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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 59B1FC55186 for ; Thu, 23 Apr 2020 09:13:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3A7152166E for ; Thu, 23 Apr 2020 09:13:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587633187; bh=O10T2UR8aTOkEcaLjzdafkBdprz/u0SuzibtzuBzbZw=; h=Date:From:To:cc:Subject:In-Reply-To:References:List-ID:From; b=kaSsrWTvy9x4iiV7bedBnnKFfR8UmgaTLWPn4wFHtPtkR0MUulW5oVSOranpdNH/6 imPfJ2rJIEAkanBsvVUsJbkny0B2ojrSIDpIgmXu2IHvKwYbs8L5k/6DXNTf4sPAIB 2A0I9J4r/d18/VcvnoOJAWeVjuo+Q7rtJu21qLuY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726386AbgDWJNE (ORCPT ); Thu, 23 Apr 2020 05:13:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:38172 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726101AbgDWJNE (ORCPT ); Thu, 23 Apr 2020 05:13:04 -0400 Received: from pobox.suse.cz (unknown [195.250.132.148]) (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 07CCD2075A; Thu, 23 Apr 2020 09:13:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587633183; bh=O10T2UR8aTOkEcaLjzdafkBdprz/u0SuzibtzuBzbZw=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=i/HoOCUIiot0hwOgxIq/Y3x3Y5ojRlx/FYGqOUujYgpQJkvGYdbwzfmgyPOcHvCzh TLiA76lLyVJ7pKuk9LBl4D0l0CBigabtPvIeV7+vdy2KthJ+g6V65YwVEM2PWgSzuB aq8YTpQlSt0utBj0UkYRC5NpyDm8WSL8tdjo/TPw= Date: Thu, 23 Apr 2020 11:12:59 +0200 (CEST) From: Jiri Kosina To: Sebastian Andrzej Siewior cc: Thomas Gleixner , LKML , linux-rt-users , Steven Rostedt , Frederic Weisbecker , Matt Fleming , Daniel Wagner Subject: Re: [PREEMPT_RT] 8250 IRQ lockup when flooding serial console (was Re: [ANNOUNCE] v5.4.28-rt19) In-Reply-To: Message-ID: References: <20200330144712.cwcz5ejal4ankeoi@linutronix.de> User-Agent: Alpine 2.21 (LSU 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-rt-users-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org On Thu, 23 Apr 2020, Jiri Kosina wrote: > > I'm pleased to announce the v5.4.28-rt19 patch set. > > First, I don't believe this is necessarily a regression coming with this > particular version, but this is the first kernel where I tried this and it > crashed. I just tried with 5.6.4-rt3, and I can make it explode exactly the same way: [ 46.523586] 000: irq 4: nobody cared (try booting with the "irqpoll" option) 4187418741874187[ 46.523608] 000: CPU: 0 PID: 1219 Comm: irq/4-ttyS0 Not tainted 5.6.4-rt19+ #10 [ 46.523611] 000: Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c89-rebuilt.suse.com 04/01/2014 [ 46.523613] 000: Call Trace: [ 46.523630] 000: [ 46.523638] 000: dump_stack+0x50/0x6b [ 46.523655] 000: __report_bad_irq+0x2b/0xb0 [ 46.523662] 000: note_interrupt+0x22e/0x280 [ 46.523666] 000: ? io_serial_out+0x11/0x20 [ 46.523671] 000: handle_irq_event_percpu+0x6e/0x90 [ 46.523676] 000: handle_irq_event+0x48/0x90 [ 46.523678] 000: handle_edge_irq+0x95/0x1f0 [ 46.523683] 000: do_IRQ+0x6c/0x120 [ 46.523692] 000: common_interrupt+0xf/0xf [ 46.523700] 000: [ 46.523701] 000: RIP: 0010:io_serial_out+0x11/0x20 [ 46.523706] 000: Code: 8b 57 30 d3 e6 01 f2 ec 0f b6 c0 c3 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 0f b6 8f e1 00 00 00 89 d0 8b 57 30 d3 e6 01 f2 ee 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 0f b6 87 e2 00 00 00 [ 46.523709] 000: RSP: 0018:ffffa4ce80813de8 EFLAGS: 00000202 ORIG_RAX: ffffffffffffffdb [ 46.523710] 000: RAX: 0000000000000031 RBX: ffffffffb57a0de0 RCX: 0000000000000000 [ 46.523716] 000: RDX: 00000000000003f8 RSI: 0000000000000000 RDI: ffffffffb57a0de0 [ 46.523718] 000: RBP: ffffa30bf9320000 R08: ffffffffb4c0b7a0 R09: 0000000000000001 [ 46.523719] 000: R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000010 [ 46.523720] 000: R13: 0000000000000020 R14: 0000000000000001 R15: ffffa30bfa737498 [ 46.523730] 000: ? io_serial_in+0x20/0x20 [ 46.523732] 000: serial8250_tx_chars+0x121/0x310 [ 46.523735] 000: ? migrate_disable+0x33/0x90 [ 46.523739] 000: serial8250_handle_irq.part.26+0xbb/0xc0 [ 46.523745] 000: serial8250_default_handle_irq+0x45/0x50 [ 46.523747] 000: serial8250_interrupt+0x51/0xa0 [ 46.523750] 000: ? irq_finalize_oneshot.part.46+0xd0/0xd0 [ 46.523752] 000: irq_forced_thread_fn+0x2b/0x70 [ 46.523754] 000: irq_thread+0xd8/0x170 [ 46.523757] 000: ? wake_threads_waitq+0x30/0x30 [ 46.523759] 000: ? irq_thread_dtor+0x90/0x90 [ 46.523760] 000: kthread+0x10e/0x130 [ 46.523765] 000: ? kthread_park+0x80/0x80 [ 46.523766] 000: ret_from_fork+0x35/0x40 [ 46.523772] 000: handlers: [ 46.523776] 000: [<00000000cdfd4a1d>] irq_default_primary_handler threaded [<0000000078f3e5cd>] serial8250_interrupt [ 46.523778] 000: Disabling IRQ #4 -- Jiri Kosina SUSE Labs