From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4525C1851 for ; Mon, 8 Apr 2024 03:27:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712546868; cv=none; b=dndp2hkN6J3BEoZjUC/5ZiPyY5JC5NiSwEgpDNv/dnvDtKCQXPPekrmbHLhipHSUTEh3Upoy6PZWtK9ZDyzjTvM/to1tEQty0sv+3W8qu0BoxHABPjaW5NyTy4bj1v+Cv/wlg7f3MoXUErvJj2BbGdUk2KWyoNr4TLI3Q8qY5UA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712546868; c=relaxed/simple; bh=jPI5SyrsOyNxdrvAEgPm/G9kbPv5nJKkPRPUqjYiE6s=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: Content-Type:MIME-Version; b=TGCkO/eqKDIp2UcrdqAFJ/vMKtjF0vfzr9FmzgpMdn9lJCEuPRfdzNnlpvugOZ4Hdgc43C5lNBJz3CmCD6tDWQcf2UTeaEOfl+W1Ce4bcfcbeX66+dNimAmY1fNyf/hBF3jm5Fp+tczw4kPxarMhZFp3mmox4ypJdBi7hHfj8S8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=U5aeWSeu; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="U5aeWSeu" Received: by smtp.kernel.org (Postfix) with ESMTPS id CB555C433A6 for ; Mon, 8 Apr 2024 03:27:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1712546867; bh=jPI5SyrsOyNxdrvAEgPm/G9kbPv5nJKkPRPUqjYiE6s=; h=From:To:Subject:Date:In-Reply-To:References:From; b=U5aeWSeuyAs1nIaUtG3QbVrgDv8ZVMdNnBLx0r1NaaFENvpG+mB5IeWZ9GLRosy4F wqje53q7cPOPuAlyggdI4npwGdcxSAecEex4rk2ijeqP4anA1MrrwiDSgbFSV4oxa9 NM/nPE/uEI2EAXL/4NLam/INNu46VrabBNFs61N8xQVMf0z6vSzeqFQMJM6OxRlQrT 0Mos572owyglw7lxAN0guEWVfI1aK7EiPMYSs78iIsxf4WOqXRsv61oH4g4ExkuONM dt+iyTee/f87WhBWQc3Vjt42SHpehoutpwFOrFfGKPIsuwIY0JcIUdNllrFzK7LTS5 QDD03eKUAH+Tw== Received: by aws-us-west-2-korg-bugzilla-1.web.codeaurora.org (Postfix, from userid 48) id C5715C4332E; Mon, 8 Apr 2024 03:27:47 +0000 (UTC) From: bugzilla-daemon@kernel.org To: linux-pm@vger.kernel.org Subject: [Bug 217931] amd-pstate lacks crucial features: CPU frequency and boost control Date: Mon, 08 Apr 2024 03:27:47 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed 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: high X-Bugzilla-Who: Perry.Yuan@amd.com X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: linux-pm@vger.kernel.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugzilla.kernel.org/ Auto-Submitted: auto-generated Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 https://bugzilla.kernel.org/show_bug.cgi?id=3D217931 --- Comment #59 from Perry Yuan(AMD) (Perry.Yuan@amd.com) --- (In reply to Artem S. Tashkinov from comment #56) > Here's my report for 6.8.4 and Ryzen 7 7840HS: >=20 > 1. Setting scaling_max_freq works, cool, but you cannot go below 544MHz. = You > can set 400MHz but the CPU will continue to jump to 544MHz, not a big dea= l. >=20 > 2. Setting scaling_min_freq sort of works, the CPU _prefers_ to stay at t= his > specified frequency but occasionally drops to 400MHz. Then, the CPU doesn= 't > totally respect it, i.e. for values below 1.4GHz it stays around 1397MHz. > The relationship is not linear, setting 4GHz results in the CPU preferring > 3766Mhz. Or 2GHz -> 1982MHz. Not a big deal. Unlikely anyone would want to > set the lowest frequency. >=20 > 3. /sys/devices/system/cpu/amd_pstate/cpb_boost is missing altogether: >=20 > # find /sys -iname '*boost*' > [nothing] >=20 > So, my only remaining question is where's boost support? Or it's not > supported for all Zen CPUs? >=20 > Thanks a lot for your work regardless! 1. please try to apply the two patches for your cpb testing.=20 https://lore.kernel.org/lkml/cover.1711335714.git.perry.yuan@amd.com/ https://lore.kernel.org/lkml/Zfqv3ckVU4km+RLr@BLR-5CG11610CF.amd.com/ 2. are you testing under EPP driver mode? the 400MHz is the lowest freq, however it dose not mean the CPU will be keeping at 400MHz, it will wake up= and idle and bump up frequency shortly according to the workload. you need to know, when the Core is idle, kernel will not get the realtime frequency by APERF/MPERF, cpufreq just show the lowest freq as 400MHz. It is not an issu= e.=20 There is one idle frequency defined by power firmware, it is 1.4GHz for some client system, the lowest active frequency is not 400MHz, it is 1.4GHz. so= you have no need to worry the 1.4GHz or 400MHz, it is not a problem. 3. the invalid max frequency value issue is caused by wrong highest perf va= lue defined by pstate driver, I have been working a solution to fix that. with = EPP driver mode, it will not cause any performance problem, just a little uncomfortable to see the wrong value listed.=20=20 Perry. --=20 You may reply to this email to add a comment. You are receiving this mail because: You are the assignee for the bug.=