Messages in this thread | | | Date | Mon, 6 Feb 2012 22:25:48 +0100 | Subject | Re: WARNING: at arch/x86/kernel/cpu/perf_event.c:989 | From | Stephane Eranian <> |
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On Mon, Feb 6, 2012 at 9:58 PM, Peter Zijlstra <a.p.zijlstra@chello.nl> wrote: > On Mon, 2012-02-06 at 21:44 +0100, Stephane Eranian wrote: >> Which is pointing to the Intel specific: >> >> intel_pmu_handle_irq() >> again: >> intel_pmu_ack_status(status); >> if (++loops > 100) { >> WARN_ONCE(1, "perfevents: irq loop stuck!\n"); >> perf_event_print_debug(); >> intel_pmu_reset(); >> goto done; >> } >> >> We are in a constant interrupt loop for a reason I don't yet understand. >> Sure we have two counters going, bu given the callstack, one is being >> stopped. >> >> I know we talked about that a couple of weeks back, but after all, it may >> be that it is not possible to run the frequency adjustment code without >> stopping the entire PMU because of risk of interrupts. But it is not clear >> to me what's causing this at this point. > > There's Errata's on this, see AAK157 (SNB) BD106 (WSM) AAK157 (NHM). > Arg, I had forgotten about those..... I'll check on this further with Intel.
> Ingo and I talked about a 'fix' for that based on the text in the SNB > errata which explains why the reset works. Ingo I was under the > impression you were going to implement that? > >> I suggest we still apply my patch to fix the x86_pmu_start() first, then >> I will submit a second patch to fix that one. Agreed? > > Yes. > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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