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Date: Wed, 4 Aug 2004 19:00:41 -0700
From: William Lee Irwin III <wli@holomorphy.com>
To: Peter Williams <pwil3058@bigpond.net.au>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
       Michal Kaczmarski <fallow@op.pl>, Shane Shrybman <shrybman@aei.ca>
Subject: Re: [PATCH] V-3.0 Single Priority Array O(1) CPU Scheduler Evaluation
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William Lee Irwin III wrote:
>> Software constructs are less of a concern. This also presumes that
>> taking timer interrupts when cpu-intensive workloads voluntarily
>> yield often enough is necessary or desirable.

On Thu, Aug 05, 2004 at 11:06:51AM +1000, Peter Williams wrote:
> Voluntary yielding can't be relied upon.  Writing a program that never 
> gives up the CPU voluntarily is trivial.  Some have been known to do it 
> without even trying :-)

No reliance is implied. In such a scenario, the timers for timeslice
expiry are always cancelled because userspace voluntarily yields first,
so no timer interrupts are delivered. Should userspace fail to do so,
timer interrupts programmed for timeslice expiry would not be cancelled.


-- wli