Subject: Re: device polling system
To: Takahiro Igarashi <thir@thir.org>
From: Simon Burge <simonb@wasabisystems.com>
List: tech-kern
Date: 05/29/2003 02:29:57
Takahiro Igarashi wrote:

> I am now working to implement the device polling system on
> NetBSD.  The project page is at:
> 
> http://thir.org/thir/NetBSD/devicepolling.en.html
> 
> The patch is still based on FreeBSD's one.  But I now start
> to select the way of implementation of it and so on.
> Fortunately my patch seems to work well.
> 
> Comments?

From a quick glance at the diff:

+#define        IFF_DEBUG       0x00004         /* turn on debugging */
+#define        IFF_POLLING     0x00004         /* interface is in polling mode */ 

These flags have the same value.


I seem to recall some OS that switches to polled devices when it gets to
a certain busy threshhold.  Can you switch between interrupt-driven and
polling on the fly, or is an all or nothing decision?  Anyone know the
OS(s) that does this, and how well it works?

Simon.
--
Simon Burge                            <simonb@wasabisystems.com>
NetBSD Support and Service:         http://www.wasabisystems.com/