Re: [PATCH 1/3] epoll: increase default max_user_instances to 1024

Davide Libenzi
2009-01-28T16:53:16Z

On Wed, 28 Jan 2009, Vegard Nossum wrote:

> On Wed, Jan 28, 2009 at 6:32 AM, Bron Gondwana <brong@fastmail.fm> wrote:
> > That's clearly not happening here - so it seems that maybe our "happy
> > medium" is actually in closer inspection of what's going on rather than
> > a blanket low N to keep N^2 down.
>
> Mh, could another solution to this all be to limit the number times
> you can add a single epoll descriptor to another descriptor's set?

In the example that was posted, a single fd was added a single time inside
the other 1000+ fds. Epoll already has detection for too long chains and
closed loops, but you can't put those in the fast path. And epoll_ctl() is
one of those.

- Davide