From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastian Andrzej Siewior Subject: Re: Tracers+cyclictest causing kernel oops Date: Fri, 31 May 2013 11:23:38 +0200 Message-ID: <51A86C1A.2040100@linutronix.de> References: <20130503160546.GF8230@linutronix.de> <519B57A7.1010901@linutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: linux-rt-users To: Tom Cook Return-path: Received: from www.linutronix.de ([62.245.132.108]:36802 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752925Ab3EaJXj (ORCPT ); Fri, 31 May 2013 05:23:39 -0400 In-Reply-To: Sender: linux-rt-users-owner@vger.kernel.org List-ID: On 05/21/2013 05:20 PM, Tom Cook wrote: > No. I've also tried compiling without kgdb and enabling tracers still > causes a crash (see below). > > Again, I'm far from expert here, but as near as I can tell, a fast > interrupt exception handler is causing a data abort exception. Do the > tracers use fast interrupts to wake up? Is there some tracer-related > memory that's getting swapped out? I just tried the same thing on my AM33xx and nothing bad happned here. One thing still: you might want to use "-n" for nanosleep. Could you try [0] to check if you are not using more memory than available? If the OOM-killer kills the program, then it is okay, if the data-abort exception comes or the kernel crashes in a strange way then it is HW. The tracer do not use any special interrupts on purpose. Now that I saw rasperry-pi let me ask this: do you have any non-mainline patches on-top? And if it is the case, could you try to get rid of them? Also you can try the same test without the RT patches? [0] http://download.breakpoint.cc/malloc.c Sebastian