On Fri, Feb 27, 2015 at 03:57:02PM -0800, Andi Kleen wrote: > On Fri, Feb 27, 2015 at 11:05:45PM +0100, Peter Zijlstra wrote: > > On Fri, Feb 27, 2015 at 09:54:34AM -0800, Andi Kleen wrote: > > > > > perf record doesn't show where you're currently blocked. > > > > > > > > Of course it does; look at perf inject -s. > > > > > > Trace points don't support the LBR stack. > > > > Yes, indeed. But would it not make much more sense to squirrel the LBR > > state into sched:sched_switch and teach that inject -s thing to dtrt, > > than to make a proc file that's available on all archs but will only > > work on 1-2 x86 uarchs and only if you're also running the right magic > > perf record at the same time? > > Yes. It would be nice to capture the whole PMU state in trace points. > There are use models for this where it can work better than > sampling. > > But that would be a lot bigger project than this simple file, > which is already quite useful with minimal effort.
Its also the most horrible hack of an interface ever, so no go. -- 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/
