On Fri, May 31, 2013 at 10:23 AM, Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> wrote: [snip] > 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. Same result. > 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. Seems to be killed by the OOM-killer - see output below. > 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? By 'non-mainline' do you mean in addition to the kernel.org source, or in addition to the raspberry pi git tree? Yes, to the former, no to the latter. > Also you can try the same test without the RT patches? Quite right - the same oops happens with "Linux raspberrypi 3.6.11+ #4 PREEMPT". I think I'm nearly starting to get my head around what's going on here. The USB driver uses FIQs, which normally isn't a problem because nothing would interrupt the FIQ handler (or if it did, it wouldn't generate a page fault). But cyclictest runs at a higher priority than the USB handler and generates page faults (at least when it is initialising). Eventually it interrupts a USB FIQ handler and the memory manager doesn't know what to do with a page fault in a FIQ handler, so it oopses. Does that sound about right? Tom -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
