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 2AA1DC46467 for ; Wed, 11 Jan 2023 21:32:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230477AbjAKVcR (ORCPT ); Wed, 11 Jan 2023 16:32:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46556 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235143AbjAKVcO (ORCPT ); Wed, 11 Jan 2023 16:32:14 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B4954D13B for ; Wed, 11 Jan 2023 13:32:13 -0800 (PST) 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 6D805B81D73 for ; Wed, 11 Jan 2023 21:32:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0D55DC433EF; Wed, 11 Jan 2023 21:32:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673472731; bh=dr6fiRdtfzejt5sfT0dVpS69rQ2Pb5vhRcOde1gXe2M=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=czvSYazh+LQrKU1mGIE/sgjUy9zTNozzhTj1hbunML9xWznhNJyPUTix4Mweqs1zC hZJF1Nil3IgMaDWTzDvP2PZZ6ptd18WBrz57C+o4x5OwVouNBw3ak3WbdcTTjOCto9 6VR35fZjIArTk/bdh0mxqSx/FoVAIt0IZNpDj793/Ao8kclokw2lvhy1Bm9lBdJRFv AIdKfcfds47iqBI4HgSdbPuD7D5I7swsmZLk3u7fe7fzVmk91fpGz+I1MjS36FZUzS nvRYLtpGhIiGRr/8W1MBGUEZfv2g/1pxt9FmhCda0r/0kpyE/ZIOMfGGeTjBUC/Xx5 bNFi4DKVpp2lQ== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id A7CE75C0920; Wed, 11 Jan 2023 13:32:10 -0800 (PST) Date: Wed, 11 Jan 2023 13:32:10 -0800 From: "Paul E. McKenney" To: Thomas Gleixner Cc: linux-kernel@vger.kernel.org, john.stultz@linaro.org, sboyd@kernel.org, corbet@lwn.net, Mark.Rutland@arm.com, maz@kernel.org, kernel-team@meta.com, neeraju@codeaurora.org, ak@linux.intel.com, feng.tang@intel.com, zhengjun.xing@intel.com, Waiman Long , John Stultz Subject: Re: [PATCH clocksource 5/6] clocksource: Suspend the watchdog temporarily when high read latency detected Message-ID: <20230111213210.GA4028633@paulmck-ThinkPad-P17-Gen-1> Reply-To: paulmck@kernel.org References: <20230105010429.GA1773522@paulmck-ThinkPad-P17-Gen-1> <20230105010701.1773895-5-paulmck@kernel.org> <87r0w1ia65.ffs@tglx> <20230111175056.GW4028633@paulmck-ThinkPad-P17-Gen-1> <87wn5sepl5.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87wn5sepl5.ffs@tglx> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 11, 2023 at 10:19:50PM +0100, Thomas Gleixner wrote: > On Wed, Jan 11 2023 at 09:50, Paul E. McKenney wrote: > > On Wed, Jan 11, 2023 at 12:26:58PM +0100, Thomas Gleixner wrote: > > Yes, if a system was 100% busy forever, this patch would suppress these > > checks. But 100% busy forever is not the common case, due to thermal > > throttling and to security updates if nothing else. > > > > With all that said, is there a better way to get the desired effects of > > this patch? > > Sane hardware? I must let Feng talk to his systems, but most of the systems I saw were production systems. A few were engineering samples, from which some insanity might be expected behavior. Clearly, something about the hardware or firmware was insane in order to get this result, but that is what diagnostics are for, even on engineering samples. Thanx, Paul