EF_POLL_USEC - EF_POLL_USEC - UG1586

Name

ef_poll_usec_meta_option

Default

0

Scope

per-process

This option enables spinning and sets the spin timeout in microseconds.

Setting this option is equivalent to: Setting EF_SPIN_USEC and EF_BUZZ_USEC, enabling spinning for UDP sends and receives, TCP sends and receives, select, poll and epoll_wait(), and enabling lock buzzing.

Spinning typically reduces latency and jitter substantially, and can also improve throughput. However, in some applications spinning can harm performance, particularly application that have many threads. When spinning is enabled you should normally dedicate a CPU core to each thread that spins.

You can use the EF_*_SPIN options to selectively enable or disable spinning for each API and transport. You can also use the onload_thread_set_spin() extension API to control spinning on a per-thread and per-API basis.

See also EF_POLL_USEC.