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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C1BAAC433F5 for ; Wed, 5 Jan 2022 00:17:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235475AbiAEAR1 (ORCPT ); Tue, 4 Jan 2022 19:17:27 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:33700 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234119AbiAEAR0 (ORCPT ); Tue, 4 Jan 2022 19:17:26 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 3221EB81898 for ; Wed, 5 Jan 2022 00:17:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D4F5AC36AE0; Wed, 5 Jan 2022 00:17:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1641341843; bh=55rSL6GRXICHDK3q3Eo/KMoAX3C/mwtkjeahSiSnbeg=; h=Date:From:To:Cc:Subject:Reply-To:From; b=cVTP55TkUgq5ReJ2ahzV5jwCqJYR5qO8/XWtQp3X41LcLtHuSzEvKPOi0fIjX4mZp R6cx47d/gZmjQkJcjlcVQilLaW3AMwk2/kBNIpBe1dBP2OOVKPCE7sxYwlG6f1jcU0 w4nbvFNlZXkrcT47KOJKzHV0trmFr7o9EgQGqBezbJLCoSO4ZfzcXis0CaN8QoCMpS cHnVrRmX8xkFrOwCWeqzXSlX372RLUwg0Wjup0303sB9YeZALV9OExrYgQF4xB8DvU emp8mY1EyB7wO0G0hOjBa5NTuzhg+b0zFXMVLNwAJPecaBJG+677Xz+F/XmBavQEbC bhNhStPbOqxjg== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 98FAA5C0C34; Tue, 4 Jan 2022 16:17:23 -0800 (PST) Date: Tue, 4 Jan 2022 16:17:23 -0800 From: "Paul E. McKenney" To: tglx@linutronix.de Cc: longman@redhat.com, feng.tang@intel.com, linux-kernel@vger.kernel.org Subject: [GIT PULL clocksource] Clocksource watchdog commits for v5.17 Message-ID: <20220105001723.GA536708@paulmck-ThinkPad-P17-Gen-1> Reply-To: paulmck@kernel.org MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Thomas, This pull request contains a pair of changes, both courtesy of Waiman Long: 1. Avoids accidental unstable marking of clocksources by rejecting clocksource measurements where the source of the skew is the delay reading reference clocksource itself. This change avoids many of the current false positives caused by epic cache-thrashing workloads. https://lore.kernel.org/lkml/20211118191439.1000012-2-longman@redhat.com/ 2. Reduces the default clocksource_watchdog() retries to 2, thus offsetting the increased overhead due to #1 above rereading the reference clocksource. https://lore.kernel.org/lkml/20211118191439.1000012-3-longman@redhat.com/ These have been subjected to the kbuild test robot and -next testing, and are available in the Git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git clocksource for you to fetch changes up to 1a5620671a1b6fd9cc08761677d050f1702f910c: clocksource: Reduce the default clocksource_watchdog() retries to 2 (2021-11-30 17:22:29 -0800) ---------------------------------------------------------------- Waiman Long (2): clocksource: Avoid accidental unstable marking of clocksources clocksource: Reduce the default clocksource_watchdog() retries to 2 Documentation/admin-guide/kernel-parameters.txt | 4 +- kernel/time/clocksource.c | 52 ++++++++++++++++++++----- 2 files changed, 44 insertions(+), 12 deletions(-)