Re: -rt kernel just can show 8 perf events?

["Shi, Yang" <yang.shi@linaro.org>]

On 2/4/2016 7:16 AM, Sebastian Andrzej Siewior wrote:
> * Shi, Yang | 2015-12-11 09:57:06 [-0800]:
>
>> On 12/11/2015 9:36 AM, Sebastian Andrzej Siewior wrote:
>>> And 4.1.12 (without -rt13) is not having this kind of problem?
>>
>> No. mainline 4.1.12 works well.
>
> The same thing here. But I get this:
>
>   Performance counter stats for 'tar tJ':
>
>             144,407      cs
>              16,733      page-faults
>              16,732      minor-faults
>                   1      major-faults
>             805,335      iTLB-load-misses                                              (24.83%)
>           6,606,698      dTLB-load-misses                                              (24.63%)
>       3,734,425,072      branches                                                      (37.35%)
>         228,660,856      L1-dcache-prefetches                                          (37.06%)
>           4,564,273      L1-icache-prefetches                                          (49.68%)
>         399,365,890      branch-misses             #   10.69% of all branches          (62.63%)
>          79,278,129      cache-misses                                                  (62.96%)
>      30,825,564,763      cycles                                                        (50.79%)
>
>         8.705696429 seconds time elapsed
>
> once I apply this chunk:

Thanks. I will have a try with the patch soon.

Yang

>
> diff --git a/kernel/events/core.c b/kernel/events/core.c
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -802,6 +802,7 @@ static void __perf_mux_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu)
>   	raw_spin_lock_init(&cpuctx->hrtimer_lock);
>   	hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
>   	timer->function = perf_mux_hrtimer_handler;
> +	timer->irqsafe = 1;
>   }
>
>   static int perf_mux_hrtimer_restart(struct perf_cpu_context *cpuctx)
>
>> Yang
>
> Sebastian
>