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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 4D2FAC43215 for ; Tue, 19 Nov 2019 19:17:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2A85822441 for ; Tue, 19 Nov 2019 19:17:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574191039; bh=csZmOLvxjI2+OJ2t0MngnlUbh5xOq4tBtMIZxavgdq0=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=0pXx37JumrdlNmH6iwjpPIWC0WO6txG9S7Bv4boScluBbGw2QJ0zIqBmr96WKNthj L1i1E4AfO0n55NlHMwzv70y5szaTOnQGk9it9wh6/cZGSduBtYyRjpSoRJ020bAUGI t5Q5pLiM6Avsg3YbFXGqlrciiM1FMTRO2mrOQ5Jg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727468AbfKSTRS (ORCPT ); Tue, 19 Nov 2019 14:17:18 -0500 Received: from mail-oi1-f193.google.com ([209.85.167.193]:38462 "EHLO mail-oi1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727036AbfKSTRS (ORCPT ); Tue, 19 Nov 2019 14:17:18 -0500 Received: by mail-oi1-f193.google.com with SMTP id a14so20050278oid.5; Tue, 19 Nov 2019 11:17:17 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=wNhSIdXIAMhTZZlTq4fvLUCixY9Z52dvDBqLG8iKTeg=; b=RwYmRCTgVEBKrMJlWvkpWxd/5naacajGqd7cDvNQfe10wT0oEdntJWDUuS7cNHwA5Y Pc3sIynZs9P6WuCaA8VkzLAHA2sa1oNFvHf2M5M8D6iut9pi3R9NAI1LvL66zrlIO1qO r+Y1CDonyZnv8kRpjDVwnZPSNnOuK6VTTqSsqR0x8mzjTFqN/cumHEzq7RzmDWKNGrwf N4lh6JXh0fe8oAEZvyTWO/yFE7AJBkGE7eIrAOmFm0fskx5IVuwuRvyGvm3kow5wG0PN u5N99lSFkWWN6wd9CDh+0STVDUYMwf5wB9il+TNbJmCXb9tz6jf5EvzRS7easWy8HQV/ iBKg== X-Gm-Message-State: APjAAAUf/z5oP2KnQc/BzZfo1tozVfdtdkwkr68hjlKZBS15ZLlP/Z4S dFLN0Fz+ikGeTUG9oJzHqiEVqWz89/B0B6BAl7o= X-Google-Smtp-Source: APXvYqwLfxciI4GS3t+oWbXzFREIpD12GUXpB9UJ5E3BLWwvX0dd5QLcJSKaltQnW2ZhblzctccArehQ8GCNyphjH2U= X-Received: by 2002:aca:1101:: with SMTP id 1mr5643630oir.103.1574191036787; Tue, 19 Nov 2019 11:17:16 -0800 (PST) MIME-Version: 1.0 References: <2811202.iOFZ6YHztY@kreacher> <4551555.oysnf1Sd0E@kreacher> <000001d59d61$eb4e6670$c1eb3350$@net> <000401d59ee6$959e3da0$c0dab8e0$@net> In-Reply-To: <000401d59ee6$959e3da0$c0dab8e0$@net> From: "Rafael J. Wysocki" Date: Tue, 19 Nov 2019 20:17:05 +0100 Message-ID: Subject: Re: [RFT][PATCH 1/3] PM: QoS: Introduce frequency QoS To: Doug Smythies Cc: "Rafael J. Wysocki" , Linux PM , Linux ACPI , LKML , Viresh Kumar , Sudeep Holla , Dmitry Osipenko Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 19, 2019 at 3:35 PM Doug Smythies wrote: > > On 2019.11.17 08:13 Doug Smythies wrote: > > On 2019.11.16 23:35 Doug Smythies wrote: > > >> Hi Rafael, > >> > >> Not sure, but I think it is this one that > >> causes complaining when I try to set the > >> intel_pstate driver to passive mode. > >> I started from active mode, powersave governor, > >> no HWP. > >> > >> Kernel: 5.4-rc7 > >> > >> I did not go back and try previous 5.4 RCs. > > After looking at the git tags for this patch, > I tried kernel 5.4-rc2, which was the closest > Kernel I had to before the patch set was added. > It worked fine, as expected. > > >> I did try kernel 5.3-rc8, because I already had > >> it installed, and it worked fine. > >> > >> I use a script (for years), run as sudo: > >> > >> doug@s15:~/temp$ cat set_cpu_passive > >> #! /bin/bash > >> cat /sys/devices/system/cpu/intel_pstate/status > >> echo passive > /sys/devices/system/cpu/intel_pstate/status > >> cat /sys/devices/system/cpu/intel_pstate/status > >> > >> And I get this (very small excerpt): > >> > >> freq_qos_add_request() called for active request > >> WARNING: CPU: 1 PID: 2758 at kernel/power/qos.c:763 freq_qos_add_request+0x4c/0xa0 > >> CPU: 1 PID: 2758 Comm: set_cpu_passive Not tainted 5.4.0-rc7-stock #727 > >> Failed to add freq constraint for CPU0 (-22) > >> > >> freq_qos_add_request() called for active request > >> WARNING: CPU: 1 PID: 2758 at kernel/power/qos.c:763 freq_qos_add_request+0x4c/0xa0 > >> CPU: 1 PID: 2758 Comm: set_cpu_passive Tainted: G W 5.4.0-rc7-stock #727 > >> Failed to add freq constraint for CPU1 (-22) > > Updated summary of previous emails: > This patch or patch set breaks the after boot > ability to change CPU frequency scaling drivers. > > Using a workaround of booting with > "intel_pstate=passive" seems to prevent the errors. > > Changing between the intel_pstate and intel_cpufreq drivers > (i.e. between active and passive modes) > after boot, either way, causes the errors. i.e. > > Failed to add freq constraint for CPU7 (-22) > (2 per CPU per attempt) These messages come from acpi_processor_ppc_init() and acpi_thermal_cpufreq_init(), AFAICS, which are invoked by acpi_processor_notifier() and that is invoked by the blocking_notifier_call_chain() in cpufreq_online() which tirggers for new policies after adding the max freq QoS request to policy->constraints. The requests added by them should be removed by acpi_processor_ppc_exit() and acpi_thermal_cpufreq_exit(), respectively, invoked by the blocking_notifier_call_chain() in cpufreq_policy_free(), but it looks like that doesn't happen. However, I now also see that freq_qos_remove_request() doesn't clear the qos field in req which is should do, so freq_qos_add_request() will complain and fail if the object pointed to by req is passed to it again. I'll send a patch to test for this later today.