From: William Lee Irwin III <wli@holomorphy.com>
To: Daniel Phillips <phillips@arcor.de>
Cc: rob@landley.net, Ed Sweetman <ed.sweetman@wmich.edu>,
Eugene Teo <eugene.teo@eugeneteo.net>,
LKML <linux-kernel@vger.kernel.org>,
kernel@kolivas.org, Davide Libenzi <davidel@xmailserver.org>
Subject: Re: Ingo Molnar and Con Kolivas 2.6 scheduler patches
Date: Thu, 7 Aug 2003 13:45:59 -0700 [thread overview]
Message-ID: <20030807204559.GY32488@holomorphy.com> (raw)
In-Reply-To: <200308071642.55517.phillips@arcor.de>
On Wednesday 06 August 2003 22:28, Rob Landley wrote:
>> So, how does SCHED_SOFTRR fail? Theoretically there is a minimum timeslice
>> you can hand out, yes? And an upper bound on scheduling latency. So
>> logically, there is some maximum number "N" of SCHED_SOFTRR tasks running
>> at once where you wind up round-robining with minimal timeslices and the
>> system is saturated. At N+1, you fall over. (And in reality, there are
>> interrupts and kernel threads and other things going on that get kind of
>> cramped somewhere below N.)
On Thu, Aug 07, 2003 at 04:42:55PM +0100, Daniel Phillips wrote:
> The upper bound for softrr realtime scheduling isn't based on number
> of tasks, it's a global slice of cpu time: so long as the sum of
> running times of all softrr tasks in the system lies below limit,
> softrr tasks will be scheduled as SCHED_RR, otherwise they will be
> SCHED_NORMAL.
You're thinking of Little's law, which is describes the mean number of
waiters on a queue as the mean service time divided by the number of
servers times the mean inter-arrival time.
-- wli
next prev parent reply other threads:[~2003-08-07 20:45 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-07-26 9:30 Ingo Molnar and Con Kolivas 2.6 scheduler patches Felipe Alfaro Solana
2003-07-26 9:46 ` Marc-Christian Petersen
2003-07-26 10:02 ` Ismael Valladolid Torres
2003-07-26 10:10 ` Eugene Teo
2003-07-26 11:24 ` Ed Sweetman
2003-07-26 17:00 ` Rahul Karnik
2003-07-27 15:46 ` Daniel Phillips
2003-07-26 16:52 ` Diego Calleja García
2003-07-26 18:35 ` Andrew Morton
2003-07-26 23:01 ` Diego Calleja García
2003-07-28 9:38 ` Felipe Alfaro Solana
2003-07-28 10:37 ` Måns Rullgård
2003-07-28 17:06 ` Diego Calleja García
2003-07-27 2:38 ` Con Kolivas
2003-07-27 7:39 ` Willy Tarreau
2003-07-27 9:12 ` Ingo Molnar
2003-07-27 11:54 ` Con Kolivas
2003-07-27 20:18 ` Daniel Phillips
2003-07-26 22:05 ` Ed Sweetman
2003-08-01 15:38 ` Daniel Phillips
2003-07-31 23:02 ` Ed Sweetman
2003-07-27 2:39 ` Ed Sweetman
2003-07-29 13:56 ` Timothy Miller
2003-07-29 13:57 ` Con Kolivas
2003-07-29 15:30 ` Timothy Miller
2003-07-29 15:52 ` Helge Hafting
2003-07-29 16:26 ` Timothy Miller
2003-07-30 14:46 ` Daniel Phillips
2003-07-29 15:40 ` Timothy Miller
2003-07-30 16:17 ` Daniel Phillips
2003-08-08 21:09 ` Bill Huey
2003-08-06 21:28 ` Rob Landley
2003-08-07 9:34 ` Helge Hafting
2003-08-07 15:42 ` Daniel Phillips
2003-08-07 20:45 ` William Lee Irwin III [this message]
2003-08-07 20:51 ` Rob Landley
2003-08-07 21:40 ` Ed Sweetman
2003-08-07 22:17 ` William Lee Irwin III
2003-08-08 0:01 ` Rob Landley
2003-08-09 20:52 ` George Anzinger
2003-08-14 0:24 ` Rob Landley
2003-08-14 8:01 ` George Anzinger
2003-08-16 9:10 ` Rob Landley
2003-08-16 14:29 ` APM and 2.5.75 not resuming properly Jamie Lokier
2003-08-16 15:03 ` Stephen Rothwell
2003-08-16 16:12 ` Jamie Lokier
2003-08-16 20:43 ` Rob Landley
2003-08-13 3:38 ` Ingo Molnar and Con Kolivas 2.6 scheduler patches George Anzinger
2003-08-08 6:08 ` Daniel Phillips
2003-07-26 12:08 ` Ismael Valladolid Torres
2003-07-26 14:54 ` Con Kolivas
2003-07-26 14:49 ` Con Kolivas
2003-07-26 14:47 ` Con Kolivas
2003-07-26 16:42 ` Lou Langholtz
2003-07-26 16:40 ` Jens Axboe
2003-07-26 18:19 ` William Lee Irwin III
2003-07-26 18:31 ` Felipe Alfaro Solana
2003-07-26 19:20 ` William Lee Irwin III
2003-07-26 19:47 ` William Lee Irwin III
2003-07-27 9:24 ` Ingo Molnar
2003-07-27 9:57 ` Con Kolivas
2003-07-27 10:02 ` Ingo Molnar
2003-07-27 10:19 ` Con Kolivas
2003-07-28 22:44 ` Timothy Miller
2003-07-26 14:44 Downing, Thomas
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