Messages in this thread | | | Date | Fri, 6 Jan 2023 15:59:07 +0000 | Subject | Re: [PATCH v6 1/7] perf vendor events arm64: Add common topdown L1 metrics | From | John Garry <> |
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On 06/01/2023 15:05, Jing Zhang wrote: > The metrics of topdown L1 are from ARM sbsa7.0 platform design doc[0], > D37-38, which are standard. So put them in the common file sbsa.json of > arm64, so that other cores besides n2/v2 can also be reused. > > Slots may be different in each architecture, so added "#slots" literal > to get different constant for each architecture. > > The value of slots comes from the register PMMIR_EL1, which I can read > in /sys/bus/event_source/device/armv8_pmuv3_*/caps/slots. PMMIR_EL1.SLOT > might read as zero if the STALL_SLOT event is not implemented or the PMU > version is lower than ID_AA64DFR0_EL1_PMUVer_V3P4. > > [0] https://urldefense.com/v3/__https://documentation-service.arm.com/static/60250c7395978b529036da86?token=__;!!ACWV5N9M2RV99hQ!J5JW3y6GhaJUqLfbEAzWIy4GJOhUkHQN4D5hEv3Outpzd54fN1Nt4LNKGnuRtMAepS_Nit-KLSUW98tVfFR0TmMVGQ$ > > Signed-off-by: Jing Zhang <renyu.zj@linux.alibaba.com> > Acked-by: Ian Rogers <irogers@google.com>
hmmm... you have made significant changes in this version (compared to previous), so I would not have picked up this tag. That's just my opinion.
As for the patchset org, I'd move the JSON change here into patch #2, and make this patch purely about add "slots" literal support for arm64.
> --- > tools/perf/arch/arm64/util/pmu.c | 22 ++++++++++++++++++++++ > tools/perf/pmu-events/arch/arm64/sbsa.json | 30 ++++++++++++++++++++++++++++++ > tools/perf/pmu-events/jevents.py | 2 ++ > tools/perf/util/expr.c | 5 +++++ > tools/perf/util/pmu.c | 5 +++++ > tools/perf/util/pmu.h | 1 + > 6 files changed, 65 insertions(+) > create mode 100644 tools/perf/pmu-events/arch/arm64/sbsa.json > > diff --git a/tools/perf/arch/arm64/util/pmu.c b/tools/perf/arch/arm64/util/pmu.c > index 477e513..227dadb 100644 > --- a/tools/perf/arch/arm64/util/pmu.c > +++ b/tools/perf/arch/arm64/util/pmu.c > @@ -3,6 +3,7 @@ > #include <internal/cpumap.h> > #include "../../../util/cpumap.h" > #include "../../../util/pmu.h" > +#include <api/fs/fs.h> > > const struct pmu_events_table *pmu_events_table__find(void) > { > @@ -24,3 +25,24 @@ const struct pmu_events_table *pmu_events_table__find(void) > > return NULL; > } > + > +int perf_pmu__get_slots(void) > +{ > + char path[PATH_MAX]; > + unsigned long long slots = 0; > + struct perf_pmu *pmu = NULL; > + > + while ((pmu = perf_pmu__scan(pmu)) != NULL) { > + if (is_pmu_core(pmu->name)) > + break; > + }
There is a lot in common with arm64's pmu_events_table__find() - can you factor it out? I also prefer how we check for homogeneous CPUs in pmu_events_table__find() (which you should do, also).
> + if (pmu) { > + scnprintf(path, PATH_MAX, > + EVENT_SOURCE_DEVICE_PATH "%s/caps/slots", pmu->name); > + /* The value of slots is not greater than INT_MAX, but sysfs__read_int > + * can't read value with 0x prefix, so use sysfs__read_ull instead. > + */ > + sysfs__read_ull(path, &slots); > + } > + return (int)slots; > +} > diff --git a/tools/perf/pmu-events/arch/arm64/sbsa.json b/tools/perf/pmu-events/arch/arm64/sbsa.json > new file mode 100644 > index 0000000..f678c37e > --- /dev/null > +++ b/tools/perf/pmu-events/arch/arm64/sbsa.json > @@ -0,0 +1,30 @@ > +[ > + { > + "MetricExpr": "stall_slot_frontend / (#slots * cpu_cycles)", > + "BriefDescription": "Frontend bound L1 topdown metric", > + "MetricGroup": "TopdownL1", > + "MetricName": "frontend_bound", > + "ScaleUnit": "100%" > + }, > + { > + "MetricExpr": "(1 - op_retired / op_spec) * (1 - stall_slot / (#slots * cpu_cycles))", > + "BriefDescription": "Bad speculation L1 topdown metric", > + "MetricGroup": "TopdownL1", > + "MetricName": "bad_speculation", > + "ScaleUnit": "100%" > + }, > + { > + "MetricExpr": "(op_retired / op_spec) * (1 - stall_slot / (#slots * cpu_cycles))", > + "BriefDescription": "Retiring L1 topdown metric", > + "MetricGroup": "TopdownL1", > + "MetricName": "retiring", > + "ScaleUnit": "100%" > + }, > + { > + "MetricExpr": "stall_slot_backend / (#slots * cpu_cycles)", > + "BriefDescription": "Backend Bound L1 topdown metric", > + "MetricGroup": "TopdownL1", > + "MetricName": "backend_bound", > + "ScaleUnit": "100%" > + } > +] > diff --git a/tools/perf/pmu-events/jevents.py b/tools/perf/pmu-events/jevents.py > index 4c398e0..0416b74 100755 > --- a/tools/perf/pmu-events/jevents.py > +++ b/tools/perf/pmu-events/jevents.py > @@ -358,6 +358,8 @@ def preprocess_arch_std_files(archpath: str) -> None: > for event in read_json_events(item.path, topic=''): > if event.name: > _arch_std_events[event.name.lower()] = event > + if event.metric_name: > + _arch_std_events[event.metric_name.lower()] = event > > > def print_events_table_prefix(tblname: str) -> None: > diff --git a/tools/perf/util/expr.c b/tools/perf/util/expr.c > index 00dcde3..3d67707 100644 > --- a/tools/perf/util/expr.c > +++ b/tools/perf/util/expr.c > @@ -19,6 +19,7 @@ > #include <linux/zalloc.h> > #include <ctype.h> > #include <math.h> > +#include "pmu.h" > > #ifdef PARSER_DEBUG > extern int expr_debug; > @@ -448,6 +449,10 @@ double expr__get_literal(const char *literal, const struct expr_scanner_ctx *ctx > result = topology->core_cpus_lists; > goto out; > } > + if (!strcmp("#slots", literal)) { > + result = perf_pmu__get_slots(); > + goto out; > + } > > pr_err("Unrecognized literal '%s'", literal); > out: > diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c > index 2bdeb89..d4cace2 100644 > --- a/tools/perf/util/pmu.c > +++ b/tools/perf/util/pmu.c > @@ -1993,3 +1993,8 @@ int perf_pmu__cpus_match(struct perf_pmu *pmu, struct perf_cpu_map *cpus, > *ucpus_ptr = unmatched_cpus; > return 0; > } > + > +int __weak perf_pmu__get_slots(void) > +{ > + return 0;
should this be NAN?
> +} > diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h > index 69ca000..a2f7df8 100644 > --- a/tools/perf/util/pmu.h > +++ b/tools/perf/util/pmu.h > @@ -259,4 +259,5 @@ int perf_pmu__cpus_match(struct perf_pmu *pmu, struct perf_cpu_map *cpus, > > char *pmu_find_real_name(const char *name); > char *pmu_find_alias_name(const char *name); > +int perf_pmu__get_slots(void);
I think that this name is a bit too vague. Maybe perf_pmu__cpu_cycles_per_slot() could be better.
> #endif /* __PMU_H */
Thanks, John
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