From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752641Ab0E3JUM (ORCPT ); Sun, 30 May 2010 05:20:12 -0400 Received: from one.firstfloor.org ([213.235.205.2]:60841 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751754Ab0E3JUK (ORCPT ); Sun, 30 May 2010 05:20:10 -0400 To: Len Brown Cc: Andrew Morton , x86@kernel.org, linux-pm@lists.linux-foundation.org, Linux Kernel Mailing List Subject: Re: [PATCH 8/8] intel_idle: create a native cpuidle driver for select intel processors From: Andi Kleen References: <1274928151-30919-1-git-send-email-lenb@kernel.org> <198450ec1600d9a7f55270dd4d44d6b55bc5b184.1274926772.git.len.brown@intel.com> <20100526204426.fd2be7e0.akpm@linux-foundation.org> Date: Sun, 30 May 2010 11:20:02 +0200 In-Reply-To: (Len Brown's message of "Thu\, 27 May 2010 23\:57\:42 -0400 \(EDT\)") Message-ID: <87zkzhzqyl.fsf@basil.nowhere.org> User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Len Brown writes: >> ... What happens when an additional CPU is brought online? >> It melts? ;) > > With the current driver, processors hot-added after modprobe > will use C1 only, and not use deeper C-states. I agree with Andrew that it will likely not be a lot of effort to restructure the driver to handle cpu hotplug properly, and it's better done from the beginning. -Andi -- ak@linux.intel.com -- Speaking for myself only.