[Click] Re: about ToDevice

[Yihong Zhou]

Eddie :

Thanks for your reply. As I understand, the resolution for click timer is
about 0.01 seconds.  I don't know how often the task scheduling list would
be polled.  Since we need to keep the timing for 802.11 packets processing,
we may need a timer or task scheduler that has the granularity of
microseconds.  Would that be possible in click?  Or we may need to implement
a timer with smaller granularity?

----- Original Message ----- 
From: "Eddie Kohler" <kohler at cs.ucla.edu>
To: "Yihong Zhou" <zyihong at ece.utexas.edu>
Cc: <click at amsterdam.lcs.mit.edu>
Sent: Wednesday, June 23, 2004 1:11 AM
Subject: Re: about ToDevice


> Hi Yihong,
>
> Well, generally speaking, the ToDevice will fall off the "task scheduling
list"w
> when the queue is empty, and go onto the "task scheduling list" when the
queue
> becomes nonempty.  This is assuming that the ToDevice is fed by exactly
one
> Queue.  The "task scheduling list" consists of tasks that are run at a
very high
> frequency, polling-style.
>
> And no, you don't need to patch the kernel to run click user-level.
>
> Eddie
>
>
> Yihong Zhou wrote:
> > Hi, Eddie:
> >
> > I have a simple question:
> >
> > How is "ToDevice" scheduled?  Let's say, it pulls packets from the queue
> > so that the click can control the timing of packet processing. ToDevice
> > is derived from AnyTaskDevice, and there is _Task private data member.
> > Is it scheduled periodically, or is it triggered by some other events?
> >
> > By the way, if we want to run click in the user level, do we need to
> > patch the linux kernel?
> >
> > Thanks a lot.
> >
> >
>