From be857b7f77d130dbbd47c91fc35198b040f35865 Mon Sep 17 00:00:00 2001 From: Thomas Richter Date: Fri, 10 Jun 2022 15:19:00 +0200 Subject: s390/cpumf: Handle events cycles and instructions identical Events CPU_CYCLES and INSTRUCTIONS can be submitted with two different perf_event attribute::type values: - PERF_TYPE_HARDWARE: when invoked via perf tool predefined events name cycles or cpu-cycles or instructions. - pmu->type: when invoked via perf tool event name cpu_cf/CPU_CYLCES/ or cpu_cf/INSTRUCTIONS/. This invocation also selects the PMU to which the event belongs. Handle both type of invocations identical for events CPU_CYLCES and INSTRUCTIONS. They address the same hardware. The result is different when event modifier exclude_kernel is also set. Invocation with event modifier for user space event counting fails. Output before: # perf stat -e cpum_cf/cpu_cycles/u -- true Performance counter stats for 'true': cpum_cf/cpu_cycles/u 0.000761033 seconds time elapsed 0.000076000 seconds user 0.000725000 seconds sys # Output after: # perf stat -e cpum_cf/cpu_cycles/u -- true Performance counter stats for 'true': 349,613 cpum_cf/cpu_cycles/u 0.000844143 seconds time elapsed 0.000079000 seconds user 0.000800000 seconds sys # Fixes: 6a82e23f45fe ("s390/cpumf: Adjust registration of s390 PMU device drivers") Signed-off-by: Thomas Richter Acked-by: Sumanth Korikkar [agordeev@linux.ibm.com corrected commit ID of Fixes commit] Signed-off-by: Alexander Gordeev --- arch/s390/kernel/perf_cpum_cf.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) (limited to 'arch/s390/kernel') diff --git a/arch/s390/kernel/perf_cpum_cf.c b/arch/s390/kernel/perf_cpum_cf.c index 483ab5e10164..f7dd3c849e68 100644 --- a/arch/s390/kernel/perf_cpum_cf.c +++ b/arch/s390/kernel/perf_cpum_cf.c @@ -516,6 +516,26 @@ static int __hw_perf_event_init(struct perf_event *event, unsigned int type) return err; } +/* Events CPU_CYLCES and INSTRUCTIONS can be submitted with two different + * attribute::type values: + * - PERF_TYPE_HARDWARE: + * - pmu->type: + * Handle both type of invocations identical. They address the same hardware. + * The result is different when event modifiers exclude_kernel and/or + * exclude_user are also set. + */ +static int cpumf_pmu_event_type(struct perf_event *event) +{ + u64 ev = event->attr.config; + + if (cpumf_generic_events_basic[PERF_COUNT_HW_CPU_CYCLES] == ev || + cpumf_generic_events_basic[PERF_COUNT_HW_INSTRUCTIONS] == ev || + cpumf_generic_events_user[PERF_COUNT_HW_CPU_CYCLES] == ev || + cpumf_generic_events_user[PERF_COUNT_HW_INSTRUCTIONS] == ev) + return PERF_TYPE_HARDWARE; + return PERF_TYPE_RAW; +} + static int cpumf_pmu_event_init(struct perf_event *event) { unsigned int type = event->attr.type; @@ -525,7 +545,7 @@ static int cpumf_pmu_event_init(struct perf_event *event) err = __hw_perf_event_init(event, type); else if (event->pmu->type == type) /* Registered as unknown PMU */ - err = __hw_perf_event_init(event, PERF_TYPE_RAW); + err = __hw_perf_event_init(event, cpumf_pmu_event_type(event)); else return -ENOENT; -- cgit v1.2.3