Re: [PATCH] perf stat: Suppress warning when using cpum_cf events on s390

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Thu, Mar 16, 2023 at 08:49:46AM +0100, Thomas Richter escreveu:
> Running command perf stat -vv -e cpu_cycles -C0 -- true
> displays this warning:
> 
>  Attempting to add event pmu 'cpum_cf' with 'cpu_cycles,'
>  that may result in non-fatal errors
> 
> Make the PMU cpum_cf selectable and avoid this warning.
> While at it also fix this warning for PMUs pai_crypto and pai_ext.
> 
> Output before:
 

Thanks, applied.

- Arnaldo

>  #  ./perf stat -vv -e cpu_cycles -C0 -- true
>  Using CPUID IBM,3931,704,A01,3.7,002f
>  Attempting to add event pmu 'cpum_cf' with 'cpu_cycles,'
>    that may result in non-fatal errors
>  After aliases, add event pmu 'cpum_cf' with 'event,'
>    that may result in non-fatal errors
>    cpu_cycles -> cpum_cf/event=0/
>  Control descriptor is not initialized
>  ------------------------------------------------------------
>  perf_event_attr:
>   type                             10
>   size                             128
>   config                           0x1001
>   sample_type                      IDENTIFIER
>   read_format                      TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING
>   disabled                         1
>   inherit                          1
>   exclude_guest                    1
>  ------------------------------------------------------------
>  sys_perf_event_open: pid -1  cpu 0  group_fd -1  flags 0x8 = 3
>  cpu_cycles: 0: 290434 2479172 2479172:
>  cpu_cycles: 290434 2479172 2479172
> 
>  Performance counter stats for 'CPU(s) 0':
> 
>            290,434      cpu_cycles
> 
>        0.002465617 seconds time elapsed
>  #
> 
> Now the warning "Attempting to add event pmu 'cpum_cf' ..."
> does not show up anymore.
> 
> Output after:
>  # ./perf stat -vv -e cpu_cycles -C0 -- true
>  Using CPUID IBM,3931,704,A01,3.7,002f
>  After aliases, add event pmu 'cpum_cf' with 'event,'
>    that may result in non-fatal errors
>    cpu_cycles -> cpum_cf/event=0/
>  Control descriptor is not initialized
>  ....
> 
>  Performance counter stats for 'CPU(s) 0':
> 
>            357,023      cpu_cycles
> 
>        0.002454995 seconds time elapsed
>  #
> 
> Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
> ---
>  tools/perf/arch/s390/util/Build |  1 +
>  tools/perf/arch/s390/util/pmu.c | 23 +++++++++++++++++++++++
>  2 files changed, 24 insertions(+)
>  create mode 100644 tools/perf/arch/s390/util/pmu.c
> 
> diff --git a/tools/perf/arch/s390/util/Build b/tools/perf/arch/s390/util/Build
> index db6884086997..fa66f15a14ec 100644
> --- a/tools/perf/arch/s390/util/Build
> +++ b/tools/perf/arch/s390/util/Build
> @@ -6,5 +6,6 @@ perf-$(CONFIG_DWARF) += dwarf-regs.o
>  perf-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o
>  
>  perf-y += machine.o
> +perf-y += pmu.o
>  
>  perf-$(CONFIG_AUXTRACE) += auxtrace.o
> diff --git a/tools/perf/arch/s390/util/pmu.c b/tools/perf/arch/s390/util/pmu.c
> new file mode 100644
> index 000000000000..11f03f32e3fd
> --- /dev/null
> +++ b/tools/perf/arch/s390/util/pmu.c
> @@ -0,0 +1,23 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +/*
> + * Copyright IBM Corp. 2023
> + * Author(s): Thomas Richter <tmricht@linux.ibm.com>
> + */
> +
> +#include <string.h>
> +
> +#include "../../../util/pmu.h"
> +
> +#define	S390_PMUPAI_CRYPTO	"pai_crypto"
> +#define	S390_PMUPAI_EXT		"pai_ext"
> +#define	S390_PMUCPUM_CF		"cpum_cf"
> +
> +struct perf_event_attr *perf_pmu__get_default_config(struct perf_pmu *pmu)
> +{
> +	if (!strcmp(pmu->name, S390_PMUPAI_CRYPTO) ||
> +	    !strcmp(pmu->name, S390_PMUPAI_EXT) ||
> +	    !strcmp(pmu->name, S390_PMUCPUM_CF))
> +		pmu->selectable = true;
> +	return NULL;
> +}
> -- 
> 2.39.1
> 

-- 

- Arnaldo