"perf: interrupt took too long" messages even with perf_cpu_time_max_percent==0

[Markus Trippelsdorf]

Current git kernel sometimes shows:

 perf: interrupt took too long (71 > 52), lowering kernel.perf_event_max_sample_rate to 300
 perf: interrupt took too long (103 > 88), lowering kernel.perf_event_max_sample_rate to 300
 perf: interrupt took too long (130 > 128), lowering kernel.perf_event_max_sample_rate to 300
 perf: interrupt took too long (175 > 162), lowering kernel.perf_event_max_sample_rate to 300
 perf: interrupt took too long (219 > 218), lowering kernel.perf_event_max_sample_rate to 300
...

when running e.g. "perf top" even when  
/proc/sys/kernel/perf_cpu_time_max_percent is set to 0.

-- 
Markus