>> The way I see it, increasing FD_SETSIZE would have a very small space
>> penalty, a small time penalty for fd-set ops (copying 32 bytes rather
>> than 8), but the user/kernel interface costs are small-to-zero unless
>> one explicitly ups the per-process descriptors limit: since
>> sys_select() clips at fd_nfiles.
>very large descriptor sets have severe scaling problems.
>If you have a large, sparse set of descriptors, use poll(2).	
>If you have a large, dense set, you have an interesting interface
>design problem to make this scale well.  see solaris /dev/poll for one
>approach.  I suspect that there's lot of room for more innovation
>here.

	there was a paper presented by Niels Provos, at USENIX/Freenix2000.

itojun