On Fri, 8 Nov 2013 23:36:58 +0100 Frederic Weisbecker <[email protected]> wrote:
> [ 237.623178] ---[ end trace 40cda30d05d0ffa6 ]--- > [ 237.627769] perf samples too long (3397569 > 2500), lowering > kernel.perf_event_max_sample_rate to 50000 > [ 237.637124] INFO: NMI handler (perf_event_nmi_handler) took too long to > run: 444.233 msecs > > 444 msecs is huge. I don't think that's the issue you are looking for. Peter told me there's a timer race with overflows or something (I don't remember the details, Peter can clarify it), that causes the second timestamp to be bogus compared to the first, and this makes the code think that the NMI handler was running much longer that it actually was. -- Steve > > [ 247.186562] perf samples too long (3371028 > 5000), lowering > kernel.perf_event_max_sample_rate to 25000 > [ 257.180241] perf samples too long (3344694 > 10000), lowering > kernel.perf_event_max_sample_rate to 13000 > [ 267.173920] perf samples too long (3318566 > 19230), lowering > kernel.perf_event_max_sample_rate to 7000 > [ 277.167598] perf samples too long (3292642 > 35714), lowering > kernel.perf_event_max_sample_rate to 4000 > [ 287.161277] perf samples too long (3266920 > 62500), lowering > kernel.perf_event_max_sample_rate to 2000 > [ 297.154956] perf samples too long (3241400 > 125000), lowering > kernel.perf_event_max_sample_rate to 1000 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
