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-devel

Re: [Xen-devel] atropos scheduler broken

To: mark.williamson@xxxxxxxxxxxx
Subject: Re: [Xen-devel] atropos scheduler broken
From: Diwaker Gupta <diwakergupta@xxxxxxxxx>
Date: Tue, 26 Oct 2004 11:10:13 -0700
Cc: xen-devel@xxxxxxxxxxxxxxxxxxxxx, Steven Hand <steven.hand@xxxxxxxxxxxx>
Delivery-date: Tue, 26 Oct 2004 19:10:25 +0100
Domainkey-signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:reply-to:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:references; b=OumdeXVkjuNKCOkCZPerpkcWoFHuBRUD4xHoS6ekIMcQ1Ijrcsak7XhSSaza7F8EgHi81nUe5qMjed6/5G7YkKvEmIRvzKAzNvs+W9XJ4EUNQVYrUbiXO0J9K5m7lthgnjOlbDhEnmjyF9+2fjuyuqmgIioxiKDygIrs2XCp2rY=
Envelope-to: steven.hand@xxxxxxxxxxxx
In-reply-to: <200410261645.41209.mark.williamson@xxxxxxxxxxxx>
References: <E1CMLsw-00083A-00@xxxxxxxxxxxxxxxxx> <200410261645.41209.mark.williamson@xxxxxxxxxxxx>
Reply-to: Diwaker Gupta <diwakergupta@xxxxxxxxx>
Hi everyone,

Thats for the replies. Here's the update:

I used Ian's slurp program, with the params suggested by Steven.
Actually I had myself been thinking about the small values that I had
been using, but I was not sure what kind of impact they would have.

Here are the params I used (kind of an extreme case, but I just wanted
to be sure that if there was *some* change, I would be able to see
it):
xm atropos 1 10000    200000 50000 0
xm atropos 2 150000 200000 50000 0

So with these changes, here's a snippet of slurp's output from both
the VMs (VM2 is started a few seconds after VM1)

VM1:
CPU speed = 498 MHz
Slurped 90.72% CPU, TSC 6f70c573
Slurped 97.76% CPU, TSC 8d20a825
Slurped 98.77% CPU, TSC aacff8d9
Slurped 99.14% CPU, TSC c87f42c0
Slurped 99.36% CPU, TSC e62ef069
Slurped 98.22% CPU, TSC 03ded2ca
Slurped 98.71% CPU, TSC 218de63c
Slurped 76.88% CPU, TSC 3f40d8a3
Slurped 46.75% CPU, TSC 5cf03633
Slurped 39.86% CPU, TSC 7ab377bc
Slurped 47.18% CPU, TSC 986e75c5
Slurped 59.25% CPU, TSC b61ddba2
Slurped 51.54% CPU, TSC d3ccf714

VM2:
Slurped 53.26% CPU, TSC 52e34564
Slurped 55.14% CPU, TSC 70ae5af6
Slurped 57.19% CPU, TSC 8e5d809e
Slurped 42.62% CPU, TSC ac0cbb65
Slurped 42.80% CPU, TSC c9bc96d9
Slurped 56.01% CPU, TSC e7766b1c
Slurped 54.60% CPU, TSC 0530e391
Slurped 57.15% CPU, TSC 22e0003b
Slurped 56.18% CPU, TSC 40a1e234
Slurped 57.09% CPU, TSC 5e50c733
Slurped 56.75% CPU, TSC 7c125064
Slurped 55.62% CPU, TSC 99c1f384
Slurped 59.20% CPU, TSC b77143db
Slurped 47.35% CPU, TSC d5365862
Slurped 37.21% CPU, TSC f2e61a4e
Slurped 54.03% CPU, TSC 1095a58f
Slurped 59.79% CPU, TSC 2e675a34

Observations:
o When VM2 is not running, VM1 effectively gets *all* the CPU, even if
the xtratime bit is set to 0.
o When VM2 starts running, it looks like they get roughly equal CPU.
There doesn't seem to be any 'atropos' scheduling happening.

So how should one go about debugging Xen?
-- 
Diwaker Gupta
http://resolute.ucsd.edu/diwaker

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