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 X-Spam-Level: X-Spam-Status: No, score=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AAD3AC54FCB for ; Mon, 27 Apr 2020 15:54:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 79583206E9 for ; Mon, 27 Apr 2020 15:54:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588002855; bh=GzHcKeJNUKqZMJXI9hV1XJzO/w60O4aCtaOhcc1X/gM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=BiLXqMMbtZqoRh66ZA/JlVNzFC5w+xHNLg/q17AQ5/OqjK3jVBlb9mIQZNORzwdcz sIxXJ9rFwA01JGZrRozU6PJ+C3zzbpP0hLmRDb87lpusg5IDWQLKUSSmsqIbiYFiao KD3Rh9xCfSRrPkUYEpdAlhx7mZF2RGe3tsj7C9Fs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728454AbgD0PyO (ORCPT ); Mon, 27 Apr 2020 11:54:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:32992 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728119AbgD0PyO (ORCPT ); Mon, 27 Apr 2020 11:54:14 -0400 Received: from localhost (unknown [213.57.247.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2CE59206D4; Mon, 27 Apr 2020 15:54:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588002853; bh=GzHcKeJNUKqZMJXI9hV1XJzO/w60O4aCtaOhcc1X/gM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Sc7760sgl9cV7RR6+Ul5gW9Hjs90ASi5+HcKQLCuM/ZlC2UwaeQPAdnBHYvpSUc54 +Ey6GhAXdE4o1N/IcCH544yKfvEMPlXM7iWlqt5Q/rQQWjeHR5jDwnADMgMiXWqBrZ ZqaEJJQ6WdcCMuq5Hz4GK+j8+KWcTiGv4bHlEmNw= Date: Mon, 27 Apr 2020 18:54:10 +0300 From: Leon Romanovsky To: Thomas Gleixner Cc: Ingo Molnar , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , x86 , Suresh Siddha , linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86/apic: Fix circular locking dependency between console and hrtimer locks Message-ID: <20200427155410.GG134660@unreal> References: <20200407170925.1775019-1-leon@kernel.org> <20200414054836.GA956407@unreal> <20200414062454.GA84326@gmail.com> <87tv15qj5u.fsf@nanos.tec.linutronix.de> <20200427113218.GB134660@unreal> <87h7x5qe3v.fsf@nanos.tec.linutronix.de> <20200427134130.GE134660@unreal> <87y2qhoshi.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87y2qhoshi.fsf@nanos.tec.linutronix.de> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 27, 2020 at 05:31:21PM +0200, Thomas Gleixner wrote: > Leon Romanovsky writes: > > OK, I consulted with verification people and back then the trigger was: > > Reproduce when run "echo 1 > /sys/kernel/debug/clear_warn_once" after > > reboot > > That explains it. > > > [ 0.937310] Freeing SMP alternatives memory: 32K > > [ 0.940471] TSC deadline timer enabled > > So here is the first one which sets 'once'. Of course if you clear 'once' > afterwards then this triggers because the context is completely > different. > > So the right thing to do is to move this out of __setup_APIC_LVTT() and > be done with it. Thanks a lot.