EF_UL_EPOLL

Name

ul_epoll

Default

1

Minimum

0

Maximum

3

Scope

per-process

Choose epoll implementation. The choices are:

• 0 - kernel (unaccelerated)
• 1 - user-level (accelerated, lowest latency)
• 2 - kernel-accelerated (best when there are lots of sockets in the set and mode 3 is not suitable)
• 3 - user-level (accelerated, lowest latency, scalable, supports socket caching).

The default is the user-level implementation (1).

Mode 3 can offer benefits over mode 1, particularly with larger sets. However, this mode has some restrictions:

• It does not support epoll sets that exist across fork().
• It does not support monitoring the readiness of the set's epoll fd via a another epoll/poll/select.