Re: kqueue: SIGIO?

[Tobias Nygren <tnn%NetBSD.org@localhost>]

On Tue, 29 Sep 2015 12:56:36 +0200
Joerg Sonnenberger <joerg%britannica.bec.de@localhost> wrote:

> On Tue, Sep 29, 2015 at 11:31:20AM +0200, Thomas Klausner wrote:

> > During the XDC last week, Keith Packard talked about a select(2) issue
> > in xserver he would like to fix with epoll and its support for SIGIO.
> > Is there a similar feature in kqueue in NetBSD?
> 
> It would be easier to answer that question if we know what issue he was
> actually talking about.

From my (limited) understanding it is about preventing starvation of
other X clients when one client is hammering the server with requests.

When they are processing events for one client in a tight loop they
don't want to periodically check if other clients are ready for I/O,
but would instead like to get notified via a signal.

Here is the relevant bit of the talk if you are curious:

https://www.youtube.com/watch?v=t400SmZlnO8&feature=youtu.be&t=1888