STRUCT PERF_PMU_FORMAT(9)

💅 struct perf_pmu_format(9) — kernel API manual, bestie edition ✨

Okay so picture this: it's a kernel API manual page, right, and it's here to explain struct perf_pmu_format — the little icon that holds the values from a format file that got read from <sysfs>/devices/cpu/format/ and is now chilling inside struct perf_pmu. Yeah. She's a keeper. 🎀

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✨ SYNOPSIS ✨

struct perf_pmu_format {
    struct list_head list;
    unsigned long bits[BITS_TO_LONGS( PERF_PMU_FORMAT_BITS)];
    char *name;
    u16 value;
    bool loaded;
 };

ngl that array declaration is giving BITS_TO_LONGS( PERF_PMU_FORMAT_BITS) with the space and everything — copy it exactly as-is, bestie, we do not editorialize in code blocks. 💀

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🌸 Members 🌸

• list — this is her element on the list that lives inside struct perf_pmu. She's on a list! She's booked and busy! 🦋
• bits — the config bits that this format value actually sets. Which ones? These ones. Specifically these. 👑
• name — the modifier/file name, literally just the name, no notes. ✨
• value — which config value this format relates to. Supported values run from PERF_PMU_FORMAT_VALUE_CONFIG to PERF_PMU_FORMAT_VALUE_CONFIG_END. That's the range, don't go outside it. 🙈
• loaded — has the contents been loaded/parsed? A whole boolean for that question. Yes or no. That's the vibe check. ⭐

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💖 Description 💖

So like, a real example, because examples ate:

Say the contents of <sysfs>/devices/cpu/format/event is literally the string "config:0-7". When that gets represented here, you get:

• name="event"
• value=PERF_PMU_FORMAT_VALUE_CONFIG
• and bits 0 to 7 will be set

That's it. That's the whole transformation. She read the file, she parsed it, she set the bits, she slayed. 💅🔥

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🌈 SEE ALSO 🌈

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

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🫶 That's a wrap, bestie! This page came from ./tools/perf/util, dated October 2026, and it's the struct perf_pmu_format(9) page — go forth and read your format files with main character energy. 💜🎀