i915_oa_wait_unlocked(9)

💖 NAME 💖

hey bestie, welcome to i915_oa_wait_unlocked(9) — your fave page from the Kernel API Manual 👑 and yes, i915_oa_wait_unlocked handles blocking IO until OA data is available. no cap. 💅

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✨ SYNOPSIS ✨

int i915_oa_wait_unlocked (struct i915_perf_stream *stream );

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🌸 ARGUMENTS 🌸

• stream — an i915-perf stream opened for OA metrics. this is the stream bestie we’re waiting on 🫶

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🦋 DESCRIPTION 🦋

okay so picture this: userspace tries to read from a blocking stream FD opened for OA metrics, and this function is the one handling the waiting game 💅 it waits until the hrtimer callback finds a non-empty OA buffer and wakes us up. that’s the whole vibe. ✨

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🎀 NOTE 🎀

ngl, it’s acceptable to have this return with some false positives since any subsequent read handling will return -EAGAIN if there isn’t really data ready for userspace yet. so yeah, a little false-positive moment is not the end of the world 🫶

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⭐ RETURN ⭐

zero on success, or a negative error code. periodt. 💖

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🔥 SEE ALSO 🔥

• Kernel file ./drivers/gpu/drm/i915/i915_perf.c
• i915 Perf Overview(9)
• i915 Perf History and Comparison with Core Perf(9)
• OA Tail Pointer Race(9)
• struct perf_open_properties(9)
• oa_buffer_check_unlocked(9)
• append_oa_status(9)
• append_oa_sample(9)
• gen8_append_oa_reports(9)
• gen8_oa_read(9)
• gen7_append_oa_reports(9)
• gen7_oa_read(9)
• i915_oa_poll_wait(9)
• i915_oa_read(9)
• oa_get_render_ctx_id(9)
• oa_put_render_ctx_id(9)
• i915_oa_stream_enable(9)
• i915_oa_stream_disable(9)
• i915_oa_stream_init(9)
• i915_perf_read(9)
• i915_perf_poll_locked(9)
• i915_perf_poll(9)
• i915_perf_enable_locked(9)
• i915_perf_disable_locked(9)
• i915_perf_ioctl_locked(9)
• i915_perf_ioctl(9)
• i915_perf_destroy_locked(9)
• i915_perf_release(9)
• i915_perf_open_ioctl_locked(9)
• read_properties_unlocked(9)
• i915_perf_open_ioctl(9)
• i915_perf_register(9)
• i915_perf_unregister(9)
• i915_perf_add_config_ioctl(9)
• i915_perf_remove_config_ioctl(9)
• i915_perf_init(9)
• i915_perf_fini(9)
• i915_perf_ioctl_version(9)

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source/version: ./drivers/gpu/drm/i915 🌈 • date: October 2026 🎀 • page: i915_oa_wait_unlocked(9) 💖