Messages in this thread | | | Subject | Re: [PATCH v2 6/7] perf pmu-events: Remember the perf_events_map for a PMU | From | Yang Jihong <> | Date | Mon, 16 Oct 2023 17:50:10 +0800 |
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Hello,
On 2023/10/13 1:56, Ian Rogers wrote: > strcmp_cpuid_str performs regular expression comparisons and so per > CPUID linear searches over the perf_events_map are expensive. Add a > helper function called map_for_pmu that does the search but also > caches the map specific to a PMU. As the PMU may differ, also cache > the CPUID string so that PMUs with the same CPUID string don't require > the linear search and regular expression comparisons. This speeds > loading PMUs as the search is done once per PMU to find the > appropriate tables. > > Signed-off-by: Ian Rogers <irogers@google.com> > --- > tools/perf/pmu-events/jevents.py | 109 ++++++++++++++++++++----------- > 1 file changed, 70 insertions(+), 39 deletions(-) > > diff --git a/tools/perf/pmu-events/jevents.py b/tools/perf/pmu-events/jevents.py > index 96dc74c90b20..3c091ab75305 100755 > --- a/tools/perf/pmu-events/jevents.py > +++ b/tools/perf/pmu-events/jevents.py > @@ -976,68 +976,99 @@ int pmu_metrics_table__for_each_metric(const struct pmu_metrics_table *table, > return 0; > } > > -const struct pmu_events_table *perf_pmu__find_events_table(struct perf_pmu *pmu) > +static const struct pmu_events_map *map_for_pmu(struct perf_pmu *pmu) > { > - const struct pmu_events_table *table = NULL; > - char *cpuid = perf_pmu__getcpuid(pmu); > + static struct { > + const struct pmu_events_map *map; > + struct perf_pmu *pmu; > + } last_result; > + static struct { > + const struct pmu_events_map *map; > + char *cpuid; > + } last_map_search; > + static bool has_last_result, has_last_map_search; > + const struct pmu_events_map *map = NULL; > + char *cpuid = NULL; > size_t i; > > - /* on some platforms which uses cpus map, cpuid can be NULL for > + if (has_last_result && last_result.pmu == pmu) > + return last_result.map; > + > + cpuid = perf_pmu__getcpuid(pmu); For the software pmu, we do not need to look for the events table. It seems that the software pmu can be filtered out in perf_pmu__lookup() to reduce unnecessary perf_pmu__find_events_table() calls.
I tried to submit a patch, please see if it helps: https://lore.kernel.org/all/20231016093309.726436-1-yangjihong1@huawei.com/
Thanks, Yang
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