Messages in this thread | | | Date | Mon, 23 Jan 2023 13:25:46 +0000 | Subject | Re: [PATCH v2 0/9] jevents/pmu-events improvements | From | John Garry <> |
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On 21/12/2022 22:34, Ian Rogers wrote: > Add an optimization to jevents using the metric code, rewrite metrics > in terms of each other in order to minimize size and improve > readability. For example, on Power8 > other_stall_cpi is rewritten from: > "PM_CMPLU_STALL / PM_RUN_INST_CMPL - PM_CMPLU_STALL_BRU_CRU / PM_RUN_INST_CMPL - PM_CMPLU_STALL_FXU / PM_RUN_INST_CMPL - PM_CMPLU_STALL_VSU / PM_RUN_INST_CMPL - PM_CMPLU_STALL_LSU / PM_RUN_INST_CMPL - PM_CMPLU_STALL_NTCG_FLUSH / PM_RUN_INST_CMPL - PM_CMPLU_STALL_NO_NTF / PM_RUN_INST_CMPL" > to: > "stall_cpi - bru_cru_stall_cpi - fxu_stall_cpi - vsu_stall_cpi - lsu_stall_cpi - ntcg_flush_cpi - no_ntf_stall_cpi" > Which more closely matches the definition on Power9. > > A limitation of the substitutions are that they depend on strict > equality and the shape of the tree. This means that for "a + b + c" > then a substitution of "a + b" will succeed while "b + c" will fail > (the LHS for "+ c" is "a + b" not just "b"). > > Separate out the events and metrics in the pmu-events tables saving > 14.8% in the table size while making it that metrics no longer need to > iterate over all events and vice versa. These changes remove evsel's > direct metric support as the pmu_event no longer has a metric to > populate it. This is a minor issue as the code wasn't working > properly, metrics for this are rare and can still be properly ran > using '-M'. > > Add an ability to just build certain models into the jevents generated > pmu-metrics.c code. This functionality is appropriate for operating > systems like ChromeOS, that aim to minimize binary size and know all > the target CPU models.
From a glance, this does not look like it would work for arm64. As I see in the code, we check the model in the arch folder for the test to see if built. For arm64, as it uses arch/implementator/model folder org, and not just arch/model (like x86)
So on the assumption that it does not work for arm64 (or just any arch which uses arch/implementator/model folder org), it would be nice to have that feature also. Or maybe also support not just specifying model but also implementator.
> > v2. Rebase. Modify the code that skips rewriting a metric with the > same name with itself, to make the name check case insensitive. >
Unfortunately you might need another rebase as this does not apply to acme perf/core (if that is what you want), now for me at:
5670ebf54bd2 (HEAD, origin/tmp.perf/core, origin/perf/core, perf/core) perf cs-etm: Ensure that Coresight timestamps don't go backwards
> Ian Rogers (9): > perf jevents metric: Correct Function equality > perf jevents metric: Add ability to rewrite metrics in terms of others > perf jevents: Rewrite metrics in the same file with each other > perf pmu-events: Separate metric out of pmu_event > perf stat: Remove evsel metric_name/expr > perf jevents: Combine table prefix and suffix writing > perf pmu-events: Introduce pmu_metrics_table > perf jevents: Generate metrics and events as separate tables > perf jevents: Add model list option
Thanks, John
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