On Mon, Dec 16, 2013 at 07:45:27AM -0800, Andi Kleen wrote: > > You're right it's extremely slow. But it can still be relevant for > > debugging, > > at least for apps that don't do too much CPU bound stuffs. > > There are patches from Markus already for gdb to use it (using the old > BTS perf interface). I'm not sure they have been merged into gdb > mainline yet though.
Ok. > > > My hope has always been that we can make a userspace function graph tracer > > out of its dumps. And I think we can, I'm pretty sure that would be a > > useful tool. > > I wrote one, based on the __fentry__, like the kernel: > http://github.com/andikleen/ftracer Sounds like nice stuff, but that implies building with the gcc option I think. > > BTS has no timing information, so you could at best do a function tracer > without timing. Right, now although the function timing was the initial purpose of the function graph tracer, the graph itself proved to be much more useful :) But yeah the timing is nice too when we chase hotspot though probably perf report deprecated it. > > -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/
