trace_io_uring_register(9)

💅 trace_io_uring_register — the Kernel API Manual, bestie edition ✨

okay so bestie, we're literally in the Kernel API Manual section today, and the star of the show is trace_io_uring_register. it's a tracepoint, it's iconic, it's giving "i know what you registered last summer" 🎀

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✨ NAME ✨

trace_io_uring_register — called after a buffer/file/eventfd was successfully registered for a ring 🦋

like, after it worked. not before. success only. slay.

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🌸 SYNOPSIS 🌸

void trace_io_uring_register (void *ctx , unsigned opcode , unsigned
nr_files , unsigned nr_bufs , long ret );

that's the whole signature, no cap. five params, zero drama 💅

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🧚 ARGUMENTS 🧚

• ctx — pointer to a ring context structure. it's the ring's whole vibe, okurr 💖
• opcode — describes which operation to perform. tell me what we're doing gurl 🔥
• nr_files — -- undescribed --. yeah. the kernel docs left this one on read 😭 that's genuinely what it says, i'm not gatekeeping anything from you
• nr_bufs — -- undescribed --. also left on read 🙈 same energy, same honesty
• ret — return code. the receipts. how did it go ⭐

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💜 DESCRIPTION 💜

so this tracepoint is the one that lets you trace fixed files/buffers — the ones that could be registered to avoid an overhead of getting references to them for every operation. like, imagine not re-asking for the same reference every single time?? the efficiency. the audacity. we stan 🫶

and here's the tea: this event, together with io_uring_file_get, can provide a full picture of how much overhead one can reduce via fixing. so you pair those two up and suddenly you can literally see the savings. main character data. 📊✨

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👑 SEE ALSO 👑

• Kernel file ./include/trace/events/io_uring.h — go read the source, it's right there bestie
• trace_io_uring_create(9)
• trace_io_uring_file_get(9)
• trace_io_uring_queue_async_work(9)
• trace_io_uring_defer(9)
• trace_io_uring_link(9)
• trace_io_uring_cqring_wait(9)
• trace_io_uring_fail_link(9)
• trace_io_uring_complete(9)
• trace_io_uring_submit_req(9)

the whole squad, fr fr 💀✨

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reminder that nr_files and nr_bufs are literally documented as -- undescribed -- in the original. i'm not hiding lore from you, the lore just doesn't exist 🙈

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and that's the page!! 🎀 it lives over in ./include/trace/events, and this little drop is dated October 2026, in the Kernel API Manual (man section 9, iykyk). mwah, go trace something cute 💖🌈💅