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 A8A32C433EF for ; Mon, 1 Nov 2021 10:28:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8DC7661058 for ; Mon, 1 Nov 2021 10:28:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232053AbhKAKap (ORCPT ); Mon, 1 Nov 2021 06:30:45 -0400 Received: from smtp-out1.suse.de ([195.135.220.28]:47394 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231946AbhKAKam (ORCPT ); Mon, 1 Nov 2021 06:30:42 -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-out1.suse.de (Postfix) with ESMTPS id D10CB21941; Mon, 1 Nov 2021 10:28:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1635762488; 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=usVlcm16rD4WtoGbsEUNqTyTpA7Ux47Pw/hhZhArBGY=; b=tFJ5sBD3FBPtAw9MezQg7it8KhjmqH8K5z0bz2dIpVE8R2vGTfN06vUsgs9JfEGQ7FXrzt 8mGqrz26LMEeO4jOoneRA4DgfxtgWq1H+CH67cpshO3AFKMGOIvjGIRLA1DxLB8dceqXy+ LLWuKSNAb+U0rfVwbvY+77iznZnOARM= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1635762488; 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=usVlcm16rD4WtoGbsEUNqTyTpA7Ux47Pw/hhZhArBGY=; b=dAwN2+J3gaHn1fuz1paoHW7kVdJdiP0wnJ4n5Yax8OIZdPBQ7QWvI2+ya5+0uGx8XRnwR9 85aQcPoKfFFDFkAg== 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 C325113AA9; Mon, 1 Nov 2021 10:28:08 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id BlubLzjBf2EsTgAAMHmgww (envelope-from ); Mon, 01 Nov 2021 10:28:08 +0000 Received: by incl.suse.cz (Postfix, from userid 1000) id 56A415956F; Mon, 1 Nov 2021 11:28:03 +0100 (CET) Date: Mon, 1 Nov 2021 11:28:03 +0100 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: <20211101102803.GA16089@incl> References: <20211027164352.GA23273@incl> <20211027213829.GB880162@paulmck-ThinkPad-P17-Gen-1> <20211028162025.GA1068@incl> <20211028184209.GH880162@paulmck-ThinkPad-P17-Gen-1> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211028184209.GH880162@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 Thu, Oct 28, 2021 at 11:42:09AM -0700, Paul E. McKenney wrote: > On Thu, Oct 28, 2021 at 06:20:25PM +0200, Jiri Wiesner wrote: > > 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. > > Very good, and thank you for giving it a go! Thank you for the fix! It resolves several strange results we got in our performance testing. > If it passes the upcoming tests I have done 300 reboots of the testing machine. Again, TSC was stable every time. > may I have your Tested-by? Absolutely: Tested-by: Jiri Wiesner