PvDU8STNaapaShu0YBRGtMIE MOkuSQ4W07rX0usTUfMrKZm+/zRvKEciMW25oWQnkw5lSnl6W3HWtY6qO7vE0RjlS7 68bNosHivjjs3d8kUUryLbpsFLzClC0BPKaxydqoV+AWmfgGl0g7jxA8nkpsP2Jvet rXOIZag/0RJbEzuw95OANkVmXmWPO4+OFqW/+AoZrNxdZ/uraYCeDkvTkRAHnPkhne j5DpNQ4zpWlsg== From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Daniel Lezcano , Marc Zyngier , Marco Crivellari , Mark Rutland , Peter Zijlstra , Phil Auld , Thomas Gleixner , Waiman Long , linux-arm-kernel@lists.infradead.org, "Paul E. McKenney" Subject: [PATCH 24/47] clocksource/drivers/arm_arch_timer: Move CPUHP_AP_ARM_ARCH_TIMER_EVTSTRM_STARTING post stop_machine() Date: Thu, 5 Nov 2026 17:30:22 +0100 Message-ID: <20261105163045.38862-25-frederic@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261105163045.38862-1-frederic@kernel.org> References: <20261105163045.38862-1-frederic@kernel.org> X-Archived-By: 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-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" X-Spam-Status: No, score=-18.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 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 clears the CPU from the evtstrm_available cpumask, which is only ever checked locally for the current CPU. And set/clear from other CPUs are atomic. Therefore this callback is safe to 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 3c561a630962..6f4c609163e5 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_ARM_ARCH_TIMER_STARTING); + enum cpuhp_state target = max((int)st->target, CPUHP_AP_ARM_ARCH_TIMER_EVTSTRM_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_ARM_ARCH_TIMER_STARTING); + WARN_ON(st->state != CPUHP_AP_ARM_ARCH_TIMER_EVTSTRM_STARTING); /* * Invoke the former CPU_DYING callbacks. DYING must not fail! */ -- 2.53.0