Re: listen(2) backlog changes in or around Linux 3.1?

[Eric Dumazet <eric.dumazet@gmail.com>]

On Tue, 2012-10-16 at 16:31 -0700, enh wrote:
> boiling things down to a short C++ program, i see that i can reproduce
> the behavior even on 2.6 kernels. if i run this, i see 4 connections
> immediately (3 + 1, as i'd expect)... but then about 10s later i see
> another 2. and every few seconds after that, i see another 2. i've let
> this run until i have hundreds of connect(2) calls that have returned,
> despite my small listen(2) backlog and the fact that i'm not
> accept(2)ing.
> 
> so i guess the only thing that's changed with newer kernels is timing
> (hell, since i only see newer kernels on newer hardware, it might just
> be a hardware thing).
> 
> and clearly i don't understand what the listen(2) backlog means any more.


Hi Elliott

I would say there is a bug (or several !!), and this needs a fix.

I am investigating.

Thanks