STRUCT PERF_PMU(9)

🌸 NAME 🌸

struct perf_pmu — and bestie, the tagline slot is literally empty in the original. No description, no subtitle, just the name and a whole lot of mystique. We move anyway 💅

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✨ SYNOPSIS ✨

Okay so here's the whole struct, copied exactly, no cap:

struct perf_pmu {
    const char *name;
    char *alias_name;
    const char *id;
    __u32 type;
    bool selectable;
    bool is_core;
    bool is_uncore;
    bool auxtrace;
    bool formats_checked;
    bool config_masks_present;
    bool config_masks_computed;
    int max_precise;
    void (*perf_event_attr_init_default)(const struct perf_pmu *pmu,
struct perf_event_attr *attr);
    struct perf_cpu_map *cpus;
    struct list_head format;
    struct hashmap *aliases;
    const struct pmu_events_table *events_table;
    uint32_t sysfs_aliases;
    uint32_t cpu_json_aliases;
    uint32_t sys_json_aliases;
    uint32_t cpu_common_json_aliases;
    bool sysfs_aliases_loaded;
    bool cpu_aliases_added;
    bool caps_initialized;
    u32 nr_caps;
    struct list_head caps;
    struct list_head list;
    __u64 config_masks[PERF_PMU_FORMAT_VALUE_CONFIG_END];
    struct {
      bool exclude_guest;
      bool checked;
    } missing_features;
    struct perf_mem_event *mem_events;
 };

(That line break in perf_event_attr_init_default's signature? That's how it is in the original, I'm not touching it 🫶)

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🎀 Members 🎀

Time for the member-by-member tour, grab a snack 🍓

• name — the name of the PMU, like "cpu".
• alias_name — optional alternate name for the PMU, determined in architecture specific code.
• id — optional PMU identifier, read from <sysfs>/bus/event_source/devices/<name>/identifier.
• type — perf event attributed type value, read from <sysfs>/bus/event_source/devices/<name>/type.
• selectable — can the PMU name be selected as if it were an event?
• 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. Heads up: there may be >1 core PMU on systems like Intel hybrid 👀
• is_uncore — is the PMU not within the CPU core? Determined by the presence of <sysfs>/bus/event_source/devices/<name>/cpumask.
• auxtrace — are events auxiliary events? Determined in architecture specific code.
• formats_checked — only check the PMU's formats are valid for perf_event_attr once. Efficiency slay ✨
• config_masks_present — are there config format values?
• config_masks_computed — set when masks are lazily computed.
• max_precise — number of levels of :ppp precision supported by the PMU, read from <sysfs>/bus/event_source/devices/<name>/caps/max_precise.
• perf_event_attr_init_default — optional function to default initialize PMU specific parts of the perf_event_attr.
• cpus — empty, or the contents of either of these two:
  • <sysfs>/bus/event_source/devices/<name>/cpumask.
  • <sysfs>/bus/event_source/devices/<cpu>/cpus.
• format — holds the contents of files read from <sysfs>/bus/event_source/devices/<name>/format/. Those contents specify which event parameter changes what config, config1 or config2 bits.
• 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.
• events_table — the events table for json events in pmu-events.c.
• sysfs_aliases — number of sysfs aliases loaded.
• cpu_json_aliases — number of json event aliases loaded specific to the CPUID.
• sys_json_aliases — number of json event aliases loaded matching the PMU's identifier.
• cpu_common_json_aliases — number of json events that overlapped with sysfs when loading all sysfs events.
• sysfs_aliases_loaded — are sysfs aliases loaded from disk?
• cpu_aliases_added — have all json events table entries for the PMU been added?
• caps_initialized — has the list caps been initialized?
• nr_caps — the length of the list caps.
• caps — holds the contents of files read from <sysfs>/bus/event_source/devices/<name>/caps/.

So about those caps contents, bestie: they're pairs of the filename with the value of its contents. For example, max_precise (see above 👆) may have a value of 3. Periodt.

• list — element on pmus list in pmu.c.
• config_masks — derived from the PMU's format data, the bits that are valid within the config value.
• missing_features — features to inhibit when events on this PMU are opened. (It's a nested struct with exclude_guest and checked inside, iykyk 👑)
• mem_events — list of the supported mem events.

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🦋 SEE ALSO 🦋

Go read these next, fr fr:

• Kernel file ./tools/perf/util/pmu.h
• struct perf_pmu_format(9)

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Ok that's the whole thing, no notes, you ate 💖

Lives in ./tools/perf/util, dated October 2026 — catch you in the next manpage, mwah 🧚‍♀️🌈