Using CONFIG_FUNCTION_TRACE

From: Darren Hart
Date: Fri Dec 14 2007 - 01:11:35 EST


I was trying to use CONFIG_FUNCTION_TRACE with the example trace-it.c in
linux/scripts. On both 2.6.23.9-rt13 and 2.6.24-rc2-rt1 the system
slower becomes less responsive (measured by typing in ssh and a serial
console) until after a couple minutes it doesn't respond to anything
including sysrq, requiring a power cycle.

The trace-it.c program defaults to 10 seconds of tracing, I even tried
dropping that to 100 us in case it just added so much overhead that 10
seconds of idle turned into minutes. But the 100us sleep hung too.

I tested on a 4 way (2x2) opteron.

I enabled:

CONFIG_EVENT_TRACE
CONFIG_FUNCTION_TRACE

Thanks,

--
Darren Hart
IBM Linux Technology Center
Real-Time Linux Team
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/