From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E4E592561AF for ; Mon, 1 Sep 2025 12:41:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756730518; cv=none; b=oKVRIcOTJyVzWXsT2rypVPf7ibg8QZXw5LQzXD+9uF6G+6pzw5GduNJVoBw+EfExTtTuaFg91xBdjZ/Bv5a12t7Tr1IYn3sZ7lCcx6OT4J+Ld1OsyLMqRyd0blw7VxnIQ8I0XgGhSNMPOwT7q6WJkfEOQiHRFAnnRjJGzs6KIww= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756730518; c=relaxed/simple; bh=AXkFA71h5OvT9VAHVnto4+vhG+89ot6HZfpXUOoxD04=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=IVFqzo0DdzwlaDrL6XAiOUMoViadnkQYhvho8xvLGUuoRC+x2Mwbnb3ZPkDcIk5K18zC9c6ZJpwKRnmk+4pGNNBRz10JNXFSi8XCWFMlhC5CHbs/pZUFzx5c3iIuf4wSzCYznW2dK+BSgKCBNbRNtBjD9SoK4Ycb8D4ey6UdFgs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LOIymi7k; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="LOIymi7k" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1AC63C4CEF9; Mon, 1 Sep 2025 12:41:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756730517; bh=AXkFA71h5OvT9VAHVnto4+vhG+89ot6HZfpXUOoxD04=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=LOIymi7k5dE+c8pPEkBBwti3R3Oy/Ob+anmMjUjICORoXKcqpIffSJPAQL/BSaFB4 CowsqOrwAKTNfmhhMjiVsBsWrXjrG/89mdLBrKlNWNmONhlXzSbPSIsFZsyWh4NdWI iWPZfhB9Qo9FH2co/a5d/qOhX8/Vd4U6JeD5Vij1KWEA8LxGr3ybbSNPqVyMNz3QCO CGm7lsvyPdgbnCapqOeAZr1+idYU6Wp9JycXZg5shpA9/UWr6y3u3aYEcBYI9kw8JJ sF6ORuC+pg34oTJcbMstwwG8iDgYrB8a5BEJLIh2Ep+SJKmJSvqF3Sj768NKlJ/UWJ FC1vv8013Y39w== Date: Mon, 1 Sep 2025 14:41:54 +0200 From: Frederic Weisbecker To: Gabriele Monaco Cc: linux-kernel@vger.kernel.org, Anna-Maria Behnsen , Thomas Gleixner , Waiman Long Subject: Re: [PATCH v11 8/8] timers: Exclude isolated cpus from timer migration Message-ID: References: <20250808160142.103852-1-gmonaco@redhat.com> <20250808160142.103852-9-gmonaco@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20250808160142.103852-9-gmonaco@redhat.com> Le Fri, Aug 08, 2025 at 06:01:42PM +0200, Gabriele Monaco a écrit : > /* > * NOHZ can only be enabled after clocksource_done_booting(). Don't > * bother trashing the cache in the tree before. > */ > static int __init tmigr_late_init(void) > { > - return cpuhp_setup_state(CPUHP_AP_TMIGR_ONLINE, "tmigr:online", > - tmigr_set_cpu_available, tmigr_clear_cpu_available); > + int cpu, ret; > + > + ret = cpuhp_setup_state(CPUHP_AP_TMIGR_ONLINE, "tmigr:online", > + tmigr_set_cpu_available, tmigr_clear_cpu_available); > + if (ret) > + return ret; > + /* > + * The tick CPU may not be marked as available in the above call, this > + * can occur only at boot as hotplug handlers are not called on the > + * tick CPU. Force it enabled here. > + */ > + for_each_possible_cpu(cpu) { > + if (!tick_nohz_cpu_hotpluggable(cpu)) { > + ret = smp_call_function_single( > + cpu, tmigr_cpu_unisolate_force, NULL, 1); > + break; > + } > + } Why not evaluate tick_nohz_cpu_hotpluggable() from tmigr_clear_cpu_available() instead of this force IPI? But if I understand correctly, this will be handled by cpuset, right? Thanks. -- Frederic Weisbecker SUSE Labs