From mboxrd@z Thu Jan 1 00:00:00 1970 From: bugzilla-daemon@bugzilla.kernel.org Subject: [Bug 103351] New: Machine check exception on Broadwell quad-core with SpeedStep enabled Date: Sun, 23 Aug 2015 13:45:11 +0000 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from mail.kernel.org ([198.145.29.136]:45189 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752260AbbHWNpO (ORCPT ); Sun, 23 Aug 2015 09:45:14 -0400 Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E956420654 for ; Sun, 23 Aug 2015 13:45:12 +0000 (UTC) Received: from bugzilla2.web.kernel.org (bugzilla2.web.kernel.org [172.20.200.52]) by mail.kernel.org (Postfix) with ESMTP id ECA2220651 for ; Sun, 23 Aug 2015 13:45:11 +0000 (UTC) Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: linux-pm@vger.kernel.org https://bugzilla.kernel.org/show_bug.cgi?id=103351 Bug ID: 103351 Summary: Machine check exception on Broadwell quad-core with SpeedStep enabled Product: Power Management Version: 2.5 Kernel Version: 4.2rc7 Hardware: x86-64 OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: cpufreq Assignee: linux-pm@vger.kernel.org Reporter: kris7topher@gmail.com Regression: No On my MSI GE62 2QE Apache Pro laptop with an Intel Core i7 5700HQ processor, I am having machine check exceptions appearing randomly when SpeedStep is enabled in the BIOS. I can trigger them quite reliable by running M-x package-install in emacs, but they also occur without any specific reason. The bug can be triggered with the 4.2rc7-mainline kernel, as well as the Arch Linux 4.1.6-1 and 3.14.51-1-lts kernels. Booting with intel_pstate=disable does not solve the problem, only disable SpeedStep in the BIOS altogether does (but that also prevents CPU scaling to be done). After booting with mce=3 to ignore the machine check exception, I managed to capture the following error message: CPU 2: Machine Check Exception: 5 Bank: 4 be00000000800400 RIP !INEXACT! 10: {acpi_processor_ffh_cstate_enter+0x92/0xc0} TSC 41979f424e MISC 7fc7ff2e82b9 PROCESSOR 0:40671 TIME 1439935114 SOCKET 0 APIC 4 microcode d After this error, the affected CPU core reports numerous stalls, and the system remains unusable. Unfortunately, the output of mcelog ("Hardware event. This is not a software error.") did not enlighten me. The issue seems to be connected to the stability issue of the Core i7 5775C processor, which was reported by Phoronix along a workaround athttp://www.phoronix.com/scan.php?page=news_item&px=core-i7-5775c-oc-fixed-mode I also tested the system with memtest86, which did not report any errors in 8 passes. Running Windows 10 x64 Education on the machine (and some CPU and memory intensive scientific computing on it) also remains stable without any anomalies. -- You are receiving this mail because: You are the assignee for the bug.