On Fri, Nov 15, 2013 at 12:56:29PM +0100, Ingo Molnar wrote: > So, here's the current status quo, there's 4 basic types of profiling > that 99% of the people are using, in order of popularity: > > perf record <cmd> > perf record -a sleep N > perf record -p <PID> > perf record -t <TID> > > The first two (which I'd guess comprise about 95% of real-world usage) > have inheritance enabled. > > The last two (-p/-t) have inheritance disabled by default.
Yes, and I would expect it to be disabled for the TID option as you explicitly select a single threads. For the process wide thing it would make sense to enable inheritance by default though. So the big trade-off is that for single threaded processes which do not fork you now have a single buffer, whereas with the inheritance option you'll end up with nr_cpus buffers by default. I suppose for most normal people that's not really an issue; and I suppose all people with silly large machines already pay extra attention -- but at least make it explicit and very clear that this is so. -- 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/