[v3,02/10] perf pmu: Add documentation
Commit Message
Add documentation to struct perf_pmu and the associated structs of
perf_pmu_alias and perf_pmu_format.
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/util/pmu.c | 16 ++++++
tools/perf/util/pmu.h | 122 +++++++++++++++++++++++++++++++++++++++---
2 files changed, 132 insertions(+), 6 deletions(-)
@@ -31,10 +31,26 @@
struct perf_pmu perf_pmu__fake;
+/**
+ * struct perf_pmu_format - Values from a format file read from
+ * <sysfs>/devices/cpu/format/ held in struct perf_pmu.
+ *
+ * For example, the contents of <sysfs>/devices/cpu/format/event may be
+ * "config:0-7" and will be represented here as name="event",
+ * value=PERF_PMU_FORMAT_VALUE_CONFIG and bits 0 to 7 will be set.
+ */
struct perf_pmu_format {
+ /** @name: The modifier/file name. */
char *name;
+ /**
+ * @value : Which config value the format relates to. Supported values
+ * are from PERF_PMU_FORMAT_VALUE_CONFIG to
+ * PERF_PMU_FORMAT_VALUE_CONFIG_END.
+ */
int value;
+ /** @bits: Which config bits are set by this format value. */
DECLARE_BITMAP(bits, PERF_PMU_FORMAT_BITS);
+ /** @list: Element on list within struct perf_pmu. */
struct list_head list;
};
@@ -33,30 +33,101 @@ struct perf_pmu_caps {
struct list_head list;
};
+/**
+ * struct perf_pmu - hi
+ */
struct perf_pmu {
+ /** @name: The name of the PMU such as "cpu". */
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.
+ */
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_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;
+ /**
+ * @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;
+ /**
+ * @default_config: Optional default perf_event_attr determined in
+ * architecture specific code.
+ */
struct perf_event_attr *default_config;
+ /**
+ * @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;
- struct list_head format; /* HEAD struct perf_pmu_format -> list */
- struct list_head aliases; /* HEAD struct perf_pmu_alias -> list */
+ /**
+ * @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;
+ /** @caps_initialized: Has the list caps been initialized? */
bool caps_initialized;
+ /** @nr_caps: The length of the list caps. */
u32 nr_caps;
- struct list_head caps; /* HEAD struct perf_pmu_caps -> list */
- struct list_head list; /* ELEM */
+ /**
+ * @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;
+ /** @hybrid_list: Element on perf_pmu__hybrid_pmus. */
struct list_head hybrid_list;
+ /**
+ * @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 {
@@ -70,21 +141,60 @@ struct perf_pmu_info {
#define UNIT_MAX_LEN 31 /* max length for event unit name */
+/**
+ * struct perf_pmu_alias - An event either read from sysfs or builtin in
+ * pmu-events.c, created by parsing the pmu-events json files.
+ */
struct perf_pmu_alias {
+ /** @name: Name of the event like "mem-loads". */
char *name;
+ /** @desc: Optional short description of the event. */
char *desc;
+ /** @long_desc: Optional long description. */
char *long_desc;
+ /**
+ * @topic: Optional topic such as cache or pipeline, particularly for
+ * json events.
+ */
char *topic;
+ /**
+ * @str: Comma separated parameter list like
+ * "event=0xcd,umask=0x1,ldlat=0x3".
+ */
char *str;
- struct list_head terms; /* HEAD struct parse_events_term -> list */
- struct list_head list; /* ELEM */
+ /** @terms: Owned list of the original parsed parameters. */
+ struct list_head terms;
+ /** @list: List element of struct perf_pmu aliases. */
+ struct list_head list;
+ /** @unit: Units for the event, such as bytes or cache lines. */
char unit[UNIT_MAX_LEN+1];
+ /** @scale: Value to scale read counter values by. */
double scale;
+ /**
+ * @per_pkg: Does the file
+ * <sysfs>/bus/event_source/devices/<pmu_name>/events/<name>.per-pkg or
+ * equivalent json value exist and have the value 1.
+ */
bool per_pkg;
+ /**
+ * @snapshot: Does the file
+ * <sysfs>/bus/event_source/devices/<pmu_name>/events/<name>.snapshot
+ * exist and have the value 1.
+ */
bool snapshot;
+ /**
+ * @deprecated: Is the event hidden and so not shown in perf list by
+ * default.
+ */
bool deprecated;
+ /**
+ * @metric_expr: A metric expression associated with an event. Doing
+ * this makes little sense due to scale and unit applying to both.
+ */
char *metric_expr;
+ /** @metric_name: A name for the metric. unit applying to both. */
char *metric_name;
+ /** @pmu_name: The name copied from struct perf_pmu. */
char *pmu_name;
};