prb_first_valid_seq(9)

💖 prb_first_valid_seq — a.k.a. "bestie, where does the printk ringbuffer even START" 💖

okay so real talk, this is a page from the Kernel API Manual, section 9, and it's all about the function prb_first_valid_seq, bestie. it does exactly one thing and it does it iconically: gets u the sequence number of the oldest available record. that's it. that's the whole vibe. 🎀

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✨ SYNOPSIS ✨

u64 prb_first_valid_seq (struct printk_ringbuffer *rb );

like, u hand it a ringbuffer and it hands u back a u64. simple. clean. no cap. 💅

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🫶 ARGUMENTS 🫶

• rb — the ringbuffer u want the sequence number from. that's the whole argument. just the one. she's low maintenance like that ✨

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🌸 DESCRIPTION 🌸

so this is the public function, right — the one that's actually out there for readers to use — and what it does is tell u what the first/oldest valid sequence number is. like, "hey bestie, this is where the good stuff starts." 👑

and that's literally the point: it gives readers a starting point to begin iterating the ringbuffer. u can't just vibe ur way through a ringbuffer from nowhere, u need an entry point, and this function is that entry point. it's giving main character energy for the whole iteration loop, honestly. 🔥

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🦋 CONTEXT 🦋

Any context. that's it. any. context. call it wherever, she's not picky. 💀✨

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🌈 RETURN 🌈

• the sequence number of the first/oldest record — iconic, perfect, exactly what u asked for 💖
• or, if the ringbuffer is empty, 0 is returned. yeah. zero. nada. the ringbuffer said "no thoughts, head empty" and u get a 0 for it 😭

so like, heads up: 0 means empty here, not "record number zero". check urself before u wreck urself 🫶

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👑 SEE ALSO 👑

• Kernel file ./kernel/printk/printk_ringbuffer.c
• printk_ringbuffer overview(9)
• prb_reserve_in_last(9)
• prb_reserve(9)
• prb_commit(9)
• prb_final_commit(9)
• prb_next_reserve_seq(9)
• prb_read_valid(9)
• prb_read_valid_info(9)
• prb_next_seq(9)
• prb_init(9)
• prb_record_text_space(9)

like genuinely go read printk_ringbuffer overview(9) first if ur lost, it's the syllabus for this whole class fr fr 📚💜

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and that's the page!! mwah 💋 this one came out of ./kernel/printk, dated October 2026, and it lives at prb_first_valid_seq(9) — go forth and iterate responsibly, bestie 🌟🍓🧚