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=-4.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 59DDEC433B4 for ; Mon, 17 May 2021 20:48:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1E01A611B0 for ; Mon, 17 May 2021 20:48:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231238AbhEQUtu (ORCPT ); Mon, 17 May 2021 16:49:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:46436 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229776AbhEQUtt (ORCPT ); Mon, 17 May 2021 16:49:49 -0400 Received: by mail.kernel.org (Postfix) with ESMTPS id 1565B611B0 for ; Mon, 17 May 2021 20:48:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1621284513; bh=d67NDUFWAXkorQCZvFpgOSGP8Mrbs/tYekCm2dGchMo=; h=From:To:Subject:Date:From; b=aavvm7LhskdjvxRFx5md+ttk37ryYkhzkhTWl1CrhEi0msoJf6pWdfCb8snM/sWiZ tzJJC15ViaAjAV9pvdNEoANYit6s/4ssN1s5+8YaUqiR6Uduy9moy8vzmaiamPruuh 9OASPH45vrzpATyFaFHjkUzAqtiy8OQpKVmPw592pNYZTLLtT0GmlJdVG2ya7g6q01 5s/wn3KwStcNHfJxm6AXi6KklSpiqw3mIzTYhTrqa1TAL+DwbnPUqZtDHCReZEK7iu b1+7Nv7zbKQvOd8V85HCZkOyS9PicvMbWhFt6JToNG97UqqekZRUSbd+SAwkBwE6bi ZQb6gfWVHNxLg== From: bugzilla-daemon@bugzilla.kernel.org To: linux-pm@vger.kernel.org Subject: [Bug 213115] New: Unable to set the lowest frequency of AMD CPUs via cpupower - while kernel 5.12.4 (or 5.3.18) is booted with "nosmt" Date: Mon, 17 May 2021 20:48:32 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Power Management X-Bugzilla-Component: cpufreq X-Bugzilla-Version: 2.5 X-Bugzilla-Keywords: X-Bugzilla-Severity: low X-Bugzilla-Who: yan.huang@suse.com X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P1 X-Bugzilla-Assigned-To: linux-pm@vger.kernel.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version cf_kernel_version rep_platform op_sys cf_tree bug_status bug_severity priority component assigned_to reporter cf_regression Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugzilla.kernel.org/ Auto-Submitted: auto-generated MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org https://bugzilla.kernel.org/show_bug.cgi?id=3D213115 Bug ID: 213115 Summary: Unable to set the lowest frequency of AMD CPUs via cpupower - while kernel 5.12.4 (or 5.3.18) is booted with "nosmt" Product: Power Management Version: 2.5 Kernel Version: 5.12.4 Hardware: x86-64 OS: Linux Tree: Mainline Status: NEW Severity: low Priority: P1 Component: cpufreq Assignee: linux-pm@vger.kernel.org Reporter: yan.huang@suse.com Regression: No (Opening this bug as a junior team member of the SUSE Customer Support) A SUSE customer wasn't able to set the lowest possible CPU frequency value = via cpupower on SUSE Linux Enterprise Desktop 15 SP2 (with the kernel 5.3.18) on machines with AMD A12-9720P and AMD Ryzen 5 3550H - while they were booted = with "nosmt". The customer said that this was working on the previous SUSE Linux Enterpri= se Desktop 15 SP1 (with the kernel 4.12.14). Just for this purpose, I purchased a laptop Lenovo IdeaPad 3-15ADA05 with A= MD Ryzen 3 3250U and was able to replicate the issue - with the kernel 5.3.18 = (the default one for SUSE Linux Enterprise Desktop 15 SP2) and the newest stable kernel 5.12.4. AMD Ryzen 3 3250U - https://www.amd.com/en/products/apu/amd-ryzen-3-3250u - 1st gen Zen - 2 cores, 4 threads - base frequency: 2.60 GHz - boost frequency: 3.50 GHz - cpupower frequency-info -- hardware limits: 1.40 GHz - 2.60 GHz -- available frequency steps: 2.60 GHz, 1.70 GHz, 1.40 GHz Each time, I ran this command and expected the CPU core/thread frequencies = to be =3D< 1400 MHz: modprobe cpufreq_userspace && cpupower frequency-set -g userspace && cpupow= er frequency-set -f 1.40GHz && echo 0 > /sys/devices/system/cpu/cpufreq/boost Default kernel 5.3.18 I. without "nosmt" (ok) 1) initially: > localhost:~ # grep MHz /proc/cpuinfo > cpu MHz : 1308.436 > cpu MHz : 1218.734 > cpu MHz : 1301.057 > cpu MHz : 1377.824 2) after running the command: > localhost:~ # grep MHz /proc/cpuinfo > cpu MHz : 1394.225 > cpu MHz : 1391.125 > cpu MHz : 1352.398 > cpu MHz : 1356.574 II. with "nosmt" (fail) 1) initially: > localhost:~ # grep MHz /proc/cpuinfo > cpu MHz : 1434.860 > cpu MHz : 1557.750 2) after running the command: > localhost:~ # grep MHz /proc/cpuinfo > cpu MHz : 2068.443 > cpu MHz : 1921.816 Kernel 4.12.14 - obtained from https://download.opensuse.org/repositories/Kernel:/SLE15-SP1/standard/x86_6= 4/ (no longer available) I. without "nosmt" (ok) 1) initially: > localhost:~ # grep MHz /proc/cpuinfo > cpu MHz : 1700.000 > cpu MHz : 1400.000 > cpu MHz : 1400.000 > cpu MHz : 1400.000 2) after running the command: > localhost:~ # grep MHz /proc/cpuinfo > cpu MHz : 1400.000 > cpu MHz : 1400.000 > cpu MHz : 1400.000 > cpu MHz : 1400.000 II. with "nosmt" (ok) 1) initially: > localhost:~ # grep MHz /proc/cpuinfo > cpu MHz : 1400.000 > cpu MHz : 1400.000 2) after running the command: > localhost:~ # grep MHz /proc/cpuinfo > cpu MHz : 1400.000 > cpu MHz : 1400.000 Kernel 5.12.4 - obtained from https://download.opensuse.org/repositories/Kernel:/stable/standard/x86_64/ I. without "nosmt" (ok) 1) initially: > localhost:~ # grep MHz /proc/cpuinfo > cpu MHz : 1400.000 > cpu MHz : 1400.000 > cpu MHz : 2263.054 > cpu MHz : 1269.757 2) after running the command: > localhost:~ # grep MHz /proc/cpuinfo > cpu MHz : 1400.000 > cpu MHz : 1340.634 > cpu MHz : 1400.000 > cpu MHz : 1400.000 II. with "nosmt" (fail) 1) initially: > localhost:~ # grep MHz /proc/cpuinfo > cpu MHz : 1494.915 > cpu MHz : 2600.000 2) after running the command: > localhost:~ # grep MHz /proc/cpuinfo > cpu MHz : 1731.255 > cpu MHz : 1400.000 I also tested various kernel versions from http://download.opensuse.org/repositories/home:/tiwai:/kernel:/ - it seems = that the issue started in 5.1.x or earlier (I wasn't able to boot every kernel version). I opened a SUSE Bugzilla bug bsc#1175231, but it was decided to not pursue a fix for this corner-case issue at SUSE's level (the solution is to just avo= id "nosmt"). The issue should be replicable even on openSUSE Leap 15.2 with the above mentioned kernels. It is possible that the issue is limited to the 1st generation of AMD Ryzen CPUs (and AMD's pre-Ryzen CPUs). --=20 You may reply to this email to add a comment. You are receiving this mail because: You are the assignee for the bug.=