Re: [patch] CFS scheduler, -v14

From: Li Yu
Date: Tue Jun 05 2007 - 04:55:11 EST


Ingo Molnar wrote:
* Li Yu <raise.sail@xxxxxxxxx> wrote:

Eh, I wrong again~ I even took an experiment in last week end, this idea is really bad! ;(

I think the most inner of source of my wrong again and again is misunderstanding virtual time. For more better understanding this, I try to write one python script to simulate CFS behavior. However, It can not implement the fairness as I want. I really confuse here.

Would you like help me point out what's wrong in it? Any suggestion is welcome. Thanks in advanced.

sorry, my python-fu is really, really weak. All i can give you at the moment is the in-kernel implementation of CFS :-)

:~)

I changed that script to check my understanding of virtual clock. I found out we really got the really fairness if allocate resource by selecting the most earliest task virtual clock! this really eliminate my doubt on virtual clock in much degree. for example:

./htucfs.py 60

==============================
TASK_1/C10.00 / 1.0 : 11.0 sec
TASK_2/C10.00 / 2.0 : 20.0 sec
TASK_3/C10.00 / 3.0 : 30.0 sec
==============================

It seem my haltingly english works fine when I read the introduction of virtual clock ;-)

The next step is find out why wait_runtime can not work normally in my script.

Thanks for your quickly reply.

Good luck.

- Li Yu
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