Re: [PATCH v2 bpf-next 09/11] libbpf: Add perf event names

[Andrii Nakryiko <andrii.nakryiko@gmail.com>]

On Thu, Jun 8, 2023 at 3:35 AM Yafang Shao <laoar.shao@gmail.com> wrote:
>
> Add libbpf API to get generic perf event name.
>
> Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
> ---

I don't think this belongs in libbpf and shouldn't be exposed as
public API. Please move it into bpftool and make it internal (if
Quentin is fine with this in the first place).


>  tools/lib/bpf/libbpf.c   | 107 +++++++++++++++++++++++++++++++++++++++++++++++
>  tools/lib/bpf/libbpf.h   |  56 +++++++++++++++++++++++++
>  tools/lib/bpf/libbpf.map |   6 +++
>  3 files changed, 169 insertions(+)
>
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index 47632606..27d396f 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -119,6 +119,64 @@
>         [BPF_STRUCT_OPS]                = "struct_ops",
>  };
>
> +static const char * const perf_type_name[] = {
> +       [PERF_TYPE_HARDWARE]            = "hardware",
> +       [PERF_TYPE_SOFTWARE]            = "software",
> +       [PERF_TYPE_TRACEPOINT]          = "tracepoint",
> +       [PERF_TYPE_HW_CACHE]            = "hw_cache",
> +       [PERF_TYPE_RAW]                 = "raw",
> +       [PERF_TYPE_BREAKPOINT]          = "breakpoint",
> +};
> +
> +static const char * const perf_hw_name[] = {
> +       [PERF_COUNT_HW_CPU_CYCLES]              = "cpu_cycles",
> +       [PERF_COUNT_HW_INSTRUCTIONS]            = "instructions",
> +       [PERF_COUNT_HW_CACHE_REFERENCES]        = "cache_references",
> +       [PERF_COUNT_HW_CACHE_MISSES]            = "cache_misses",
> +       [PERF_COUNT_HW_BRANCH_INSTRUCTIONS]     = "branch_instructions",
> +       [PERF_COUNT_HW_BRANCH_MISSES]           = "branch_misses",
> +       [PERF_COUNT_HW_BUS_CYCLES]              = "bus_cycles",
> +       [PERF_COUNT_HW_STALLED_CYCLES_FRONTEND] = "stalled_cycles_frontend",
> +       [PERF_COUNT_HW_STALLED_CYCLES_BACKEND]  = "stalled_cycles_backend",
> +       [PERF_COUNT_HW_REF_CPU_CYCLES]          = "ref_cpu_cycles",
> +};
> +
> +static const char * const perf_hw_cache_name[] = {
> +       [PERF_COUNT_HW_CACHE_L1D]               = "l1d",
> +       [PERF_COUNT_HW_CACHE_L1I]               = "l1i",
> +       [PERF_COUNT_HW_CACHE_LL]                = "ll",
> +       [PERF_COUNT_HW_CACHE_DTLB]              = "dtlb",
> +       [PERF_COUNT_HW_CACHE_ITLB]              = "itlb",
> +       [PERF_COUNT_HW_CACHE_BPU]               = "bpu",
> +       [PERF_COUNT_HW_CACHE_NODE]              = "node",
> +};
> +
> +static const char * const perf_hw_cache_op_name[] = {
> +       [PERF_COUNT_HW_CACHE_OP_READ]           = "read",
> +       [PERF_COUNT_HW_CACHE_OP_WRITE]          = "write",
> +       [PERF_COUNT_HW_CACHE_OP_PREFETCH]       = "prefetch",
> +};
> +
> +static const char * const perf_hw_cache_op_result_name[] = {
> +       [PERF_COUNT_HW_CACHE_RESULT_ACCESS]     = "access",
> +       [PERF_COUNT_HW_CACHE_RESULT_MISS]       = "miss",
> +};
> +
> +static const char * const perf_sw_name[] = {
> +       [PERF_COUNT_SW_CPU_CLOCK]               = "cpu_clock",
> +       [PERF_COUNT_SW_TASK_CLOCK]              = "task_clock",
> +       [PERF_COUNT_SW_PAGE_FAULTS]             = "page_faults",
> +       [PERF_COUNT_SW_CONTEXT_SWITCHES]        = "context_switches",
> +       [PERF_COUNT_SW_CPU_MIGRATIONS]          = "cpu_migrations",
> +       [PERF_COUNT_SW_PAGE_FAULTS_MIN]         = "page_faults_min",
> +       [PERF_COUNT_SW_PAGE_FAULTS_MAJ]         = "page_faults_maj",
> +       [PERF_COUNT_SW_ALIGNMENT_FAULTS]        = "alignment_faults",
> +       [PERF_COUNT_SW_EMULATION_FAULTS]        = "emulation_faults",
> +       [PERF_COUNT_SW_DUMMY]                   = "dummy",
> +       [PERF_COUNT_SW_BPF_OUTPUT]              = "bpf_output",
> +       [PERF_COUNT_SW_CGROUP_SWITCHES]         = "cgroup_switches",
> +};
> +
>  static const char * const link_type_name[] = {
>         [BPF_LINK_TYPE_UNSPEC]                  = "unspec",
>         [BPF_LINK_TYPE_RAW_TRACEPOINT]          = "raw_tracepoint",
> @@ -8953,6 +9011,55 @@ const char *libbpf_bpf_attach_type_str(enum bpf_attach_type t)
>         return attach_type_name[t];
>  }
>
> +const char *libbpf_perf_type_str(enum perf_type_id t)
> +{
> +       if (t < 0 || t >= ARRAY_SIZE(perf_type_name))
> +               return NULL;
> +
> +       return perf_type_name[t];
> +}
> +
> +const char *libbpf_perf_hw_str(enum perf_hw_id t)
> +{
> +       if (t < 0 || t >= ARRAY_SIZE(perf_hw_name))
> +               return NULL;
> +
> +       return perf_hw_name[t];
> +}
> +
> +const char *libbpf_perf_hw_cache_str(enum perf_hw_cache_id t)
> +{
> +       if (t < 0 || t >= ARRAY_SIZE(perf_hw_cache_name))
> +               return NULL;
> +
> +       return perf_hw_cache_name[t];
> +}
> +
> +const char *libbpf_perf_hw_cache_op_str(enum perf_hw_cache_op_id t)
> +{
> +       if (t < 0 || t >= ARRAY_SIZE(perf_hw_cache_op_name))
> +               return NULL;
> +
> +       return perf_hw_cache_op_name[t];
> +}
> +
> +const char *
> +libbpf_perf_hw_cache_op_result_str(enum perf_hw_cache_op_result_id t)
> +{
> +       if (t < 0 || t >= ARRAY_SIZE(perf_hw_cache_op_result_name))
> +               return NULL;
> +
> +       return perf_hw_cache_op_result_name[t];
> +}
> +
> +const char *libbpf_perf_sw_str(enum perf_sw_ids t)
> +{
> +       if (t < 0 || t >= ARRAY_SIZE(perf_sw_name))
> +               return NULL;
> +
> +       return perf_sw_name[t];
> +}
> +
>  const char *libbpf_bpf_link_type_str(enum bpf_link_type t)
>  {
>         if (t < 0 || t >= ARRAY_SIZE(link_type_name))
> diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
> index 754da73..4123e4c 100644
> --- a/tools/lib/bpf/libbpf.h
> +++ b/tools/lib/bpf/libbpf.h
> @@ -16,6 +16,7 @@
>  #include <stdbool.h>
>  #include <sys/types.h>  // for size_t
>  #include <linux/bpf.h>
> +#include <linux/perf_event.h>
>
>  #include "libbpf_common.h"
>  #include "libbpf_legacy.h"
> @@ -61,6 +62,61 @@ enum libbpf_errno {
>  LIBBPF_API const char *libbpf_bpf_attach_type_str(enum bpf_attach_type t);
>
>  /**
> + * @brief **libbpf_perf_type_str()** converts the provided perf type value
> + * into a textual representation.
> + * @param t The perf type.
> + * @return Pointer to a static string identifying the perf type. NULL is
> + * returned for unknown **perf_type_id** values.
> + */
> +LIBBPF_API const char *libbpf_perf_type_str(enum perf_type_id t);
> +
> +/**
> + * @brief **libbpf_perf_hw_str()** converts the provided perf hw id
> + * into a textual representation.
> + * @param t The perf hw id.
> + * @return Pointer to a static string identifying the perf hw id. NULL is
> + * returned for unknown **perf_hw_id** values.
> + */
> +LIBBPF_API const char *libbpf_perf_hw_str(enum perf_hw_id t);
> +
> +/**
> + * @brief **libbpf_perf_hw_cache_str()** converts the provided perf hw cache
> + * id into a textual representation.
> + * @param t The perf hw cache id.
> + * @return Pointer to a static string identifying the perf hw cache id.
> + * NULL is returned for unknown **perf_hw_cache_id** values.
> + */
> +LIBBPF_API const char *libbpf_perf_hw_cache_str(enum perf_hw_cache_id t);
> +
> +/**
> + * @brief **libbpf_perf_hw_cache_op_str()** converts the provided perf hw
> + * cache op id into a textual representation.
> + * @param t The perf hw cache op id.
> + * @return Pointer to a static string identifying the perf hw cache op id.
> + * NULL is returned for unknown **perf_hw_cache_op_id** values.
> + */
> +LIBBPF_API const char *libbpf_perf_hw_cache_op_str(enum perf_hw_cache_op_id t);
> +
> +/**
> + * @brief **libbpf_perf_hw_cache_op_result_str()** converts the provided
> + * perf hw cache op result id into a textual representation.
> + * @param t The perf hw cache op result id.
> + * @return Pointer to a static string identifying the perf hw cache op result
> + * id. NULL is returned for unknown **perf_hw_cache_op_result_id** values.
> + */
> +LIBBPF_API const char *
> +libbpf_perf_hw_cache_op_result_str(enum perf_hw_cache_op_result_id t);
> +
> +/**
> + * @brief **libbpf_perf_sw_str()** converts the provided perf sw id
> + * into a textual representation.
> + * @param t The perf sw id.
> + * @return Pointer to a static string identifying the perf sw id. NULL is
> + * returned for unknown **perf_sw_ids** values.
> + */
> +LIBBPF_API const char *libbpf_perf_sw_str(enum perf_sw_ids t);
> +
> +/**
>   * @brief **libbpf_bpf_link_type_str()** converts the provided link type value
>   * into a textual representation.
>   * @param t The link type.
> diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
> index 7521a2f..6ae0a36 100644
> --- a/tools/lib/bpf/libbpf.map
> +++ b/tools/lib/bpf/libbpf.map
> @@ -395,4 +395,10 @@ LIBBPF_1.2.0 {
>  LIBBPF_1.3.0 {
>         global:
>                 bpf_obj_pin_opts;
> +               libbpf_perf_hw_cache_op_result_str;
> +               libbpf_perf_hw_cache_op_str;
> +               libbpf_perf_hw_cache_str;
> +               libbpf_perf_hw_str;
> +               libbpf_perf_sw_str;
> +               libbpf_perf_type_str;
>  } LIBBPF_1.2.0;
> --
> 1.8.3.1
>