From: Ingo Molnar <mingo@elte.hu>
To: Peter Williams <peterw@aurema.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [RFC][PATCH][2.6.6] Replacing CPU scheduler active and expired with a single array
Date: Fri, 28 May 2004 11:29:00 +0200 [thread overview]
Message-ID: <20040528092900.GA23347@elte.hu> (raw)
In-Reply-To: <40B70542.2060006@aurema.com>
* Peter Williams <peterw@aurema.com> wrote:
> >just try it - run a task that runs 95% of the time and sleeps 5% of the
> >time, and run a (same prio) task that runs 100% of the time. With the
> >current scheduler the slightly-sleeping task gets 45% of the CPU, the
> >looping one gets 55% of the CPU. With your patch the slightly-sleeping
> >process can easily monopolize 90% of the CPU!
>
> If these two tasks have the same nice value they should around robin
> with each other in the same priority slot and this means that the one
> doing the smaller bites of CPU each time will in fact get less CPU
> than the other i.e. the outcome will be the opposite of what you
> claim.
just try what i described with and without your patch and look at the
'top' output. You can do a simple loop plus short 10-20msec sleeps (via
nanosleep) to simulate a 95% busy task.
Ingo
next prev parent reply other threads:[~2004-05-28 9:28 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-05-28 4:52 [RFC][PATCH][2.6.6] Replacing CPU scheduler active and expired with a single array Peter Williams
2004-05-28 9:05 ` Ingo Molnar
2004-05-28 9:24 ` Peter Williams
2004-05-28 9:29 ` Ingo Molnar [this message]
2004-05-28 9:57 ` Con Kolivas
-- strict thread matches above, loose matches on Subject: below --
2004-05-29 1:39 Peter Williams
2004-05-29 5:27 Peter Williams
2004-05-29 11:17 ` Con Kolivas
2004-05-30 0:19 ` Peter Williams
2004-05-30 12:56 ` Con Kolivas
2004-05-31 0:04 ` Peter Williams
2004-05-30 23:13 ` Con Kolivas
[not found] <214A1-6NK-7@gated-at.bofh.it>
[not found] ` <21acm-2GN-1@gated-at.bofh.it>
2004-05-29 12:24 ` Andi Kleen
2004-05-29 12:38 ` Con Kolivas
2004-06-04 7:40 ` Peter Williams
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