s390/cpumf: remove WARN_ON_ONCE in counter start handler

Remove some WARN_ON_ONCE() warnings when a counter is started. Each counter is installed function calls event_sched_in() --> cpumf_pmu_add(..., PERF_EF_START). This is done after the event has been created using perf_pmu_event_init() which verifies the counter is valid. Member hwc->config must be valid at this point. Function cpumf_pmu_start(..., PERF_EF_RELOAD) is called from function cpumf_pmu_add() for counter events. All other invocations of cpumf_pmu_start(..., PERF_EF_RELOAD) are from the performance subsystem for sampling events. Signed-off-by: Thomas Richter <[email protected]> Acked-by: Sumanth Korikkar <[email protected]> Signed-off-by: Vasily Gorbik <[email protected]>
josf · Jun 7, 2021 · 15e5b53 · 15e5b53
1 parent d552a58
commit 15e5b53
Showing 1 changed file with 1 addition and 7 deletions.
diff --git a/arch/s390/kernel/perf_cpum_cf.c b/arch/s390/kernel/perf_cpum_cf.c
@@ -362,15 +362,9 @@ static void cpumf_pmu_start(struct perf_event *event, int flags)
 	struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
 	struct hw_perf_event *hwc = &event->hw;
 
-	if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
+	if (!(hwc->state & PERF_HES_STOPPED))
 		return;
 
-	if (WARN_ON_ONCE(hwc->config == -1))
-		return;
-
-	if (flags & PERF_EF_RELOAD)
-		WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
-
 	hwc->state = 0;
 
 	/* (Re-)enable and activate the counter set */