On Thu, Feb 20, 2014 at 07:15:38PM +0100, Peter Zijlstra wrote: > On Thu, Feb 20, 2014 at 09:31:19AM -0800, Andi Kleen wrote: > > Peter Zijlstra <pet...@infradead.org> writes: > > > > > > It will; trace_printk() works without -pg, I think you didn't read the > > > instructions very well. > > > > Ok, you enable and disable it again. I won't guess why you do that. > > To grow the trace buffers; it starts with just a few pages per cpu; once > you switch to an actual tracer it allocates a sensible amount. > > You can grow it with another interface; but then I'd have to like > remember what that was and how big the normal buffers are. Simply > toggling between tracers is far easier.
I see. > > > > And there's a very good reason not to apply your patch; you can route > > > the function tracer into perf, guess what happens when perf calls the > > > function tracer again :-) > > > > How? > > I think by using the /debug/tracing/events/ftrace/function event, but > I'm not actually sure, I've never used it nor did I write the code to do > it. Jolsa did all that IIRC. > > All I know is that we had some 'fun' bugs around there sometime back. Ok. I don't think it would be a problem in any case, the ftrace code has recursion protection. -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/
