From mboxrd@z Thu Jan 1 00:00:00 1970 From: daniel.lezcano@linaro.org (Daniel Lezcano) Date: Thu, 15 May 2014 11:05:53 +0200 Subject: RCU stall on panda In-Reply-To: <53747E6D.60500@linaro.org> References: <53675C5F.10509@linaro.org> <20140505180617.GM8754@linux.vnet.ibm.com> <20140512212102.GF5668@atomide.com> <5371BD69.8010600@linaro.org> <20140513153220.GC16837@atomide.com> <53747E6D.60500@linaro.org> Message-ID: <53748371.5030704@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 05/15/2014 10:44 AM, Alex Shi wrote: > On 05/13/2014 11:32 PM, Tony Lindgren wrote: >> * Alex Shi [140512 23:37]: >>> On 05/13/2014 05:21 AM, Tony Lindgren wrote: >>>> * Paul E. McKenney [140505 11:11]: >>>>> On Mon, May 05, 2014 at 05:39:43PM +0800, Alex Shi wrote: >>>>>> I keep seeing the RCU stall problem on panda board from 3.10 kernel to latest upstream kernel >>>>>> and google find some one report it before: https://lkml.org/lkml/2012/9/20/519 >>>>>> >>>>>> Is it the hardware issue or a real software problem? >>>>> >>>>> I cannot distinguish between hardware and software from the trace below, >>>>> but given that you are also seeing a soft lockup, either way you do >>>>> appear to have a real problem as opposed to an RCU CPU stall warning >>>>> false positive. >>>> >>>> Looks like you have CPU_IDLE enabled on panda. Hangs with current linux >>>> next with CPU_IDLE are currently being discussed on the linux-omap list >>>> in thread "omap4-panda-es boot issues with v3.15-rc4" >>>> >>>> I've seen occasional system hangs, and I've also noticed that doing >>>> ctrl-a-f h or ctrl-a-f l for sysrq backtrace can unlock the system >>>> producing similar errors to the below. >>>> >>> >>> Thanks a lot for the info. >>> In fact, the oops keeps in upstream kernel from 3.10 to latest. >> >> Care to test if the revert of commit cb7094 Santosh posted as >> "[PATCH] ARM: OMAP4: Fix the boot regression with CPU_IDLE enabled" >> solves the problem for you? >> > > After enable this patch, system maybe hang in idle. :( Hi Alex, do you mean even with this revert applied, the board hangs in idle ? -- Linaro.org ? Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog