Ian Rogers a24d9d9dc0 perf parse-events: Make legacy events lower priority than sysfs/JSON
The perf tool has previously made legacy events the priority so with
or without a PMU the legacy event would be opened:

  $ perf stat -e cpu-cycles,cpu/cpu-cycles/ true
  Using CPUID GenuineIntel-6-8D-1
  intel_pt default config: tsc,mtc,mtc_period=3,psb_period=3,pt,branch
  Attempting to add event pmu 'cpu' with 'cpu-cycles,' that may result in non-fatal errors
  After aliases, add event pmu 'cpu' with 'cpu-cycles,' that may result in non-fatal errors
  Control descriptor is not initialized
  ------------------------------------------------------------
  perf_event_attr:
    type                             0 (PERF_TYPE_HARDWARE)
    size                             136
    config                           0 (PERF_COUNT_HW_CPU_CYCLES)
    sample_type                      IDENTIFIER
    read_format                      TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING
    disabled                         1
    inherit                          1
    enable_on_exec                   1
    exclude_guest                    1
  ------------------------------------------------------------
  sys_perf_event_open: pid 833967  cpu -1  group_fd -1  flags 0x8 = 3
  ------------------------------------------------------------
  perf_event_attr:
    type                             0 (PERF_TYPE_HARDWARE)
    size                             136
    config                           0 (PERF_COUNT_HW_CPU_CYCLES)
    sample_type                      IDENTIFIER
    read_format                      TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING
    disabled                         1
    inherit                          1
    enable_on_exec                   1
    exclude_guest                    1
  ------------------------------------------------------------
  ...

Fixes to make hybrid/BIG.little PMUs behave correctly, ie as core PMUs
capable of opening legacy events on each, removing hard coded "cpu_core"
and "cpu_atom" Intel PMU names, etc. caused a behavioral difference on
Apple/ARM due to latent issues in the PMU driver reported in:
https://lore.kernel.org/lkml/08f1f185-e259-4014-9ca4-6411d5c1bc65@marcan.st/

As part of that report Mark Rutland <mark.rutland@arm.com> requested
that legacy events not be higher in priority when a PMU is specified
reversing what has until this change been perf's default behavior. With
this change the above becomes:

  $ perf stat -e cpu-cycles,cpu/cpu-cycles/ true
  Using CPUID GenuineIntel-6-8D-1
  Attempt to add: cpu/cpu-cycles=0/
  ..after resolving event: cpu/event=0x3c/
  Control descriptor is not initialized
  ------------------------------------------------------------
  perf_event_attr:
    type                             0 (PERF_TYPE_HARDWARE)
    size                             136
    config                           0 (PERF_COUNT_HW_CPU_CYCLES)
    sample_type                      IDENTIFIER
    read_format                      TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING
    disabled                         1
    inherit                          1
    enable_on_exec                   1
    exclude_guest                    1
  ------------------------------------------------------------
  sys_perf_event_open: pid 827628  cpu -1  group_fd -1  flags 0x8 = 3
  ------------------------------------------------------------
  perf_event_attr:
    type                             4 (PERF_TYPE_RAW)
    size                             136
    config                           0x3c
    sample_type                      IDENTIFIER
    read_format                      TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING
    disabled                         1
    inherit                          1
    enable_on_exec                   1
    exclude_guest                    1
  ------------------------------------------------------------
  ...

So the second event has become a raw event as
/sys/devices/cpu/events/cpu-cycles exists.

A fix was necessary to config_term_pmu in parse-events.c as check_alias
expansion needs to happen after config_term_pmu, and config_term_pmu may
need calling a second time because of this.

config_term_pmu is updated to not use the legacy event when the PMU has
such a named event (either from JSON or sysfs).

The bulk of this change is updating all of the parse-events test
expectations so that if a sysfs/JSON event exists for a PMU the test
doesn't fail - a further sign, if it were needed, that the legacy event
priority was a known and tested behavior of the perf tool.

Reported-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Hector Martin <marcan@marcan.st>
Tested-by: Marc Zyngier <maz@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20231123042922.834425-1-irogers@google.com
[ Initialize the 'alias_rewrote_terms' variable to false to address a clang warning ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2023-11-27 10:21:27 -03:00

271 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, bool *rewrote_terms,
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 */