Re: [PATCH v2 2/2] perf pmu: Improve CPU core PMU HW event list ordering

[Namhyung Kim <namhyung@kernel.org>]

Hello,

On Wed, Jun 17, 2020 at 6:06 PM John Garry <john.garry@huawei.com> wrote:
>
> For perf list, the CPU core PMU HW event ordering is such that not all
> events may will be listed adjacent - consider this example:
>
> $ tools/perf/perf list
>
> List of pre-defined events (to be used in -e):
>
>   duration_time                                      [Tool event]
>
>   branch-instructions OR cpu/branch-instructions/    [Kernel PMU event]
>   branch-misses OR cpu/branch-misses/                [Kernel PMU event]
>   bus-cycles OR cpu/bus-cycles/                      [Kernel PMU event]
>   cache-misses OR cpu/cache-misses/                  [Kernel PMU event]
>   cache-references OR cpu/cache-references/          [Kernel PMU event]
>   cpu-cycles OR cpu/cpu-cycles/                      [Kernel PMU event]
>   cstate_core/c3-residency/                          [Kernel PMU event]
>   cstate_core/c6-residency/                          [Kernel PMU event]
>   cstate_core/c7-residency/                          [Kernel PMU event]
>   cstate_pkg/c2-residency/                           [Kernel PMU event]
>   cstate_pkg/c3-residency/                           [Kernel PMU event]
>   cstate_pkg/c6-residency/                           [Kernel PMU event]
>   cstate_pkg/c7-residency/                           [Kernel PMU event]
>   cycles-ct OR cpu/cycles-ct/                        [Kernel PMU event]
>   cycles-t OR cpu/cycles-t/                          [Kernel PMU event]
>   el-abort OR cpu/el-abort/                          [Kernel PMU event]
>   el-capacity OR cpu/el-capacity/                    [Kernel PMU event]
>
> Notice in the above example how the cstate_core PMU events are mixed in
> the middle of the CPU core events.
>
> For my arm64 platform, all the uncore events get mixed in, making the list
> very disorganised:
>  page-faults OR faults                              [Software event]
>   task-clock                                         [Software event]
>   duration_time                                      [Tool event]
>   L1-dcache-load-misses                              [Hardware cache event]
>   L1-dcache-loads                                    [Hardware cache event]
>   L1-icache-load-misses                              [Hardware cache event]
>   L1-icache-loads                                    [Hardware cache event]
>   branch-load-misses                                 [Hardware cache event]
>   branch-loads                                       [Hardware cache event]
>   dTLB-load-misses                                   [Hardware cache event]
>   dTLB-loads                                         [Hardware cache event]
>   iTLB-load-misses                                   [Hardware cache event]
>   iTLB-loads                                         [Hardware cache event]
>   br_mis_pred OR armv8_pmuv3_0/br_mis_pred/          [Kernel PMU event]
>   br_mis_pred_retired OR armv8_pmuv3_0/br_mis_pred_retired/ [Kernel PMU event]
>   br_pred OR armv8_pmuv3_0/br_pred/                  [Kernel PMU event]
>   br_retired OR armv8_pmuv3_0/br_retired/            [Kernel PMU event]
>   br_return_retired OR armv8_pmuv3_0/br_return_retired/ [Kernel PMU event]
>   bus_access OR armv8_pmuv3_0/bus_access/            [Kernel PMU event]
>   bus_cycles OR armv8_pmuv3_0/bus_cycles/            [Kernel PMU event]
>   cid_write_retired OR armv8_pmuv3_0/cid_write_retired/ [Kernel PMU event]
>   cpu_cycles OR armv8_pmuv3_0/cpu_cycles/            [Kernel PMU event]
>   dtlb_walk OR armv8_pmuv3_0/dtlb_walk/              [Kernel PMU event]
>   exc_return OR armv8_pmuv3_0/exc_return/            [Kernel PMU event]
>   exc_taken OR armv8_pmuv3_0/exc_taken/              [Kernel PMU event]
>   hisi_sccl1_ddrc0/act_cmd/                          [Kernel PMU event]
>   hisi_sccl1_ddrc0/flux_rcmd/                        [Kernel PMU event]
>   hisi_sccl1_ddrc0/flux_rd/                          [Kernel PMU event]
>   hisi_sccl1_ddrc0/flux_wcmd/                        [Kernel PMU event]
>   hisi_sccl1_ddrc0/flux_wr/                          [Kernel PMU event]
>   hisi_sccl1_ddrc0/pre_cmd/                          [Kernel PMU event]
>   hisi_sccl1_ddrc0/rnk_chg/                          [Kernel PMU event]
>
> ...
>
>   hisi_sccl7_l3c21/wr_hit_cpipe/                     [Kernel PMU event]
>   hisi_sccl7_l3c21/wr_hit_spipe/                     [Kernel PMU event]
>   hisi_sccl7_l3c21/wr_spipe/                         [Kernel PMU event]
>   inst_retired OR armv8_pmuv3_0/inst_retired/        [Kernel PMU event]
>   inst_spec OR armv8_pmuv3_0/inst_spec/              [Kernel PMU event]
>   itlb_walk OR armv8_pmuv3_0/itlb_walk/              [Kernel PMU event]
>   l1d_cache OR armv8_pmuv3_0/l1d_cache/              [Kernel PMU event]
>   l1d_cache_refill OR armv8_pmuv3_0/l1d_cache_refill/ [Kernel PMU event]
>   l1d_cache_wb OR armv8_pmuv3_0/l1d_cache_wb/        [Kernel PMU event]
>   l1d_tlb OR armv8_pmuv3_0/l1d_tlb/                  [Kernel PMU event]
>   l1d_tlb_refill OR armv8_pmuv3_0/l1d_tlb_refill/    [Kernel PMU event]
>
> So the events are list alphabetically. However, CPU core event listing is
> special from commit dc098b35b56f ("perf list: List kernel supplied event
> aliases"), in that the alias and full event is shown (in that order).
> As such, the core events may become sparse.
>
> Improve this by grouping the CPU core events and ensure that they are
> listed first for kernel PMU events. For the first example, above, this
> now looks like:
>
> duration_time                                      [Tool event]
>   branch-instructions OR cpu/branch-instructions/    [Kernel PMU event]
>   branch-misses OR cpu/branch-misses/                [Kernel PMU event]
>   bus-cycles OR cpu/bus-cycles/                      [Kernel PMU event]
>   cache-misses OR cpu/cache-misses/                  [Kernel PMU event]
>   cache-references OR cpu/cache-references/          [Kernel PMU event]
>   cpu-cycles OR cpu/cpu-cycles/                      [Kernel PMU event]
>   cycles-ct OR cpu/cycles-ct/                        [Kernel PMU event]
>   cycles-t OR cpu/cycles-t/                          [Kernel PMU event]
>   el-abort OR cpu/el-abort/                          [Kernel PMU event]
>   el-capacity OR cpu/el-capacity/                    [Kernel PMU event]
>   el-commit OR cpu/el-commit/                        [Kernel PMU event]
>   el-conflict OR cpu/el-conflict/                    [Kernel PMU event]
>   el-start OR cpu/el-start/                          [Kernel PMU event]
>   instructions OR cpu/instructions/                  [Kernel PMU event]
>   mem-loads OR cpu/mem-loads/                        [Kernel PMU event]
>   mem-stores OR cpu/mem-stores/                      [Kernel PMU event]
>   ref-cycles OR cpu/ref-cycles/                      [Kernel PMU event]
>   topdown-fetch-bubbles OR cpu/topdown-fetch-bubbles/ [Kernel PMU event]
>   topdown-recovery-bubbles OR cpu/topdown-recovery-bubbles/ [Kernel PMU event]
>   topdown-slots-issued OR cpu/topdown-slots-issued/  [Kernel PMU event]
>   topdown-slots-retired OR cpu/topdown-slots-retired/ [Kernel PMU event]
>   topdown-total-slots OR cpu/topdown-total-slots/    [Kernel PMU event]
>   tx-abort OR cpu/tx-abort/                          [Kernel PMU event]
>   tx-capacity OR cpu/tx-capacity/                    [Kernel PMU event]
>   tx-commit OR cpu/tx-commit/                        [Kernel PMU event]
>   tx-conflict OR cpu/tx-conflict/                    [Kernel PMU event]
>   tx-start OR cpu/tx-start/                          [Kernel PMU event]
>   cstate_core/c3-residency/                          [Kernel PMU event]
>   cstate_core/c6-residency/                          [Kernel PMU event]
>   cstate_core/c7-residency/                          [Kernel PMU event]
>   cstate_pkg/c2-residency/                           [Kernel PMU event]
>   cstate_pkg/c3-residency/                           [Kernel PMU event]
>   cstate_pkg/c6-residency/                           [Kernel PMU event]
>   cstate_pkg/c7-residency/                           [Kernel PMU event]
>
> Signed-off-by: John Garry <john.garry@huawei.com>

Acked-by: Namhyung Kim <namhyung@kernel.org>

Thanks
Namhyung


> ---
>  tools/perf/util/pmu.c | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> index a375364537cd..faa3e0619740 100644
> --- a/tools/perf/util/pmu.c
> +++ b/tools/perf/util/pmu.c
> @@ -1400,6 +1400,7 @@ struct sevent {
>         char *pmu;
>         char *metric_expr;
>         char *metric_name;
> +       int is_cpu;
>  };
>
>  static int cmp_sevent(const void *a, const void *b)
> @@ -1416,6 +1417,11 @@ static int cmp_sevent(const void *a, const void *b)
>                 if (n)
>                         return n;
>         }
> +
> +       /* Order CPU core events to be first */
> +       if (as->is_cpu != bs->is_cpu)
> +               return bs->is_cpu - as->is_cpu;
> +
>         return strcmp(as->name, bs->name);
>  }
>
> @@ -1507,6 +1513,7 @@ void print_pmu_events(const char *event_glob, bool name_only, bool quiet_flag,
>                         aliases[j].pmu = pmu->name;
>                         aliases[j].metric_expr = alias->metric_expr;
>                         aliases[j].metric_name = alias->metric_name;
> +                       aliases[j].is_cpu = is_cpu;
>                         j++;
>                 }
>                 if (pmu->selectable &&
> --
> 2.26.2
>