/dev/poll provides a highly scalable way of polling a large number of file descriptors. This is provided through a new set of APIs and a new driver, /dev/poll. The /dev/poll API is an alternative to, not a replacement of poll(2). poll(7D) provides details and examples of the /dev/poll API. When used properly, the /dev/poll API scales much better than poll(2). It is especially suited for applications that satisfy the following criteria:
Applications repeatedly poll a large number of file descriptors.
The polled file descriptors are relatively stable, that is they are not constantly closed and reopened.
The set of file descriptors which actually have polled events pending is small, comparing to the total number of file descriptors being polled.