From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752863AbeDOTMV (ORCPT ); Sun, 15 Apr 2018 15:12:21 -0400 Received: from outbound.smtp.vt.edu ([198.82.183.121]:60098 "EHLO omr2.cc.vt.edu" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752639AbeDOTMU (ORCPT ); Sun, 15 Apr 2018 15:12:20 -0400 X-Google-Smtp-Source: AIpwx4/RSIrvWnsllFGHyAc9WAgAwGCGJIBpa5dtCPqqdLCWKK6c5WPhvukcKqZa7VPZ9RDaWCisAQ== From: valdis.kletnieks@vt.edu X-Google-Original-From: Valdis.Kletnieks@vt.edu X-Mailer: exmh version 2.8.0 04/21/2017 with nmh-1.7+dev To: Ivid Suvarna Cc: Kernel development list , kernelnewbies@kernelnewbies.org Subject: Re: Softlockup and Hardlockup sample test module In-Reply-To: References: Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1523819531_4636P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Sun, 15 Apr 2018 15:12:11 -0400 Message-ID: <90446.1523819531@turing-police.cc.vt.edu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --==_Exmh_1523819531_4636P Content-Type: text/plain; charset=us-ascii On Sun, 15 Apr 2018 13:17:27 +0530, Ivid Suvarna said: > I had tried with the module where I put a busy loop inside spinlock > but was not able to cause any lockups. Maybe this is because of SMP > which schedule the job to other CPU. "How do I make a task to run on > single CPU only?" So you get a kernel thread that's taken a lock and will busy-loop and not free it. What sort of lockup do you expect will be detected from this? Would the results be any different if you didn't take a lock before busy-looping? For bonus points - what additional things have to happen before a livelock happens? And before a deadlock happens? --==_Exmh_1523819531_4636P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Comment: Exmh version 2.8.0 04/21/2017 iQEVAwUBWtOkC40DS38y7CIcAQJoTwgAksmWck+WZzNBo9TYKvlHhGOSRskb1mBz 2m+oFqhBVfgJ6w0/+QUWmCp/pW66EoLjelPa6PhIA09pK/Q8twV6EnTRTqfxzuOe WZrhBoxSavfp8cIrBw2PLX91enzENjHbwc9wukaLk0eVBO24oEtX2/sQQHUaus97 u/QNUEFQSCFR6qiMTcTUZ6dS+uwwL6QC8UoQi38VHsoSM/nQhrw7cFr4YzNizrAh Kyg8O4E7t9GPwAW2Xa0IUpk5cLsKziQe0qaAPmkpomT7FAPfuUtTEO+KcPyyr64F EQFQAjZ28z7SpqffOMRFEbYHbODF+zZ5zL16Lr8XduIQlJ3xMXaTRQ== =7fja -----END PGP SIGNATURE----- --==_Exmh_1523819531_4636P--