Messages in this thread | | | Date | Tue, 7 Feb 2012 11:31:24 +0100 | Subject | Re: [PATCH] perf: fix assertion failure in x86_pmu_start() | From | Stephane Eranian <> |
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On Tue, Feb 7, 2012 at 11:25 AM, Eric Dumazet <eric.dumazet@gmail.com> wrote: > Le mardi 07 février 2012 à 09:41 +0100, Ingo Molnar a écrit : > >> Were these messages introduced by: >> >> e050e3f0a71b: perf: Fix broken interrupt rate throttling >> >> as well? >> >> In any case I'm holding off on applying the patch before this is >> resolved. > > Reverting e050e3f0a71b solves all my problems, no more warnings. > > $ perf record -a -g hackbench 10 thread 4000 > Running with 10*40 (== 400) tasks. > Time: 13.181 > [ perf record: Woken up 59 times to write data ] > [ perf record: Captured and wrote 16.874 MB perf.data (~737228 samples) > ] > > $ perf record -a -g hackbench 10 thread 4000 > Running with 10*40 (== 400) tasks. > Time: 13.124 > [ perf record: Woken up 61 times to write data ] > [ perf record: Captured and wrote 16.533 MB perf.data (~722349 samples) > ] > What system is this running on? The problem is that without e050e3f0a71b interrupt throttling does not work.
I think the key difference is that without the patch, frequency adjustment happens with the PMU completely stopped whereas with my patch it does not. I suspect this may be the issue. I can rework the patch to disable the PMU completely while retaining the same workflow. -- 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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