Peter Zijlstra <pet...@infradead.org> writes: > On Wed, Feb 19, 2014 at 05:34:49PM -0500, Vince Weaver wrote: >> So where would the NMI counter event get disabled? Would it never get >> disabled, just because it's always running and always gets the same fixed >> slot? Why isn't this a problem all the time, not just with corner cases? > > Well it could get another counter assignment I suppose; there's no > guarantee it always ends up in the fixed counter although that's rather > likely. > >> Is somehow n_added getting confused? > > I'd expect worse than a warning if that happened, but who knows. > > You could try with the below; make sure you've got CONFIG_FUNCTION_TRACER=y. > > Then (assuming debugfs is mounted in /debug ; most modern distros have > it at /sys/kernel/debug but they're wrong!): > > # echo 0 > /debug/tracing/tracing_on > # echo function > /debug/tracing/current_tracer > # echo nop > /debug/tracing/current_tracer > # echo 0 > /debug/tracing/trace > # echo 1 > /debug/tracing/tracing_on > > And make it go *BOOM*, then: > > # cat /debug/tracing/trace | bzip2 -9 > ~/trace.bz2
This won't work unless you apply this patch http://lkml.org/lkml/2013/10/20/94 -Andi -- a...@linux.intel.com -- Speaking for myself only -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
