perf/x86: Fix non-sampling (counting) events on certain x86 platforms

Perf doesn't work at perf stat for hardware events on certain x86 platforms:

 $perf stat -- sleep 1
 Performance counter stats for 'sleep 1':
             16.44 msec task-clock                       #    0.016 CPUs utilized
                 2      context-switches                 #  121.691 /sec
                 0      cpu-migrations                   #    0.000 /sec
                54      page-faults                      #    3.286 K/sec
   <not supported>	cycles
   <not supported>	instructions
   <not supported>	branches
   <not supported>	branch-misses

The reason is that the check in x86_pmu_hw_config() for sampling events is
unexpectedly applied to counting events as well.

It should only impact x86 platforms with limit_period used for non-PEBS
events. For Intel platforms, it should only impact some older platforms,
e.g., HSW, BDW and NHM.

Fixes: 88ec7ee ("perf/x86: Fix low freqency setting issue")
Signed-off-by: Luo Gengkun <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Reviewed-by: Kan Liang <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Ravi Bangoria <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: Luo Gengkun

arch/x86/events/core.c

@@ -629,7 +629,7 @@ int x86_pmu_hw_config(struct perf_event *event)
 	if (event->attr.type == event->pmu->type)
 		event->hw.config |= x86_pmu_get_event_config(event);
 
-	if (!event->attr.freq && x86_pmu.limit_period) {
+	if (is_sampling_event(event) && !event->attr.freq && x86_pmu.limit_period) {
 		s64 left = event->attr.sample_period;
 		x86_pmu.limit_period(event, &left);
 		if (left > event->attr.sample_period)