Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261946AbVASWS0 (ORCPT ); Wed, 19 Jan 2005 17:18:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261925AbVASWPy (ORCPT ); Wed, 19 Jan 2005 17:15:54 -0500 Received: from e32.co.us.ibm.com ([32.97.110.130]:40632 "EHLO e32.co.us.ibm.com") by vger.kernel.org with ESMTP id S261933AbVASWOY (ORCPT ); Wed, 19 Jan 2005 17:14:24 -0500 Subject: Re: 2.6.10-mm1 hang From: Badari Pulavarty To: linux-os@analogic.com Cc: Andrew Morton , Linux Kernel Mailing List In-Reply-To: References: <1106153215.3577.134.camel@dyn318077bld.beaverton.ibm.com> <20050119133136.7a1c0454.akpm@osdl.org> Content-Type: text/plain Organization: Message-Id: <1106171094.3577.156.camel@dyn318077bld.beaverton.ibm.com> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.2.2 (1.2.2-5) Date: 19 Jan 2005 13:44:54 -0800 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1722 Lines: 50 On Wed, 2005-01-19 at 14:01, linux-os wrote: > On Wed, 19 Jan 2005, Andrew Morton wrote: > > > Badari Pulavarty wrote: > >> > >> I was playing with kexec+kdump and ran into this on 2.6.10-mm1. > >> I have seen similar behaviour on 2.6.10. > >> > >> I am using a 4-way P-III machine. I have a module which tries > >> gets same spinlock twice. When I try to "insmod" this module, > >> my system hangs. All my windows froze, no more new logins, > >> console froze, doesn't respond to sysrq. I wasn't expecting > >> a system hang. Why ? Ideas ? > >> > > > > Maybe all the other CPUs are stuck trying to send an IPI to this one? An > > NMI watchdog trace would tell. > > > >> #include > >> #include > >> #include > >> spinlock_t mylock = SPIN_LOCK_UNLOCKED; > >> static int __init panic_init(void) > >> { > >> spin_lock_irq(&mylock); > >> spin_lock_irq(&mylock); > >> return 1; > >> } > > - > > What would you expect this to do? After the first lock is > obtained, the second MUST fail forever or else the spin-lock > doesn't work. The code, above, just proves that spin-locks > work! > I was expecting that one CPU will spin for the lock, while 3 other CPUs do real useful work (on 4-proc machine). Instead my machine is hung - all my windows froze up, no more "ssh", doesn't respond to sysrq to get traces. Only thing it does is, respond to "ping". Thanks, Badari - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/