linux-stable/tools/perf/util/pmu.h
Ian Rogers 0197da7aff perf pmu: Lazily compute default config
The default config is computed during creation of the PMU and may do
things like scanning sysfs, when the PMU may just be used as part of
scanning. Change default_config to perf_event_attr_init_default, a
callback that is used when a default config needs initializing. This
avoids holding onto the memory for a perf_event_attr and copying.

On a tigerlake laptop running the pmu-scan benchmark:

Before:
Running 'internals/pmu-scan' benchmark:
Computing performance of sysfs PMU event scan for 100 times
  Average core PMU scanning took: 28.780 usec (+- 0.503 usec)
  Average PMU scanning took: 283.480 usec (+- 18.471 usec)
Number of openat syscalls: 30,227

After:
Running 'internals/pmu-scan' benchmark:
Computing performance of sysfs PMU event scan for 100 times
  Average core PMU scanning took: 27.880 usec (+- 0.169 usec)
  Average PMU scanning took: 245.260 usec (+- 15.758 usec)
Number of openat syscalls: 28,914

Over 3 runs it is a nearly 12% reduction in execution time and a 4.3%
of openat calls.

Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: James Clark <james.clark@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Will Deacon <will@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Jing Zhang <renyu.zj@linux.alibaba.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: John Garry <john.g.garry@oracle.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: coresight@lists.linaro.org
Link: https://lore.kernel.org/r/20231012175645.1849503-8-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2023-10-17 12:40:50 -07:00

269 lines
8.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __PMU_H
#define __PMU_H
#include <linux/bitmap.h>
#include <linux/compiler.h>
#include <linux/perf_event.h>
#include <linux/list.h>
#include <stdbool.h>
#include <stdio.h>
#include "parse-events.h"
#include "pmu-events/pmu-events.h"
struct evsel_config_term;
struct perf_cpu_map;
struct print_callbacks;
enum {
PERF_PMU_FORMAT_VALUE_CONFIG,
PERF_PMU_FORMAT_VALUE_CONFIG1,
PERF_PMU_FORMAT_VALUE_CONFIG2,
PERF_PMU_FORMAT_VALUE_CONFIG3,
PERF_PMU_FORMAT_VALUE_CONFIG_END,
};
#define PERF_PMU_FORMAT_BITS 64
#define MAX_PMU_NAME_LEN 128
struct perf_event_attr;
struct perf_pmu_caps {
char *name;
char *value;
struct list_head list;
};
/**
* struct perf_pmu
*/
struct perf_pmu {
/** @name: The name of the PMU such as "cpu". */
const char *name;
/**
* @alias_name: Optional alternate name for the PMU determined in
* architecture specific code.
*/
char *alias_name;
/**
* @id: Optional PMU identifier read from
* <sysfs>/bus/event_source/devices/<name>/identifier.
*/
const char *id;
/**
* @type: Perf event attributed type value, read from
* <sysfs>/bus/event_source/devices/<name>/type.
*/
__u32 type;
/**
* @selectable: Can the PMU name be selected as if it were an event?
*/
bool selectable;
/**
* @is_core: Is the PMU the core CPU PMU? Determined by the name being
* "cpu" or by the presence of
* <sysfs>/bus/event_source/devices/<name>/cpus. There may be >1 core
* PMU on systems like Intel hybrid.
*/
bool is_core;
/**
* @is_uncore: Is the PMU not within the CPU core? Determined by the
* presence of <sysfs>/bus/event_source/devices/<name>/cpumask.
*/
bool is_uncore;
/**
* @auxtrace: Are events auxiliary events? Determined in architecture
* specific code.
*/
bool auxtrace;
/**
* @formats_checked: Only check PMU's formats are valid for
* perf_event_attr once.
*/
bool formats_checked;
/** @config_masks_present: Are there config format values? */
bool config_masks_present;
/** @config_masks_computed: Set when masks are lazily computed. */
bool config_masks_computed;
/**
* @max_precise: Number of levels of :ppp precision supported by the
* PMU, read from
* <sysfs>/bus/event_source/devices/<name>/caps/max_precise.
*/
int max_precise;
/**
* @perf_event_attr_init_default: Optional function to default
* initialize PMU specific parts of the perf_event_attr.
*/
void (*perf_event_attr_init_default)(const struct perf_pmu *pmu,
struct perf_event_attr *attr);
/**
* @cpus: Empty or the contents of either of:
* <sysfs>/bus/event_source/devices/<name>/cpumask.
* <sysfs>/bus/event_source/devices/<cpu>/cpus.
*/
struct perf_cpu_map *cpus;
/**
* @format: Holds the contents of files read from
* <sysfs>/bus/event_source/devices/<name>/format/. The contents specify
* which event parameter changes what config, config1 or config2 bits.
*/
struct list_head format;
/**
* @aliases: List of struct perf_pmu_alias. Each alias corresponds to an
* event read from <sysfs>/bus/event_source/devices/<name>/events/ or
* from json events in pmu-events.c.
*/
struct list_head aliases;
/**
* @events_table: The events table for json events in pmu-events.c.
*/
const struct pmu_events_table *events_table;
/** @sysfs_aliases: Number of sysfs aliases loaded. */
uint32_t sysfs_aliases;
/** @sysfs_aliases: Number of json event aliases loaded. */
uint32_t loaded_json_aliases;
/** @sysfs_aliases_loaded: Are sysfs aliases loaded from disk? */
bool sysfs_aliases_loaded;
/**
* @cpu_aliases_added: Have all json events table entries for the PMU
* been added?
*/
bool cpu_aliases_added;
/** @caps_initialized: Has the list caps been initialized? */
bool caps_initialized;
/** @nr_caps: The length of the list caps. */
u32 nr_caps;
/**
* @caps: Holds the contents of files read from
* <sysfs>/bus/event_source/devices/<name>/caps/.
*
* The contents are pairs of the filename with the value of its
* contents, for example, max_precise (see above) may have a value of 3.
*/
struct list_head caps;
/** @list: Element on pmus list in pmu.c. */
struct list_head list;
/**
* @config_masks: Derived from the PMU's format data, bits that are
* valid within the config value.
*/
__u64 config_masks[PERF_PMU_FORMAT_VALUE_CONFIG_END];
/**
* @missing_features: Features to inhibit when events on this PMU are
* opened.
*/
struct {
/**
* @exclude_guest: Disables perf_event_attr exclude_guest and
* exclude_host.
*/
bool exclude_guest;
} missing_features;
};
/** @perf_pmu__fake: A special global PMU used for testing. */
extern struct perf_pmu perf_pmu__fake;
struct perf_pmu_info {
const char *unit;
double scale;
bool per_pkg;
bool snapshot;
};
struct pmu_event_info {
const struct perf_pmu *pmu;
const char *name;
const char* alias;
const char *scale_unit;
const char *desc;
const char *long_desc;
const char *encoding_desc;
const char *topic;
const char *pmu_name;
const char *str;
bool deprecated;
};
typedef int (*pmu_event_callback)(void *state, struct pmu_event_info *info);
void pmu_add_sys_aliases(struct perf_pmu *pmu);
int perf_pmu__config(struct perf_pmu *pmu, struct perf_event_attr *attr,
struct parse_events_terms *head_terms,
struct parse_events_error *error);
int perf_pmu__config_terms(const struct perf_pmu *pmu,
struct perf_event_attr *attr,
struct parse_events_terms *terms,
bool zero, struct parse_events_error *error);
__u64 perf_pmu__format_bits(struct perf_pmu *pmu, const char *name);
int perf_pmu__format_type(struct perf_pmu *pmu, const char *name);
int perf_pmu__check_alias(struct perf_pmu *pmu, struct parse_events_terms *head_terms,
struct perf_pmu_info *info, struct parse_events_error *err);
int perf_pmu__find_event(struct perf_pmu *pmu, const char *event, void *state, pmu_event_callback cb);
int perf_pmu__format_parse(struct perf_pmu *pmu, int dirfd, bool eager_load);
void perf_pmu_format__set_value(void *format, int config, unsigned long *bits);
bool perf_pmu__has_format(const struct perf_pmu *pmu, const char *name);
bool is_pmu_core(const char *name);
bool perf_pmu__supports_legacy_cache(const struct perf_pmu *pmu);
bool perf_pmu__auto_merge_stats(const struct perf_pmu *pmu);
bool perf_pmu__have_event(struct perf_pmu *pmu, const char *name);
size_t perf_pmu__num_events(struct perf_pmu *pmu);
int perf_pmu__for_each_event(struct perf_pmu *pmu, bool skip_duplicate_pmus,
void *state, pmu_event_callback cb);
bool pmu__name_match(const struct perf_pmu *pmu, const char *pmu_name);
/**
* perf_pmu_is_software - is the PMU a software PMU as in it uses the
* perf_sw_context in the kernel?
*/
bool perf_pmu__is_software(const struct perf_pmu *pmu);
FILE *perf_pmu__open_file(const struct perf_pmu *pmu, const char *name);
FILE *perf_pmu__open_file_at(const struct perf_pmu *pmu, int dirfd, const char *name);
int perf_pmu__scan_file(const struct perf_pmu *pmu, const char *name, const char *fmt, ...)
__scanf(3, 4);
int perf_pmu__scan_file_at(const struct perf_pmu *pmu, int dirfd, const char *name,
const char *fmt, ...) __scanf(4, 5);
bool perf_pmu__file_exists(const struct perf_pmu *pmu, const char *name);
int perf_pmu__test(void);
void perf_pmu__arch_init(struct perf_pmu *pmu);
void pmu_add_cpu_aliases_table(struct perf_pmu *pmu,
const struct pmu_events_table *table);
char *perf_pmu__getcpuid(struct perf_pmu *pmu);
const struct pmu_metrics_table *pmu_metrics_table__find(void);
bool pmu_uncore_identifier_match(const char *compat, const char *id);
int perf_pmu__convert_scale(const char *scale, char **end, double *sval);
int perf_pmu__caps_parse(struct perf_pmu *pmu);
void perf_pmu__warn_invalid_config(struct perf_pmu *pmu, __u64 config,
const char *name, int config_num,
const char *config_name);
void perf_pmu__warn_invalid_formats(struct perf_pmu *pmu);
int perf_pmu__match(const char *pattern, const char *name, const char *tok);
double perf_pmu__cpu_slots_per_cycle(void);
int perf_pmu__event_source_devices_scnprintf(char *pathname, size_t size);
int perf_pmu__pathname_scnprintf(char *buf, size_t size,
const char *pmu_name, const char *filename);
int perf_pmu__event_source_devices_fd(void);
int perf_pmu__pathname_fd(int dirfd, const char *pmu_name, const char *filename, int flags);
struct perf_pmu *perf_pmu__lookup(struct list_head *pmus, int dirfd, const char *lookup_name);
struct perf_pmu *perf_pmu__create_placeholder_core_pmu(struct list_head *core_pmus);
void perf_pmu__delete(struct perf_pmu *pmu);
struct perf_pmu *perf_pmus__find_core_pmu(void);
#endif /* __PMU_H */