Skip to content

Helper function bpf_ringbuf_query

v5.8

Definition

Copyright (c) 2015 The Libbpf Authors. All rights reserved.

Query various characteristics of provided ring buffer. What exactly is queries is determined by flags:

  • BPF_RB_AVAIL_DATA: Amount of data not yet consumed.
  • BPF_RB_RING_SIZE: The size of ring buffer.
  • BPF_RB_CONS_POS: Consumer position (can wrap around).
  • BPF_RB_PROD_POS: Producer(s) position (can wrap around).

Data returned is just a momentary snapshot of actual values and could be inaccurate, so this facility should be used to power heuristics and for reporting, not to make 100% correct calculation.

Returns

Requested value, or 0, if flags are not recognized.

static __u64 (* const bpf_ringbuf_query)(void *ringbuf, __u64 flags) = (void *) 134;

Usage

Docs could be improved

This part of the docs is incomplete, contributions are very welcome

Program types

This helper call can be used in the following program types:

Example

Docs could be improved

This part of the docs is incomplete, contributions are very welcome