From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753390AbdKND37 (ORCPT ); Mon, 13 Nov 2017 22:29:59 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:19052 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753160AbdKND36 (ORCPT ); Mon, 13 Nov 2017 22:29:58 -0500 Reply-To: zhenzhong.duan@oracle.com Subject: Re: [PATCH] tick/broadcast: Remove redundant code in tick_check_new_device() To: Thomas Gleixner Cc: mingo@kernel.org, fweisbec@gmail.com, Srinivas REDDY Eeda , Joe Jin , linux-kernel@vger.kernel.org References: <35b094f6-70e0-49f2-803a-3333d7ee2524@default> From: Zhenzhong Duan Organization: Oracle Message-ID: <374b90a7-1a7a-5775-73d5-e204bfc69a65@oracle.com> Date: Tue, 14 Nov 2017 11:29:26 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=gbk; format=flowed Content-Transfer-Encoding: 7bit X-Source-IP: userv0022.oracle.com [156.151.31.74] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2017/11/14 0:54, Thomas Gleixner wrote: > On Wed, 8 Nov 2017, Zhenzhong Duan wrote: > >> There is no way a timer used as broadcast clockevent device is also used as >> percpu tick clockevent device currently. > Correct. > >> It's better to put related code in tick_install_broadcast_device(), but I feel >> it's harmless to give it back to the clockevents layer. Pls correct me if I'm >> wrong. > You already established, that it _cannot_ be the broadcast device and the > per cpu device at the same time. So that condition can never be true. What > do you want to put into tick_install_broadcast_device()? This second > paragraph doesn't make sense, unless I'm missing something. I didn't find the reason in long history logs while the comments saying 'If the current device is the broadcast device, do not give it back to the clockevents layer !' If it does, tick_install_broadcast_device() is a proper place. If not, I can resend the patch with fresh description, pls confirm. -- thanks zduan