Poll, ppoll

Onload User Guide (UG1586)

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1.2 English

The poll(), ppoll() file descriptor set can consist of both accelerated and non-accelerated file descriptors. The environment variable EF_UL_POLL enables/disables acceleration of the poll(), ppoll() function calls. Onload supports the following options for the EF_UL_POLL variable:

Table 1. Options for the EF_UL_POLL Variable
Value Behavior

Disable acceleration at user-level. Calls to poll(), ppoll() are handled by the kernel.

Spinning cannot be enabled.


Enable acceleration at user-level. Calls to poll(), ppoll() are processed at user level.

Spinning can be enabled and interrupts are avoided until an application blocks.

Additional environment variables can be employed to control the poll(), ppoll() functions and to give priority to accelerated sockets over non-accelerated sockets and other file descriptors. Refer to EF_POLL_FAST, EF_POLL_FAST_USEC and EF_POLL_SPIN.