> been reading the select(2) man pages and it mentions poll(2)

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> being more efficient in most cases. this makes it obvious to

> discard the use of select(2) in writing new servers.

select requires that you set up a bit array correctly.  but often

people just use a fd_set, and cause a variety of strange buffer

overflow cases as soon as their fd's happen to be greater than the bit

size of the fd_set.
the kernel has to iterate over these bit arrays a few times.
for everyone involved, poll is just plain cheaper.
finally, go look at the latest commit to lib/libc/net/res_send.c to

see how much easier poll() is to use.
> i've come across some performance benchmarks which is trying

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> to use kqueue(2).

shrug.  performance is only a small part of the whole.
> the question is, which one is more useful when writing new servers?

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> kqueue or poll?

use poll.  it is easier to use -- the behaviours are less surprising.

it is also much more portable.  everyone has select and poll, and

quite honestly poll() is a better select(), even if it came out of

AT&T.