From 151a0eb6c8e4398f76453c791d8fd8f8167a7517 Mon Sep 17 00:00:00 2001 From: Hendrik Brueckner Date: Wed, 30 Jan 2013 17:51:56 +0100 Subject: [PATCH] s390/perf: cpum_cf: fallback to software sampling events The CPU-measurement counter facility does not support sampling events and returns -EINVAL in that case. This return code lets the perf tool fail. To fall back to software sampling events, return -ENOENT instead. Signed-off-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/perf_cpum_cf.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/arch/s390/kernel/perf_cpum_cf.c b/arch/s390/kernel/perf_cpum_cf.c index 86ec7447e1f5..390d9ae57bb2 100644 --- a/arch/s390/kernel/perf_cpum_cf.c +++ b/arch/s390/kernel/perf_cpum_cf.c @@ -367,13 +367,6 @@ static int __hw_perf_event_init(struct perf_event *event) if (ev >= PERF_CPUM_CF_MAX_CTR) return -EINVAL; - /* The CPU measurement counter facility does not have any interrupts - * to do sampling. Sampling must be provided by external means, - * for example, by timers. - */ - if (hwc->sample_period) - return -EINVAL; - /* Use the hardware perf event structure to store the counter number * in 'config' member and the counter set to which the counter belongs * in the 'config_base'. The counter set (config_base) is then used @@ -418,6 +411,12 @@ static int cpumf_pmu_event_init(struct perf_event *event) case PERF_TYPE_HARDWARE: case PERF_TYPE_HW_CACHE: case PERF_TYPE_RAW: + /* The CPU measurement counter facility does not have overflow + * interrupts to do sampling. Sampling must be provided by + * external means, for example, by timers. + */ + if (is_sampling_event(event)) + return -ENOENT; err = __hw_perf_event_init(event); break; default: -- 2.20.1