Re: [PATCH] async poll for 2.5

[Shailabh Nagar <nagar@watson.ibm.com>]

Dan Kegel wrote:

>Benjamin LaHaise wrote:
>
>>On Mon, Oct 14, 2002 at 06:36:45PM -0400, Shailabh Nagar wrote:
>>
>>>As of today, there is no scalable alternative to poll/select in the 2.5
>>>kernel even though the topic has been discussed a number of times
>>>before. The case for a scalable poll has been made often so I won't
>>>get into that.
>>>
>>Have you bothered addressing the fact that async poll scales worse than
>>/dev/epoll?  That was the original reason for dropping it.
>>
>
>Doesn't the F_SETSIG/F_SETOWN/SIGIO stuff qualify as a scalable
>alternative?
>It's in 2.5 as far as I know.   It does suffer from using the signal
>queue,
>but it's in production use on servers that handle many thousands of 
>concurrent connections, so it's pretty scalable.
>
>- Dan
>

Dan,

Are there any performance numbers for F_SETSIG/F_SETOWN/SIGIO on 2.5 ? 
Does it scale with the number of active connections too ?

Signal-per-fd seems to be a decent alternative (from the measurements on 
Davide's /dev/epoll page) but Vitaly Luban's patch for that isn't available
for 2.5 so I'm not sure what other issues it might have.

-- Shailabh