diff options
| author | Pedro Tammela <pctammela@gmail.com> | 2021-04-12 22:24:32 +0300 |
|---|---|---|
| committer | Andrii Nakryiko <andrii@kernel.org> | 2021-04-13 07:28:33 +0300 |
| commit | 5c507329000e282dce91e6c98ee6ffa61a8a5e49 (patch) | |
| tree | cde581c86fcce3f7041a4039161d535497def5eb /tools/include | |
| parent | aadb2bb83ff789de63b48b4edeab7329423a50d3 (diff) | |
| download | linux-5c507329000e282dce91e6c98ee6ffa61a8a5e49.tar.xz | |
libbpf: Clarify flags in ringbuf helpers
In 'bpf_ringbuf_reserve()' we require the flag to '0' at the moment.
For 'bpf_ringbuf_{discard,submit,output}' a flag of '0' might send a
notification to the process if needed.
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210412192434.944343-1-pctammela@mojatatu.com
Diffstat (limited to 'tools/include')
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index e1ee1be7e49b..85c924bc21b1 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -4082,12 +4082,20 @@ union bpf_attr { * of new data availability is sent. * If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification * of new data availability is sent unconditionally. + * If **0** is specified in *flags*, an adaptive notification + * of new data availability is sent. + * + * An adaptive notification is a notification sent whenever the user-space + * process has caught up and consumed all available payloads. In case the user-space + * process is still processing a previous payload, then no notification is needed + * as it will process the newly added payload automatically. * Return * 0 on success, or a negative error in case of failure. * * void *bpf_ringbuf_reserve(void *ringbuf, u64 size, u64 flags) * Description * Reserve *size* bytes of payload in a ring buffer *ringbuf*. + * *flags* must be 0. * Return * Valid pointer with *size* bytes of memory available; NULL, * otherwise. @@ -4099,6 +4107,10 @@ union bpf_attr { * of new data availability is sent. * If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification * of new data availability is sent unconditionally. + * If **0** is specified in *flags*, an adaptive notification + * of new data availability is sent. + * + * See 'bpf_ringbuf_output()' for the definition of adaptive notification. * Return * Nothing. Always succeeds. * @@ -4109,6 +4121,10 @@ union bpf_attr { * of new data availability is sent. * If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification * of new data availability is sent unconditionally. + * If **0** is specified in *flags*, an adaptive notification + * of new data availability is sent. + * + * See 'bpf_ringbuf_output()' for the definition of adaptive notification. * Return * Nothing. Always succeeds. * |