Messages in this thread | | | From | Ian Rogers <> | Date | Mon, 14 Nov 2022 06:09:17 -0800 | Subject | Re: [PATCH v1 1/9] perf pmu: Add documentation |
| |
On Mon, Nov 14, 2022 at 5:40 AM Liang, Kan <kan.liang@linux.intel.com> wrote: > > > > On 2022-11-14 2:51 a.m., Ian Rogers wrote: > > 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 | 14 ++++++ > > tools/perf/util/pmu.h | 105 +++++++++++++++++++++++++++++++++++++++--- > > 2 files changed, 113 insertions(+), 6 deletions(-) > > > > diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c > > index 6a86e6af0903..a8f9f47c6ed9 100644 > > --- a/tools/perf/util/pmu.c > > +++ b/tools/perf/util/pmu.c > > @@ -31,10 +31,24 @@ > > > > struct perf_pmu perf_pmu__fake; > > > > +/** > > + * 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 { > > + /** The modifier/file name. */ > > char *name; > > + /** > > + * 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; > > + /** Which config bits are set by this format value. */ > > DECLARE_BITMAP(bits, PERF_PMU_FORMAT_BITS); > > + /** Element on list within struct perf_pmu. */ > > struct list_head list; > > }; > > > > diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h > > index 68e15c38ae71..29571c0f9d15 100644 > > --- a/tools/perf/util/pmu.h > > +++ b/tools/perf/util/pmu.h > > @@ -34,30 +34,91 @@ struct perf_pmu_caps { > > }; > > > > struct perf_pmu { > > + /** The name of the PMU such as "cpu". */ > > char *name; > > + /** > > + * Optional alternate name for the PMU determined in architecture > > + * specific code. > > + */ > > char *alias_name; > > + /** > > + * Optional PMU identifier read from > > + * <sysfs>/bus/event_source/devices/<name>/identifier. > > + */ > > char *id; > > + /** > > + * Perf event attributed type value, read from > > + * <sysfs>/bus/event_source/devices/<name>/type. > > + */ > > __u32 type; > > + /** > > + * Can the PMU name be selected as if it were an event? > > + */ > > bool selectable; > > + /** > > + * Is the PMU not within the CPU core? Determined by the presence of > > + * <sysfs>/bus/event_source/devices/<name>/cpumask. > > + */ > > bool is_uncore; > > + /** Is the PMU name either cpu_core or cpu_atom. */ > > I don't think we want to limit the hybrid names only to cpu_core or > cpu_atom. Maybe something as below? > /* Is a hybrid CPU PMU, e.g., cpu_core, cpu_atom. */
Currently the hybrid code only works for cpu_core or cpu_atom, a limitation of its implementation. As pointed out in a later patch, this bool isn't being used when it could be and I think we can work to remove it. It would be possible to remove all uses of this with perf_pmu__is_hybrid. As such I think it may be useful to mark the hybrid variables in struct perf_pmu as deprecated while we work to replace their use with more generic just any PMU code.
Thanks, Ian
> Thanks, > Kan > > > bool is_hybrid; > > + /** > > + * Are events auxiliary events? Determined in architecture specific > > + * code. > > + */ > > bool auxtrace; > > + /** > > + * Number of levels of :ppp precision supported by the PMU, read from > > + * <sysfs>/bus/event_source/devices/<name>/caps/max_precise. > > + */ > > int max_precise; > > + /** > > + * Optional default perf_event_attr determined in architecture specific > > + * code. > > + */ > > struct perf_event_attr *default_config; > > + /** > > + * 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 */ > > + /** > > + * 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; > > + /** > > + * 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; > > + /** Has the list caps been initialized? */ > > bool caps_initialized; > > + /** The length of the list caps. */ > > u32 nr_caps; > > - struct list_head caps; /* HEAD struct perf_pmu_caps -> list */ > > - struct list_head list; /* ELEM */ > > + /** > > + * 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; > > + /** Element on pmus list in pmu.c. */ > > + struct list_head list; > > + /** Element on perf_pmu__hybrid_pmus. */ > > struct list_head hybrid_list; > > > > + /** Features to inhibit when events on this PMU are opened. */ > > struct { > > + /** Disables perf_event_attr exclude_guest and exclude_host. */ > > bool exclude_guest; > > } missing_features; > > }; > > > > +/** A special global PMU used for testing. */ > > extern struct perf_pmu perf_pmu__fake; > > > > struct perf_pmu_info { > > @@ -71,21 +132,53 @@ struct perf_pmu_info { > > > > #define UNIT_MAX_LEN 31 /* max length for event unit name */ > > > > +/** > > + * An event either read from sysfs or builtin in pmu-events.c, created by > > + * parsing the pmu-events json files. > > + */ > > struct perf_pmu_alias { > > char *name; > > + /** Optional short description of the event. */ > > char *desc; > > + /** Optional long description. */ > > char *long_desc; > > + /** > > + * Optional topic such as cache or pipeline, particularly for json > > + * events. > > + */ > > char *topic; > > + /** Comma separated parameter list. */ > > char *str; > > - struct list_head terms; /* HEAD struct parse_events_term -> list */ > > - struct list_head list; /* ELEM */ > > + /** Owned list of the original parsed parameters. */ > > + struct list_head terms; > > + /** List element of struct perf_pmu aliases. */ > > + struct list_head list; > > + /** Units for the event, such as bytes or cache lines. */ > > char unit[UNIT_MAX_LEN+1]; > > + /** Value to scale read counter values by. */ > > double scale; > > + /** > > + * 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; > > + /** > > + * Does the file > > + * <sysfs>/bus/event_source/devices/<pmu_name>/events/<name>.snapshot > > + * exist and have the value 1. > > + */ > > bool snapshot; > > + /** Is the event hidden and so not shown in perf list by default. */ > > bool deprecated; > > + /** > > + * A metric expression associated with an event. Doing this makes little > > + * sense due to scale and unit applying to both. > > + */ > > char *metric_expr; > > + /** A name for the metric. unit applying to both. */ > > char *metric_name; > > + /** The name copied from struct perf_pmu. */ > > char *pmu_name; > > }; > >
| |