From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 60ADBC6778A for ; Tue, 3 Jul 2018 16:08:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1D3A6208C2 for ; Tue, 3 Jul 2018 16:08:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1D3A6208C2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933656AbeGCQIY (ORCPT ); Tue, 3 Jul 2018 12:08:24 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:44749 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933465AbeGCQIW (ORCPT ); Tue, 3 Jul 2018 12:08:22 -0400 Received: from hsi-kbw-5-158-153-52.hsi19.kabel-badenwuerttemberg.de ([5.158.153.52] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1faNql-0004tI-V4; Tue, 03 Jul 2018 18:08:20 +0200 Date: Tue, 3 Jul 2018 18:08:19 +0200 (CEST) From: Thomas Gleixner To: Sudeep Holla cc: Kevin Hilman , lkml , fweisbec@gmail.com, Arnd Bergmann , Martin Blumenstingl Subject: Re: [PATCH] tick: prefer a lower rating device only if it's CPU local device In-Reply-To: <20180703154459.GA15335@e107155-lin> Message-ID: References: <1525881728-4858-1-git-send-email-sudeep.holla@arm.com> <20180703105357.GC1715@e107155-lin> <20180703154459.GA15335@e107155-lin> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 3 Jul 2018, Sudeep Holla wrote: > On Tue, Jul 03, 2018 at 08:04:37AM -0700, Kevin Hilman wrote: > > / # ls -l /sys/devices/system/clocksource > > total 0 > > drwxr-xr-x 3 root root 0 Jan 1 00:00 clocksource0 > > drwxr-xr-x 2 root root 0 Jan 1 00:00 power > > -rw-r--r-- 1 root root 4096 Jan 1 00:00 uevent > > / # cat /sys/devices/system/clocksource/clocksource0/available_clocksource > > timer jiffies > > Looks good. > > > / # cat /sys/devices/system/clocksource/clocksource0/current_clocksource > > timer > > > > OK, meson6 clocksource is active > > > / # cat /sys/devices/system/clockevents/broadcast/current_device > > meson6_tick > > OK, it can support broadcast > > > / # cat /sys/devices/system/clockevents/clockevent0/current_device > > dummy_timer > > / # cat /sys/devices/system/clockevents/clockevent1/current_device > > dummy_timer > > / # cat /sys/devices/system/clockevents/clockevent2/current_device > > dummy_timer > > But I can't understand why is dummy_timer the active event source and > not meson6_tick. And you say this is working case ? Looks suspicious. Because if it switches to broadcast mode then the meson timer cannot longer be used as per cpu timer. It's broadcasting to all CPUs via the dummy timer. Thanks, tglx