From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752167AbbIQVqN (ORCPT ); Thu, 17 Sep 2015 17:46:13 -0400 Received: from www.linutronix.de ([62.245.132.108]:54853 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751702AbbIQVqM (ORCPT ); Thu, 17 Sep 2015 17:46:12 -0400 Date: Thu, 17 Sep 2015 23:45:37 +0200 (CEST) From: Thomas Gleixner To: Yunhong Jiang cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH] nohz: make the idle_entrytime/idle_exittime correct In-Reply-To: <1442445583-10240-1-git-send-email-yunhong.jiang@linux.intel.com> Message-ID: References: <1442445583-10240-1-git-send-email-yunhong.jiang@linux.intel.com> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 16 Sep 2015, Yunhong Jiang wrote: > Currently the idle_entrytime is updated on idle_entry, idle_exit and > get_cpu_idle/iowait_time_us() with non-NULL parameter. This makes the > idle_entrytime not the real entrytime anymore. The idle_exittiime is > updated when exit tickless state, which can be idle tickless or full > tickless. If something calls one of the functions then the cpu is not idle. It's running code. > Change the idle_entrytime to be updated only when enter idle, the > idle_exittime to be updated only when exit idle. Update > the get_cpu_idle_iowait_time_us() accordingly. And the rationale for this change is? Thanks, tglx