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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DA31BC433F5 for ; Thu, 28 Oct 2021 16:20:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C2AF160FC4 for ; Thu, 28 Oct 2021 16:20:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230248AbhJ1QW5 (ORCPT ); Thu, 28 Oct 2021 12:22:57 -0400 Received: from smtp-out2.suse.de ([195.135.220.29]:33268 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230242AbhJ1QWy (ORCPT ); Thu, 28 Oct 2021 12:22:54 -0400 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 2C9781FD55; Thu, 28 Oct 2021 16:20:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1635438026; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Vwnbx2mDtAHgOvvrGeNNThr1nWlRsUMHYSvEascbsuU=; b=rG/Y1pioiNpQEKED1jtN6UQ07SPJtZt+KNhxwg4Eo68LZmgtWqB29oxtDVn0L1e9ejAy6V IaywZd2Fgdqtbz/AQFY87yxNzQ/JTzdrj4jEe/FjwJw2f04Nfn2Qm8RmxeYfXoJO7AZWCo WUAdl7DDfkMilcIRMB20UWir4YjZi/Y= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1635438026; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Vwnbx2mDtAHgOvvrGeNNThr1nWlRsUMHYSvEascbsuU=; b=PengEVu6JizYyWkbjbkiVolnuMOQ1hVv7y4KjnG4UOsrTt9zg2O5nsMFnJrvFNYdjRDaTP RdXSDJ1frPD+MKCA== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 1DD8F13A9C; Thu, 28 Oct 2021 16:20:26 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id VrxAB8rNemEbTQAAMHmgww (envelope-from ); Thu, 28 Oct 2021 16:20:26 +0000 Received: by incl.suse.cz (Postfix, from userid 1000) id A6896589BD; Thu, 28 Oct 2021 18:20:25 +0200 (CEST) Date: Thu, 28 Oct 2021 18:20:25 +0200 From: Jiri Wiesner To: "Paul E. McKenney" Cc: Thomas Gleixner , Mel Gorman , LKML , Linux-Net Subject: Re: [RFC PATCH] clocksource: increase watchdog retries Message-ID: <20211028162025.GA1068@incl> References: <20211027164352.GA23273@incl> <20211027213829.GB880162@paulmck-ThinkPad-P17-Gen-1> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211027213829.GB880162@paulmck-ThinkPad-P17-Gen-1> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Oct 27, 2021 at 02:38:29PM -0700, Paul E. McKenney wrote: > I had something like this pending, but people came up with other workloads > that resulted in repeated delays. In those cases, it does not make sense > to ever mark the affected clocksource unstable. This led me to the patch > shown below, which splats after about 100 consecutive long-delay retries, > but which avoids marking the clocksource unstable. This is queued on -rcu. > > Does this work for you? > > commit 9ec2a03bbf4bee3d9fbc02a402dee36efafc5a2d > Author: Paul E. McKenney > Date: Thu May 27 11:03:28 2021 -0700 > > clocksource: Forgive repeated long-latency watchdog clocksource reads Yes, it does. I have done 100 reboots of the testing machine (running 5.15-rc5 with the above patch applied) and TSC was stable every time. I am going to start a longer test of 300 reboots for good measure and report back next week. J.