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From: "Li, Tong N" <tong.n.li@intel.com>
To: tingy@cs.umass.edu
Cc: Ingo Molnar <mingo@elte.hu>, linux-kernel@vger.kernel.org
Subject: Re: [patch] CFS scheduler, -v8
Date: Wed, 2 May 2007 11:42:20 -0700	[thread overview]
Message-ID: <1178131340.25170.24.camel@tongli.jf.intel.com> (raw)
In-Reply-To: <4637FE0A.7090405@cs.umass.edu>

>   Based on my understanding, adopting something like EEVDF in CFS should 
> not be very difficult given their similarities, although I do not have 
> any idea on how this impacts the load balancing for SMP. Does this worth 
> a try?
> 
>   Sorry for such a long email :-)

Thanks for the excellent explanation. I think EEVDF and many algs alike
assume global ordering of all tasks in the system (based on virtual
time), whereas CFS does so locally on each processor and relies on load
balancing to achieve fairness across processors. It'd achieve strong
fairness locally, but I'm not sure about its global fairness properties
in an MP environment. If ideally the total load weight on each processor
is always the same, then local fairness would imply global fairness, but
this is a bin packing problem and is intractable ...

  tong

  parent reply	other threads:[~2007-05-02 18:42 UTC|newest]

Thread overview: 75+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-05-01 21:22 Ingo Molnar
2007-05-02  2:57 ` Ting Yang
2007-05-02  5:10   ` Willy Tarreau
2007-05-02  5:30   ` William Lee Irwin III
2007-05-02 10:05   ` Bill Huey
2007-05-02 10:27   ` Ingo Molnar
2007-05-02 17:36   ` Srivatsa Vaddagiri
2007-05-02 17:48     ` William Lee Irwin III
2007-05-02 18:15       ` Ingo Molnar
2007-05-02 18:56         ` William Lee Irwin III
2007-05-02 19:12           ` Ingo Molnar
2007-05-02 19:42             ` William Lee Irwin III
2007-05-03  2:48       ` Ting Yang
2007-05-03  3:18       ` Ting Yang
2007-05-03 10:19         ` Bill Huey
2007-05-02 23:41     ` Ting Yang
2007-05-02 18:42   ` Li, Tong N [this message]
2007-05-02 19:10     ` William Lee Irwin III
2007-05-03  3:07     ` Ting Yang
2007-05-03  8:50   ` Ingo Molnar
2007-05-03 14:26     ` Srivatsa Vaddagiri
2007-05-03 15:19       ` Ting Yang
2007-05-03 15:02     ` Ting Yang
2007-05-02  6:37 ` Mike Galbraith
2007-05-02  6:45   ` Ingo Molnar
2007-05-02  8:03   ` Gene Heskett
2007-05-02  8:12     ` Mike Galbraith
2007-05-02  8:48       ` Gene Heskett
2007-05-02  8:13     ` Ingo Molnar
2007-05-02  8:51       ` Gene Heskett
2007-05-02  7:59 ` Mike Galbraith
2007-05-02  8:11   ` Gene Heskett
2007-05-02 10:40   ` Ingo Molnar
2007-05-02  9:08 ` Balbir Singh
2007-05-02 10:05   ` Ingo Molnar
2007-05-02 10:59     ` Balbir Singh
2007-05-02 11:17       ` Ingo Molnar
2007-05-05  8:31         ` Esben Nielsen
2007-05-05 17:44           ` Linus Torvalds
2007-05-06  8:29             ` Ingo Molnar
2007-05-06  8:36               ` Willy Tarreau
2007-05-06  8:52                 ` Ingo Molnar
2007-05-06 17:45               ` Linus Torvalds
2007-05-07 11:30                 ` Esben Nielsen
2007-05-07 15:55                   ` Ingo Molnar
2007-05-07 16:11                   ` Linus Torvalds
2007-05-08  0:35                   ` Peter Williams
2007-05-08  9:05                     ` Esben Nielsen
2007-05-09  0:01                       ` Peter Williams
2007-05-10 13:09                     ` Pavel Machek
2007-05-11 16:50                       ` Linus Torvalds
2007-05-11 19:18                         ` Pavel Machek
2007-05-11 19:37                           ` Willy Tarreau
2007-05-11 20:53                             ` Kevin Bowling
2007-05-07 11:09             ` Esben Nielsen
2007-05-07 16:28               ` Linus Torvalds
2007-05-07 18:39                 ` Johannes Stezenbach
2007-05-07 18:55                   ` Linus Torvalds
2007-05-08  7:34                   ` Esben Nielsen
2007-05-08  9:54                     ` Johannes Stezenbach
2007-05-08 10:27                       ` Esben Nielsen
2007-05-08  5:36                 ` Matt Mackall
2007-05-02 12:58 ` Mark Lord
2007-05-02 12:58 ` Vegard Nossum
2007-05-02 16:41   ` Ingo Molnar
2007-05-03  8:20 Zoltan Boszormenyi
2007-05-03 13:02 ` Ingo Molnar
2007-05-03 13:29   ` Damien Wyart
2007-05-03 14:53     ` Srivatsa Vaddagiri
2007-05-03 15:53       ` William Lee Irwin III
2007-05-03 18:44         ` Li, Tong N
2007-05-03 19:52           ` William Lee Irwin III
2007-05-07 14:22         ` Srivatsa Vaddagiri
2007-05-07 20:54           ` Li, Tong N
2007-05-07  0:04     ` Bill Davidsen

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