ring_buffer_lock_reserve(9)

Hey bestie!! 💖 You're looking at ring_buffer_lock_reserve(9), straight out of the Kernel API Manual ✨ This is the page that explains how to reserve a little chunk of the ring buffer, and I promise it's less scary than it sounds 🫶

💖 NAME 💖

ring_buffer_lock_reserve — reserve a part of the buffer 👑

✨ SYNOPSIS ✨

struct ring_buffer_event * ring_buffer_lock_reserve (struct trace_buffer
*buffer , unsigned long length );

🎀 ARGUMENTS 🎀

• buffer — the ring buffer you're reserving from, bestie 🌀
• length — the length of the data you wanna reserve, and just so we're clear this is excluding the event header 💅

🦋 DESCRIPTION 🦋

Okay so this returns a reserved event on the ring buffer that you can copy directly to 🎯 The user of this interface will need to get the body to write into, and can use the ring_buffer_event_data interface for that — that's the whole vibe 💖

The length is the length of the data you need, not the event length — the event length also includes the event header, okay?? 😭 Don't mix them up.

Must be paired with ring_buffer_unlock_commit, unless NULL is returned 🫶 If NULL comes back, then nothing has been allocated or locked — like, literally nothing happened. No cap 💀

🌸 SEE ALSO 🌸

Kernel file ./kernel/trace/ring_buffer.c — and the whole friend group is here:

ring_buffer_event_length(9), ring_buffer_event_data(9), rb_page_capacity(9), rb_subbuf_capacity(9), rb_subbuf_max_data_size(9), rb_subbuf_start(9), ring_buffer_event_time_stamp(9), ring_buffer_nr_dirty_pages(9), ring_buffer_wake_waiters(9), ring_buffer_wait(9), ring_buffer_poll_wait(9), rb_check_pages(9), rb_validate_buffer(9), __ring_buffer_alloc(9), __ring_buffer_alloc_range(9), __ring_buffer_alloc_remote(9), ring_buffer_free(9), ring_buffer_resize(9), rb_update_event(9), ring_buffer_nest_start(9), ring_buffer_nest_end(9), ring_buffer_unlock_commit(9), ring_buffer_discard_commit(9), ring_buffer_write(9), ring_buffer_record_disable(9), ring_buffer_record_enable(9), ring_buffer_record_off(9), ring_buffer_record_on(9), ring_buffer_record_is_on(9), ring_buffer_record_is_set_on(9), ring_buffer_record_is_on_cpu(9), ring_buffer_record_disable_cpu(9), ring_buffer_record_enable_cpu(9), ring_buffer_oldest_event_ts(9), ring_buffer_bytes_cpu(9), ring_buffer_entries_cpu(9), ring_buffer_overrun_cpu(9), ring_buffer_commit_overrun_cpu(9), ring_buffer_dropped_events_cpu(9), ring_buffer_read_events_cpu(9), ring_buffer_entries(9), ring_buffer_overruns(9), ring_buffer_iter_reset(9), ring_buffer_iter_empty(9), ring_buffer_peek(9), ring_buffer_iter_peek(9), ring_buffer_consume(9), ring_buffer_read_start(9), ring_buffer_read_finish(9), ring_buffer_iter_advance(9), ring_buffer_size(9), ring_buffer_max_event_size(9), ring_buffer_reset_cpu(9), ring_buffer_reset_online_cpus(9), ring_buffer_reset(9), ring_buffer_empty(9), ring_buffer_empty_cpu(9), ring_buffer_swap_cpu(9), ring_buffer_alloc_read_page(9), ring_buffer_free_read_page(9), ring_buffer_read_page(9), ring_buffer_read_page_data(9), ring_buffer_read_page_size(9), ring_buffer_subbuf_size_get(9), ring_buffer_subbuf_order_get(9), ring_buffer_subbuf_order_set(9)

Byeee bestie 🫶 — this was ring_buffer_lock_reserve(9) from the Kernel API Manual, footer source ./kernel/trace, dated October 2026 🌈💜