On Tue, Sep 10, 2013 at 07:15:19AM -0700, Stephane Eranian wrote: > The threshold is where to generate the interrupt. It does not mean > where to stop PEBS recording.
It does, since we don't set a reset value. So once a PEBS assist happens, that counter stops until we reprogram it in the PMI. > So it is possible that in HSW, we may > get into a situation where it takes time to get to the handler to stop > the PMU. I don't know how given we use NMI. Well, unless we were > already servicing an NMI at the time. But given that we stop the PMU > almost immediately in the handler, I don't see how that would > possible. The other oddity in HSW is that we clear the NMI on entry > to the handler and not at the end. I never gotten an good explanation > as to why that was necessary. So maybe it is related... Even if the PMI was delayed that counter would never do another entry. So I really don't see how we can have more than nr_counters PEBS entries in the buffer. -- 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/
