- Name
-
so_busy_poll_spin - Default
-
0 - Minimum
-
0 - Maximum
-
1 - Scope
- per-process
Spin poll, select and epoll in a Linux-like way: enable spinning only if a spinning socket is preset in the poll/select/epoll set. See Linux documentation on SO_BUSY_POLL socket option for details.
You should also enable spinning via EF_{POLL, SELECT, EPOLL}_SPIN variable if you'd like to spin in poll, select or epoll correspondingly. The spin duration is set via EF_SPIN_USEC, which is equivalent to the Linux sysctl.net.busy_poll value. EF_POLL_USEC is all-in-one variable to set for all 4 variables mentioned here.
Most versions of Linux never spin in epoll, but Onload does. This variable does not affect epoll behavior if EF_UL_EPOLL=2.