On Tue, Jan 14, 2014 at 05:07:52PM +0100, Alexander Gordeev wrote: > On Mon, Jan 13, 2014 at 04:50:37PM +0100, Frederic Weisbecker wrote: > > On Sat, Jan 04, 2014 at 07:22:32PM +0100, Alexander Gordeev wrote: > > > Hello, > > > > > > This is version 2 of RFC "perf: IRQ-bound performance events". That is an > > > introduction of IRQ-bound performance events - ones that only count in a > > > context of a hardware interrupt handler. Ingo suggested to extend this > > > functionality to softirq and threaded handlers as well: > > > > Hi Alexander, > > > > I still strongly think we should use toggle events to achieve that: > > https://lkml.org/lkml/2013/9/25/227 > > Hi Frederic, > > The toggle events would not allow counting per-action in hardware interrupt > context. The design I propose provisions any possible combination of actions/ > IRQs.
I think we could define one event per handler by using tracepoint filters. > > I.e. if we had few drivers on IRQn and few drivers on IRQm we could assign > an event to let's say ISR0, ISR2 on IRQn and ISR1 on IRQm. Yeah that should be possible with tracepoints as well. > Moreover, given that hardware context handlers are running with local > interrupts disabled and therefore an IRQ-bound event could be enabled/ > disabled only from a single handler at a time - we just need to allocate > a single hardware counter for any possible combination. Hmm I don't get what you mean here. Why tracepoint defined event don't work in this scenario? > > I think it would be ideal if the two approaches could be converged somehow, > but I just do not know how at the moment. I believe the next step is to > measure the overhead Andi mentioned. That well might be a showstopper for > either or both approaches. > > By contrast with the hardware context, the toggle events seem to able > monitoring softirq in its current form. > > As of the threaded context handlers, I have not come up with the idea how to > make it yet, but it does not seem the toggle events are able eigher. A per task event should do the trick for threaded irqs profiling. Thanks. -- 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/
