WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-users

Re: [Xen-users] SEDF and latency parameter

To: xen-users@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Xen-users] SEDF and latency parameter
From: Andrej Radonic <andrej.radonic@xxxxxxxx>
Date: Tue, 18 Apr 2006 20:31:48 +0200
Delivery-date: Tue, 18 Apr 2006 11:41:42 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <4cc7339069b74b57e0cf1ce9a06cbf65@localhost>
List-help: <mailto:xen-users-request@lists.xensource.com?subject=help>
List-id: Xen user discussion <xen-users.lists.xensource.com>
List-post: <mailto:xen-users@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=unsubscribe>
References: <4cc7339069b74b57e0cf1ce9a06cbf65@localhost>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Thunderbird 1.5 (X11/20051201)
Timo Benk wrote:
Hi,

can someone explain or point me to some doku where the latency parameter
for the SEDF Parameter is explained?

Greetings,
-timo
Hi Timo,

Suse 10. is accompanied by some interesting xen doku stuff. See /usr/share/doc/xen. Here is the supplied documentation on sedf which contains info on the latency parameter which will hopefully helpful to you.

If - and how - it works please let us know (have no experience with this so far)

<quote>
sEDF scheduler
--------------
Author:
  Stephan.Diestelhorst@{cl.cam.ac.uk, inf.tu-dresden.de}
Overview:
 This scheduler provides weighted CPU sharing in an intuitive way and
 uses realtime-algorithms to ensure time guarantees.

Usage:
  -add "sched=sedf" on Xen's boot command-line
  -create domains as usual
-use "xm sched-sedf <dom-id> <period> <slice> <latency-hint> <extra> <weight>"
   Where:
     -period/slice are the normal EDF scheduling parameters in nanosecs
-latency-hint is the scaled period in case the domain is doing heavy I/O
        (unused by the currently compiled version)
     -extra is a flag (0/1), which controls whether the domain can run in
      extra-time
     -weight is mutually exclusive with period/slice and specifies another
      way of setting a domains cpu slice

Examples:
normal EDF (20ms/5ms):
 xm sched-sedf <dom-id> 20000000 5000000 0 0 0

best-effort domains (i.e. non-realtime):
 xm sched-sedf <dom-id> 20000000 0 0 1 0

normal EDF (20ms/5ms) + share of extra-time:
 xm sched-sedf <dom-id> 20000000 5000000 0 1 0

4 domains with weights 2:3:4:2
 xm sched-sedf <d1> 0 0 0 0 2
 xm sched-sedf <d2> 0 0 0 0 3
 xm sched-sedf <d3> 0 0 0 0 4
 xm sched-sedf <d4> 0 0 0 0 2

1 fully-specified (10ms/3ms) domain, 3 other domains share
available rest in 2:7:3 ratio:
 xm sched-sedf <d1> 10000000 3000000 0 0 0
 xm sched-sedf <d2> 0 0 0 0 2
 xm sched-sedf <d3> 0 0 0 0 7
 xm sched-sedf <d4> 0 0 0 0 3
</quote>

Cheers,
Andrej

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users

<Prev in Thread] Current Thread [Next in Thread>