Re: [PATCH v2] perf vendor events amd: Fix large metrics
From: Ian Rogers
Date: Thu Jul 06 2023 - 09:49:47 EST
On Wed, Jul 5, 2023 at 11:34 PM Sandipan Das <sandipan.das@xxxxxxx> wrote:
>
> There are cases where a metric requires more events than the number of
> available counters. E.g. AMD Zen, Zen 2 and Zen 3 processors have four
> data fabric counters but the "nps1_die_to_dram" metric has eight events.
> By default, the constituent events are placed in a group and since the
> events cannot be scheduled at the same time, the metric is not computed.
> The "all metrics" test also fails because of this.
>
> Use the NO_GROUP_EVENTS constraint for such metrics which anyway expect
> the user to run perf with "--metric-no-group".
>
> E.g.
>
> $ sudo perf test -v 101
>
> Before:
>
> 101: perf all metrics test :
> --- start ---
> test child forked, pid 37131
> Testing branch_misprediction_ratio
> Testing all_remote_links_outbound
> Testing nps1_die_to_dram
> Metric 'nps1_die_to_dram' not printed in:
> Error:
> Invalid event (dram_channel_data_controller_4) in per-thread mode, enable system wide with '-a'.
> Testing macro_ops_dispatched
> Testing all_l2_cache_accesses
> Testing all_l2_cache_hits
> Testing all_l2_cache_misses
> Testing ic_fetch_miss_ratio
> Testing l2_cache_accesses_from_l2_hwpf
> Testing l2_cache_misses_from_l2_hwpf
> Testing op_cache_fetch_miss_ratio
> Testing l3_read_miss_latency
> Testing l1_itlb_misses
> test child finished with -1
> ---- end ----
> perf all metrics test: FAILED!
>
> After:
>
> 101: perf all metrics test :
> --- start ---
> test child forked, pid 43766
> Testing branch_misprediction_ratio
> Testing all_remote_links_outbound
> Testing nps1_die_to_dram
> Testing macro_ops_dispatched
> Testing all_l2_cache_accesses
> Testing all_l2_cache_hits
> Testing all_l2_cache_misses
> Testing ic_fetch_miss_ratio
> Testing l2_cache_accesses_from_l2_hwpf
> Testing l2_cache_misses_from_l2_hwpf
> Testing op_cache_fetch_miss_ratio
> Testing l3_read_miss_latency
> Testing l1_itlb_misses
> test child finished with 0
> ---- end ----
> perf all metrics test: Ok
>
> Reported-by: Ayush Jain <ayush.jain3@xxxxxxx>
> Suggested-by: Ian Rogers <irogers@xxxxxxxxxx>
> Signed-off-by: Sandipan Das <sandipan.das@xxxxxxx>
Acked-by: Ian Rogers <irogers@xxxxxxxxxx>
Will there be a PMU driver fix so that the perf_event_open fails for
the group? That way the weak group would work.
Thanks,
Ian
> ---
>
> Previous versions can be found at:
> v1: https://lore.kernel.org/all/20230614090710.680330-1-sandipan.das@xxxxxxx/
>
> Changes in v2:
> - As suggested by Ian, use the NO_GROUP_EVENTS constraint instead of
> retrying the test scenario with --metric-no-group.
> - Change the commit message accordingly.
>
> tools/perf/pmu-events/arch/x86/amdzen1/recommended.json | 3 ++-
> tools/perf/pmu-events/arch/x86/amdzen2/recommended.json | 3 ++-
> tools/perf/pmu-events/arch/x86/amdzen3/recommended.json | 3 ++-
> 3 files changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/tools/perf/pmu-events/arch/x86/amdzen1/recommended.json b/tools/perf/pmu-events/arch/x86/amdzen1/recommended.json
> index bf5083c1c260..4d28177325a0 100644
> --- a/tools/perf/pmu-events/arch/x86/amdzen1/recommended.json
> +++ b/tools/perf/pmu-events/arch/x86/amdzen1/recommended.json
> @@ -169,8 +169,9 @@
> },
> {
> "MetricName": "nps1_die_to_dram",
> - "BriefDescription": "Approximate: Combined DRAM B/bytes of all channels on a NPS1 node (die) (may need --metric-no-group)",
> + "BriefDescription": "Approximate: Combined DRAM B/bytes of all channels on a NPS1 node (die)",
> "MetricExpr": "dram_channel_data_controller_0 + dram_channel_data_controller_1 + dram_channel_data_controller_2 + dram_channel_data_controller_3 + dram_channel_data_controller_4 + dram_channel_data_controller_5 + dram_channel_data_controller_6 + dram_channel_data_controller_7",
> + "MetricConstraint": "NO_GROUP_EVENTS",
> "MetricGroup": "data_fabric",
> "PerPkg": "1",
> "ScaleUnit": "6.1e-5MiB"
> diff --git a/tools/perf/pmu-events/arch/x86/amdzen2/recommended.json b/tools/perf/pmu-events/arch/x86/amdzen2/recommended.json
> index a71694a043ba..60e19456d4c8 100644
> --- a/tools/perf/pmu-events/arch/x86/amdzen2/recommended.json
> +++ b/tools/perf/pmu-events/arch/x86/amdzen2/recommended.json
> @@ -169,8 +169,9 @@
> },
> {
> "MetricName": "nps1_die_to_dram",
> - "BriefDescription": "Approximate: Combined DRAM B/bytes of all channels on a NPS1 node (die) (may need --metric-no-group)",
> + "BriefDescription": "Approximate: Combined DRAM B/bytes of all channels on a NPS1 node (die)",
> "MetricExpr": "dram_channel_data_controller_0 + dram_channel_data_controller_1 + dram_channel_data_controller_2 + dram_channel_data_controller_3 + dram_channel_data_controller_4 + dram_channel_data_controller_5 + dram_channel_data_controller_6 + dram_channel_data_controller_7",
> + "MetricConstraint": "NO_GROUP_EVENTS",
> "MetricGroup": "data_fabric",
> "PerPkg": "1",
> "ScaleUnit": "6.1e-5MiB"
> diff --git a/tools/perf/pmu-events/arch/x86/amdzen3/recommended.json b/tools/perf/pmu-events/arch/x86/amdzen3/recommended.json
> index 988cf68ae825..3e9e1781812e 100644
> --- a/tools/perf/pmu-events/arch/x86/amdzen3/recommended.json
> +++ b/tools/perf/pmu-events/arch/x86/amdzen3/recommended.json
> @@ -205,10 +205,11 @@
> },
> {
> "MetricName": "nps1_die_to_dram",
> - "BriefDescription": "Approximate: Combined DRAM B/bytes of all channels on a NPS1 node (die) (may need --metric-no-group)",
> + "BriefDescription": "Approximate: Combined DRAM B/bytes of all channels on a NPS1 node (die)",
> "MetricExpr": "dram_channel_data_controller_0 + dram_channel_data_controller_1 + dram_channel_data_controller_2 + dram_channel_data_controller_3 + dram_channel_data_controller_4 + dram_channel_data_controller_5 + dram_channel_data_controller_6 + dram_channel_data_controller_7",
> "MetricGroup": "data_fabric",
> "PerPkg": "1",
> + "MetricConstraint": "NO_GROUP_EVENTS",
> "ScaleUnit": "6.1e-5MiB"
> }
> ]
> --
> 2.34.1
>