From mboxrd@z Thu Jan 1 00:00:00 1970 From: bugzilla-daemon@bugzilla.kernel.org Subject: [Bug 197009] /proc/cpuinfo does not update frequency Date: Mon, 20 Nov 2017 14:36:25 +0000 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Return-path: Received: from mail.wl.linuxfoundation.org ([198.145.29.98]:49334 "EHLO mail.wl.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751124AbdKTOg0 (ORCPT ); Mon, 20 Nov 2017 09:36:26 -0500 Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 792A62933B for ; Mon, 20 Nov 2017 14:36:26 +0000 (UTC) In-Reply-To: Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: linux-pm@kernel.org https://bugzilla.kernel.org/show_bug.cgi?id=197009 --- Comment #10 from Hal (haleakalas@yahoo.com) --- Hi Rob. Thanks for your message. I opened the ticket https://bugzilla.kernel.org/show_bug.cgi?id=197017 which was marked as a DUPLICATE of this ticket and closed. That's why I came here to comment and ask my question. I don't want to waste anyone's time and post in the wrong place, but in my experience the /proc/cpuinfo has ramifications beyond just the frequency meter showing the top speed CPU as opposed to the actual real time CPU speed, at least in XFCE according to my experience. Here is why? 1) Starting with 4.13.0 and with every subsequent version of the kernel (including 4.14.0), when used on Linux Mint 18.2 64bit with XFCE, it causes the "CPU Frequency Monitor" to show the top speed of the CPU, not the actual, instantaneous frequency (in average mode). Note that with any prior version, that is not the case and it works as it should. 2) Now, after I posted my bug report, I was let to understand that this was because the XFCE panel plugin read the information from the wrong location, aka "/proc/cpuinfo" rather than "/sys/devices/system/cpu/cpufreq/policy*/scaling_cur_freq". Then my bug report was marked as duplicate of this one and closed. 3) Fetching the CPU info in the wrong place might be only a "cosmetic" issue if it is not being used for anything other than just showing info on the screen. But it seems to be used for more than that. It somehow has a direct impact on "intel_pstate" driver which gets disturbed and results in far greater power consumption. When I observed that, I switched to "acpi_cpufreq" driver and the power consumption got lower but not to the minimum as it was the case with "intel_pstate" when running with an older kernel. I don't know where "acpi_cpufreq" is getting its CPU speed cue but somehow it behaves better than "intel_pstate" on this affected series of kernels. 4) The only exception to this occurrence is with kernel version 4.13.12-041312-generic #201711080535, which I currently use, and which makes my machine behave EXACTLY as it did with older kernel versions. So, for me it WAS a solution. 5) But the fix in 4.13.12 was reversed because apparently it caused to much CPU IPI, etc. I can understand that a different fix is necessary. But I question the wisdom of closing this ticket, unless there is another one that I haven't been able to find yet. As to the "cosmetic" vs "functional" aspect of the issue, it worries me even more because it sounds like I am the only one out there observing power consumption issues. Again to reiterate, on my 6 month old Intel Pentium G4560 desktop I see this issue, on my HP high end laptop with Intel i7-4710HQ, same behavior, and on a low end unbranded laptop with Intel Celeron N3450 same tune! (All three systems running Linux Mint 18.2 XFCE 64 bit in various state of update) I understand this is not a discussion forum and only bug reports should be made with useful information for the developers, and that's what I was trying to do. -- You are receiving this mail because: You are the assignee for the bug.