From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753189AbeD3KEz (ORCPT ); Mon, 30 Apr 2018 06:04:55 -0400 Received: from merlin.infradead.org ([205.233.59.134]:60122 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753028AbeD3KEt (ORCPT ); Mon, 30 Apr 2018 06:04:49 -0400 Message-Id: <20180430100008.503783478@infradead.org> User-Agent: quilt/0.63-1 Date: Mon, 30 Apr 2018 12:00:08 +0200 From: Peter Zijlstra To: tglx@linutronix.de Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, diego.viola@gmail.com, len.brown@intel.com, rjw@rjwysocki.net, rui.zhang@intel.com Subject: [PATCH v2 0/7] Various tsc/clocksource fixes Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org These patches are the result of the regression Diego reported against commit: aa83c45762a2 ("x86/tsc: Introduce early tsc clocksource") His Core2 triggers mark_tsc_unstable() while we're running with tsc-early, which then results in us failing to unregister the clocksource. Furthermore, since mark_tsc_unstable() only looks at the regular tsc clocksource, we don't even mark tsc_early UNSTABLE or de-rate it, resulting in it actually staying a desirable clocksource. Fixing that is a little more tricky; albeit far less critical after we guarantee to unregister tsc-early. Please consider these for /urgent. I've used both Fixes and stable tags on a bunch of them because the above commit is already in v4.16 and would need stable help. These patches have been tested on both a Core2 and an IVB. On IVB I've both changed intel_idle to always report the TSC unstable and mucked about with the TSC msr from userspace to tickle the watchdog paths. --- Changes since v1 - fix __clocksource_change_rating() locking - removed work->kthread->watchdog hoops - fixed up comment