Commit e1ec69ed authored by Ian Rogers's avatar Ian Rogers Committed by Namhyung Kim
Browse files

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: default avatarIan Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250624231837.179536-2-irogers@google.com


Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
parent 9c9f4a27

tools/perf/util/parse-events.c

+18 −15
Original line number Diff line number Diff line
@@ -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;
@@ -1760,9 +1761,11 @@ 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)) {

	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,
@@ -1770,7 +1773,7 @@ int parse_events_multi_pmu_add_or_add_pmu(struct parse_events_state *parse_state 
			ok++;

			parse_state->wild_card_pmus = true;

		}

			if (first_wildcard_match == NULL)

		if (first_wildcard_match == NULL) {

			first_wildcard_match =

				container_of((*listp)->prev, struct evsel, core.node);

		}

tools/perf/util/pmus.c

+77 −0
Original line number Diff line number Diff line
@@ -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_<name>. 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;

tools/perf/util/pmus.h

+2 −0
Original line number Diff line number Diff line
@@ -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);