Messages in this thread | | | Date | Thu, 1 Jun 2006 01:07:10 +0200 | From | Ingo Molnar <> | Subject | Re: 2.6.17-rc5-mm1 |
| |
* Andrew Morton <akpm@osdl.org> wrote:
> > >>The x86_65 panic in LTP has changed a bit. Looks more useful now. > > >>Possibly just unrelated new stuff. Possibly we got lucky. > > > > > > What are you doing to make this happen? > > > > runalltests on LTP > > > > We have to get to the bottom of this - there's a shadow over about 500 > patches and we don't know which. > > iirc I tried to reproduce this a couple of weeks back and failed.
Martin, is the box still somewhat operational after such a crash? If yes then we could use my crash-tracer to see the kernel function call history leading up to the crash:
http://redhat.com/~mingo/lockdep-patches/latency-tracing-lockdep.patch
just apply the patch, accept the offered Kconfig defaults and it will be configured to do the trace-crashes thing. Reproduce the crash and save /proc/latency_trace - it contains the execution history leading up to the crash. (on the CPU that crashes) Should work on i386 and x86_64.
the trace is saved upon the first crash or lockdep assert that occurs on the box. (but you'll have lockdep disabled, so it's the crash that matters)
if the box dies after a crash then there's a possibility to print the execution history to the serial console - but that takes around 10-15 minutes even on 115200 baud. If you want/need to do this then edit kernel/latency.c and change "trace_print_at_crash = 0" to "trace_print_at_crash = 1".
(btw., the tracer has another neat feature as well: if a kernel crashes or triple faults (and reboots) early during bootup, then the tracer can be configured to print all function calls to the serial console, via early_printk() - right when the function calls happen. I debugged numerous nasty boot-time bugs via this. To set it, change "print_functions = 0" to "print_functions = 1" in kernel/latency.c.)
Ingo - 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/
| |