From mboxrd@z Thu Jan 1 00:00:00 1970 From: u.kleine-koenig@pengutronix.de (Uwe =?iso-8859-1?Q?Kleine-K=F6nig?=) Date: Thu, 2 Aug 2012 09:15:30 +0200 Subject: How to debug hard lockup issue In-Reply-To: References: Message-ID: <20120802071530.GG10670@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hello, On Thu, Aug 02, 2012 at 11:03:31AM +0800, Lin Ming wrote: > I encountered a hard lockup on a armv5 board with 2.6.32 kernel. > There is no any message output since it is hard lockup. > > I tried watchdog, but watchdog can only reset the board. I still can't > get any info. > > The hard lockup is possibly because kernel blocked/looped with > interrupts disabled. > > Is there any non-maskable interrupt I can use to dump the kernel stack? > Or any other hint? Try enabling various debug options. The following come to (my) mind: CONFIG_DETECT_HUNG_TASK CONFIG_PROVE_LOCKING CONFIG_DEBUG_ATOMIC_SLEEP CONFIG_MAGIC_SYSRQ Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-K?nig | Industrial Linux Solutions | http://www.pengutronix.de/ |