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| author | Thomas Richter <tmricht@linux.ibm.com> | 2021-04-29 15:04:30 +0200 |
|---|---|---|
| committer | Vasily Gorbik <gor@linux.ibm.com> | 2021-06-07 17:06:58 +0200 |
| commit | 15e5b53ff4c92c8ea79094871f91d077bfc60526 (patch) | |
| tree | 966859fdda5f78bd162a4b8e716975d7bc2bc3f6 /arch/s390/kernel/perf_cpum_cf.c | |
| parent | d552a58d708020963f6973a8b3b690f19ac81c99 (diff) | |
| download | lwn-15e5b53ff4c92c8ea79094871f91d077bfc60526.tar.gz lwn-15e5b53ff4c92c8ea79094871f91d077bfc60526.zip | |
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 <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch/s390/kernel/perf_cpum_cf.c')
| -rw-r--r-- | arch/s390/kernel/perf_cpum_cf.c | 8 |
1 files changed, 1 insertions, 7 deletions
diff --git a/arch/s390/kernel/perf_cpum_cf.c b/arch/s390/kernel/perf_cpum_cf.c index 91ee0f399aae..1b7a0525fbed 100644 --- 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 */ |