Adding a new scheduling algorithm to Fiasco.OC

Valentin Hauner valentinhauner at gmx.de
Fri Aug 1 16:28:12 CEST 2014


Hi,

On 06/13/2014 10:01 PM, Adam Lackorzynski wrote:
> You should look at the wfq files as those already
> implement an algorithm that is quite close to EDF
I've found out that Weighted Fair Queuing is used for scheduling network
data packets. However, no source I've read through mentions a similarity
to EDF.

I'm not sure what all those parameters in sched_context-wfq.cpp mean.
Quantum and weight seem clear to me, but what's the semantic of qdw
(quantum divided by weight) and dl? Does the latter one stand for deadline?
What sense does it make to add quantum/left attributes to a EDF-simliar
algorithm?

Another problem was arising when I tried to compile Fiasco with my EDF
scheduler:
I've removed the attributes quantum and left from my
sched_context-edf.cpp implementation and got this error:
> context.cpp:1039:49: error: ‘class Sched_context’ has no member named
‘left’
Obviously, Sched_context needs these parameters, but why? They are used
in context.cpp which should be independent of any concrete scheduling
algorithm, shouldn't it? There is no quantum in deadline based algorithms.

Best regards,
Valentin



More information about the l4-hackers mailing list