Commit 15e5b53f authored by Thomas Richter's avatar Thomas Richter Committed by Vasily Gorbik
Browse files

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: default avatarThomas Richter <tmricht@linux.ibm.com>
Acked-by: default avatarSumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent d552a58d

arch/s390/kernel/perf_cpum_cf.c

+1 −7
Original line number Diff line number Diff line
@@ -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 */