BSD syscall#514
svc · unix #514
__channel_set_opt
Sets a per-channel Skywalk option, e.g. wake policy or scheduler class.
Prototype
int __channel_set_opt(int c, uint32_t opt, const void *aoptval, uint32_t optlen);Returns: int
Arguments
| Name | Type | Dir | Description |
|---|---|---|---|
| c | int | - | |
| opt | uint32_t | - | |
| aoptval | const void | - | |
| optlen | uint32_t | - |
Version history
| XNU tag | macOS | # |
|---|---|---|
| xnu-8792.41.9 | macOS 13.0 Ventura | 514 |
| xnu-10002.1.13 | macOS 14.0 Sonoma | 514 |
| xnu-11215.1.10 | macOS 15.0 Sequoia | 514 |
| xnu-11417.101.15 | macOS 15.4 Sequoia | 514 |
| xnu-12377.1.9 | macOS 26.0 Tahoe | 514 |
| xnu-10002.41.9 | — | 514 |
| xnu-10002.61.3 | — | 514 |
| xnu-10002.81.5 | — | 514 |
| xnu-10063.101.15 | — | 514 |
| xnu-10063.121.3 | — | 514 |
| xnu-10063.141.1 | — | 514 |
| xnu-11215.41.3 | — | 514 |
| xnu-11215.61.5 | — | 514 |
| xnu-11215.81.4 | — | 514 |
| xnu-11417.121.6 | — | 514 |
| xnu-11417.140.69 | — | 514 |
| xnu-12377.101.15 | — | 514 |
| xnu-12377.41.6 | — | 514 |
| xnu-12377.61.12 | — | 514 |
| xnu-12377.81.4 | — | 514 |
| xnu-8019.80.24 | — | 514 |
| xnu-8020.101.4 | — | 514 |
| xnu-8020.121.3 | — | 514 |
| xnu-8020.140.41 | — | 514 |
| xnu-8792.61.2 | — | 514 |
| xnu-8792.81.2 | — | 514 |
| xnu-8796.101.5 | — | 514 |
| xnu-8796.121.2 | — | 514 |
| xnu-8796.141.3 | — | 514 |
Notes
Used to dial in QoS hints, enable/disable interrupt moderation, mark a channel as low-power-eligible, or attach a defunct callback. Some options require the channel to be in a quiesced state, returning EBUSY otherwise. The SK_OPT_DEFUNCT_OK option lets a process voluntarily release its rings under memory pressure without losing the channel handle.
Detection
Not visible to ES. Anomalous use is paired with __channel_open by an unexpected caller.
Related APIs
__channel_get_opt__channel_open__channel_syncsetsockopt