From: Ian Rogers Date: Tue, 24 Jun 2025 23:18:35 +0000 (-0700) Subject: perf parse-events: Avoid scanning PMUs that can't contain events X-Git-Tag: io_uring-6.17-20250815~64^2~133 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=e1ec69ed5ded5351efb04218dcab9d79ab018ac5;p=linux-block.git perf parse-events: Avoid scanning PMUs that can't contain events Add perf_pmus__scan_for_event that only reads sysfs for pmus that could contain a given event. Signed-off-by: Ian Rogers Link: https://lore.kernel.org/r/20250624231837.179536-2-irogers@google.com Signed-off-by: Namhyung Kim --- diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c index d1965a7b97ed..4cd64ffa4fcd 100644 --- a/tools/perf/util/parse-events.c +++ b/tools/perf/util/parse-events.c @@ -490,7 +490,7 @@ int parse_events_add_cache(struct list_head *list, int *idx, const char *name, int ret = 0; struct evsel *first_wildcard_match = NULL; - while ((pmu = perf_pmus__scan(pmu)) != NULL) { + while ((pmu = perf_pmus__scan_for_event(pmu, name)) != NULL) { LIST_HEAD(config_terms); struct perf_event_attr attr; @@ -1681,7 +1681,8 @@ int parse_events_multi_pmu_add(struct parse_events_state *parse_state, INIT_LIST_HEAD(list); - while ((pmu = perf_pmus__scan(pmu)) != NULL) { + while ((pmu = perf_pmus__scan_for_event(pmu, event_name)) != NULL) { + if (parse_events__filter_pmu(parse_state, pmu)) continue; @@ -1760,19 +1761,21 @@ int parse_events_multi_pmu_add_or_add_pmu(struct parse_events_state *parse_state pmu = NULL; /* Failed to add, try wildcard expansion of event_or_pmu as a PMU name. */ - while ((pmu = perf_pmus__scan(pmu)) != NULL) { - if (!parse_events__filter_pmu(parse_state, pmu) && - perf_pmu__wildcard_match(pmu, event_or_pmu)) { - if (!parse_events_add_pmu(parse_state, *listp, pmu, - const_parsed_terms, - first_wildcard_match, - /*alternate_hw_config=*/PERF_COUNT_HW_MAX)) { - ok++; - parse_state->wild_card_pmus = true; - } - if (first_wildcard_match == NULL) - first_wildcard_match = - container_of((*listp)->prev, struct evsel, core.node); + while ((pmu = perf_pmus__scan_matching_wildcard(pmu, event_or_pmu)) != NULL) { + + if (parse_events__filter_pmu(parse_state, pmu)) + continue; + + if (!parse_events_add_pmu(parse_state, *listp, pmu, + const_parsed_terms, + first_wildcard_match, + /*alternate_hw_config=*/PERF_COUNT_HW_MAX)) { + ok++; + parse_state->wild_card_pmus = true; + } + if (first_wildcard_match == NULL) { + first_wildcard_match = + container_of((*listp)->prev, struct evsel, core.node); } } if (ok) diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c index 3bbd26fec78a..e0094f56b8e7 100644 --- a/tools/perf/util/pmus.c +++ b/tools/perf/util/pmus.c @@ -19,6 +19,7 @@ #include "tool_pmu.h" #include "print-events.h" #include "strbuf.h" +#include "string2.h" /* * core_pmus: A PMU belongs to core_pmus if it's name is "cpu" or it's sysfs @@ -350,6 +351,82 @@ struct perf_pmu *perf_pmus__scan_core(struct perf_pmu *pmu) return NULL; } +struct perf_pmu *perf_pmus__scan_for_event(struct perf_pmu *pmu, const char *event) +{ + bool use_core_pmus = !pmu || pmu->is_core; + + if (!pmu) { + /* Hwmon filename values that aren't used. */ + enum hwmon_type type; + int number; + /* + * Core PMUs, other sysfs PMUs and tool PMU can take all event + * types or aren't wother optimizing for. + */ + unsigned int to_read_pmus = PERF_TOOL_PMU_TYPE_PE_CORE_MASK | + PERF_TOOL_PMU_TYPE_PE_OTHER_MASK | + PERF_TOOL_PMU_TYPE_TOOL_MASK; + + /* Could the event be a hwmon event? */ + if (parse_hwmon_filename(event, &type, &number, /*item=*/NULL, /*alarm=*/NULL)) + to_read_pmus |= PERF_TOOL_PMU_TYPE_HWMON_MASK; + + pmu_read_sysfs(to_read_pmus); + pmu = list_prepare_entry(pmu, &core_pmus, list); + } + if (use_core_pmus) { + list_for_each_entry_continue(pmu, &core_pmus, list) + return pmu; + + pmu = NULL; + pmu = list_prepare_entry(pmu, &other_pmus, list); + } + list_for_each_entry_continue(pmu, &other_pmus, list) + return pmu; + return NULL; +} + +struct perf_pmu *perf_pmus__scan_matching_wildcard(struct perf_pmu *pmu, const char *wildcard) +{ + bool use_core_pmus = !pmu || pmu->is_core; + + if (!pmu) { + /* + * Core PMUs, other sysfs PMUs and tool PMU can have any name or + * aren't wother optimizing for. + */ + unsigned int to_read_pmus = PERF_TOOL_PMU_TYPE_PE_CORE_MASK | + PERF_TOOL_PMU_TYPE_PE_OTHER_MASK | + PERF_TOOL_PMU_TYPE_TOOL_MASK; + + /* + * Hwmon PMUs have an alias from a sysfs name like hwmon0, + * hwmon1, etc. or have a name of hwmon_. They therefore + * can only have a wildcard match if the wildcard begins with + * "hwmon". + */ + if (strisglob(wildcard) || + (strlen(wildcard) >= 5 && strncmp("hwmon", wildcard, 5) == 0)) + to_read_pmus |= PERF_TOOL_PMU_TYPE_HWMON_MASK; + + pmu_read_sysfs(to_read_pmus); + pmu = list_prepare_entry(pmu, &core_pmus, list); + } + if (use_core_pmus) { + list_for_each_entry_continue(pmu, &core_pmus, list) { + if (perf_pmu__wildcard_match(pmu, wildcard)) + return pmu; + } + pmu = NULL; + pmu = list_prepare_entry(pmu, &other_pmus, list); + } + list_for_each_entry_continue(pmu, &other_pmus, list) { + if (perf_pmu__wildcard_match(pmu, wildcard)) + return pmu; + } + return NULL; +} + static struct perf_pmu *perf_pmus__scan_skip_duplicates(struct perf_pmu *pmu) { bool use_core_pmus = !pmu || pmu->is_core; diff --git a/tools/perf/util/pmus.h b/tools/perf/util/pmus.h index 8def20e615ad..2794d8c3a466 100644 --- a/tools/perf/util/pmus.h +++ b/tools/perf/util/pmus.h @@ -19,6 +19,8 @@ struct perf_pmu *perf_pmus__find_by_type(unsigned int type); struct perf_pmu *perf_pmus__scan(struct perf_pmu *pmu); struct perf_pmu *perf_pmus__scan_core(struct perf_pmu *pmu); +struct perf_pmu *perf_pmus__scan_for_event(struct perf_pmu *pmu, const char *event); +struct perf_pmu *perf_pmus__scan_matching_wildcard(struct perf_pmu *pmu, const char *wildcard); const struct perf_pmu *perf_pmus__pmu_for_pmu_filter(const char *str);