STRUCT PERF_OPEN_PROPERTIES(9)

📦 version 7.3.1, in nixpkgs unstable

💜 struct perf_open_properties(9) — the Kernel API Manual, bestie edition ✨

okay so we're in the kernel API manual, section 9, and today's main character is struct perf_open_properties 🎀 — literally the struct where all your validated properties hang out before you open a stream. iykyk.

🌸 NAME 🌸

struct perf_open_properties — for validated properties given to open a stream. that's it, that's the vibe. no cap. 💅

✨ SYNOPSIS ✨

here's the whole squad, member by member, no skips:

struct perf_open_properties {
    u32 sample_flags;
    u64 single_context:1;
    u64 hold_preemption:1;
    u64 ctx_handle;
    int metrics_set;
    int oa_format;
    bool oa_periodic;
    int oa_period_exponent;
    struct intel_engine_cs *engine;
    bool has_sseu;
    struct intel_sseu sseu;
    u64 poll_oa_period;
 };

(yeah there's a little extra space before that closing brace, she's just standing like that, leave her alone 🙈)

🦋 Members 🦋

okay bestie, meet the members one by one:

  • sample_flags — the DRM_I915_PERF_PROP_SAMPLE_* properties get tracked as flags in here. flags! like a little checklist of sample props 🔥
  • single_context — whether we're monitoring a single gpu context or all of them. choose your fighter ✨
  • hold_preemption — whether preemption is disabled for the filtered context. heads up, that's a real behaviour switch, not just a cute name 💀
  • ctx_handle — a gem ctx handle, for use with single_context. they're a package deal 🫶
  • metrics_set — an ID for an OA unit metric set, advertised via sysfs. she's official 👑
  • oa_format — an OA unit HW report format. it's giving "formatting era" 🌈
  • oa_periodic — whether to enable periodic OA unit sampling. tick tock ⭐
  • oa_period_exponent — the OA unit sampling period is derived from this. math queen 🧚
  • engine — the engine being monitored by the OA unit, typically rcs0. main character engine energy 💜
  • has_sseu — whether sseu was specified by userspace. yes/no, that's the whole job 🎀
  • sseu — the internal SSEU configuration, computed either from the userspace-specified configuration in the opening parameters or from a default value (see get_default_sseu_config). two paths, one struct 🌸
  • poll_oa_period — the period in nanoseconds at which the CPU will check for OA data availability. nanoseconds!! she's precise 🦋

💖 Description 💖

so basically — while read_properties_unlocked is out here enumerating and validating all the properties you handed over to open a stream of metrics, the configuration gets built up in this struct. and plot twist: it starts out zero initialized. clean slate, fresh start, new me 💅✨

🔥 SEE ALSO 🔥

the whole friend group, in the order the manual says (and yes, every single one, we don't do skipping here):

bestie reminder: the source path for this whole page is ./drivers/gpu/drm/i915, and it's dated October 2026 — so yeah, this manual page is from the future, we love a time traveler 👑💫

and that's the page!! struct understood, vibes immaculate, struct perf_open_properties(9) ate and left no crumbs 🍓💜

📦 where this page comes from