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 D06FFC433F5 for ; Sun, 3 Apr 2022 16:18:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1359372AbiDCQUu (ORCPT ); Sun, 3 Apr 2022 12:20:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34924 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239092AbiDCQUs (ORCPT ); Sun, 3 Apr 2022 12:20:48 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6DD0BAE4D for ; Sun, 3 Apr 2022 09:18:54 -0700 (PDT) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1649002732; h=from:from:reply-to:subject:subject: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=JAewAqVHqiv1/qOhXJTMX0jz7jAm8m6A2sT3Ddeu93k=; b=Ok9Rt31gL3UjwMJW8njQDOCzwZFRBtLee1JQ/nYFYlgSRRtY/HioJeQB9GAqfq4Vk04iRY CfStC85dr6e2/8X5W9CiKjDwUNkGw9KmJ2X5eZ4cLnsvCLQR4CBbWwLfzBNPczhRnD1L3z eqfXnD5+uowTcsrGty0vS7quKY6oUmwv1u8ybm+sc0+EE16O01ovWUObIePhEw1+4Hyleg 9EEbcaLVlF3aGncv/u7LcQgsgQQvxtLju7mtVOrTs9SfwkHLv/paCxQFe1SfjJ6vu9OKw7 zobdNvjin5c8SBttkCd6SGga3ZPm7c7BpTFogv/QH4BfZXVMdfr+zlCCq0CsZg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1649002732; h=from:from:reply-to:subject:subject: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=JAewAqVHqiv1/qOhXJTMX0jz7jAm8m6A2sT3Ddeu93k=; b=TM3K0tDlcg4YJggDatQjquSGYSrF8oJDi8eo0tsEwTxto2IKHUOzzua/lw73d2mPcrY1C1 JS7K7W35z3q+qYBw== To: Johannes Berg , Vincent Whitchurch Cc: linux-um@lists.infradead.org, linux-kernel@vger.kernel.org, Anna-Maria Gleixner , Frederic Weisbecker Subject: Re: UML time-travel warning from __run_timers In-Reply-To: <84f9d627092660c38400b607198c3b83f795be7f.camel@sipsolutions.net> References: <20220330110156.GA9250@axis.com> <84f9d627092660c38400b607198c3b83f795be7f.camel@sipsolutions.net> Date: Sun, 03 Apr 2022 18:18:51 +0200 Message-ID: <877d86m978.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Apr 02 2022 at 16:09, Johannes Berg wrote: > At init, we get > > init_timer_cpu(0) base 0 clk=0xffff8ad0, next_expiry=0x13fff8acf > init_timer_cpu(0) base 1 clk=0xffff8ad0, next_expiry=0x13fff8acf > > which makes sense, jiffies is set up to wrap very quickly after boot. > > The warning triggers when we have jiffies=0x13fff9600, so it's just > after the "next_expiry", so in this code: which does not make sense. If next_expiry is 0x13fff8acf and jiffies advanced to 0x13fff9600 when the warning triggered, then either it missed to expire the timer at 0x13fff8acf or it failed to recalculate next_expiry. Could you enable all [hr]timer tracepoints on the kernel command line, set panic on warn and ftrace_dump_on_oops which should spill out the tracebuffer on the console and provide the output. That should at least give us an hint what's going on. Thanks, tglx