relay_open(9)

💫 relay_open(9) — the Kernel API Manual, bestie edition 💫

okay so you're reading the relay_open(9) page, iconic choice, this is genuinely one of the fun ones. it lives in the Kernel API Manual and it's all about making a brand new relay channel. let's get into it 🎀

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✨ NAME ✨

relay_open — create a new relay channel. that's the whole vibe. new channel, fresh out the box, slay 💅

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🌸 SYNOPSIS 🌸

struct rchan * relay_open (const char *base_filename , struct dentry
*parent , size_t subbuf_size , size_t n_subbufs , const struct
rchan_callbacks *cb , void *private_data );

like, look at her. six arguments, all main character energy 👑

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🦋 ARGUMENTS 🦋

• base_filename — the base name of the files to create. this is the name-y part of the name, iykyk ✨
• parent — the dentry of the parent directory, NULL for the root directory or buffer. pass NULL and she goes to root, no notes 🫶
• subbuf_size — size of sub-buffers. how big each lil sub-buffer is 🍓
• n_subbufs — number of sub-buffers. how many of them there are, literally just a count 💜
• cb — client callback functions. your callbacks, your rules 🌈
• private_data — user-defined data. whatever you want, no questions asked 🙈

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🔥 DESCRIPTION 🔥

so what does it actually do? it returns the channel pointer if successful, NULL otherwise. that's the deal. NULL means nope 😭

it creates a channel buffer for each cpu using the sizes and attributes specified. not me giving every cpu its own lil buffer, generous queen 👑

the created channel buffer files will be named base_filename0...base_filenameN-1. note the naming, bestie — it's 0 through N-1, don't come for me with off-by-one nonsense 💀

file permissions will be S_IRUSR. that's it. that's the permission. read it and weep (or, like, just read it, that's the only thing you can do) 🌸

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⭐ SEE ALSO ⭐

kernel file ./kernel/relay.c — and the whole relay fam, all of them, no cap:

• relay_mmap_prepare_buf(9)
• relay_alloc_buf(9)
• relay_create_buf(9)
• relay_destroy_channel(9)
• relay_destroy_buf(9)
• relay_remove_buf(9)
• relay_buf_empty(9)
• relay_buf_full(9)
• wakeup_readers(9)
• __relay_reset(9)
• relay_reset(9)
• relay_close_buf(9)
• relay_switch_subbuf(9)
• relay_subbufs_consumed(9)
• relay_close(9)
• relay_flush(9)
• relay_stats(9)
• relay_file_open(9)
• relay_file_mmap_prepare(9)
• relay_file_poll(9)
• relay_file_release(9)
• relay_file_read_subbuf_avail(9)
• relay_file_read_start_pos(9)
• relay_file_read_end_pos(9)

go read all of them, or don't, I'm not your mom 🧚

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💖 that's the whole page! go open a relay channel, you've got this!

mwah 💋 this one came straight out of ./kernel and it's dated October 2026, so like, remember that when you cite her. periodt.