Message-ID: <004601c3209c$f0739700$0305a8c0@arch.sel.sony.com>
From: "Ming Lei" <lei.ming@attbi.com>
To: <linux-kernel@vger.kernel.org>
Cc: "Elladan" <elladan@eskimo.com>, <efault@gmx.de>
References: <200305142020.h4EKK9J01052@relax.cmf.nrl.navy.mil> <20030514205949.GA3945@kroah.com>
Subject: Re: Linux 2.4 scheduler is RTOS-alike?
Date: Thu, 22 May 2003 13:01:30 -0700
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will it be the same behavior If thread A and thread B both have a lot of
printf? Suppose A get first run, does B get run at all?

> this question is regarding linux kernel 2.4.7-2.4.20.
> linux 2.4 kernel does support real time sheduler. If using FIFO real time
> schedule policy, would the case that higher priority thread starve the
lower
> priority thread happen?  Similarly, let's say an example: if I have higher
> prioority thread A and lower priority thread B, thread A is running
without
> any wait or blocking, is there a possiblity that 2.4 scheduler may want to
> switch to thread B? Why?

Yes, FIFO threads that spin will block lower priority threads forever.

Sure, guaranteed if the high prio SCHED_FIFO task doesn't block at all.  If
you have a pure cpu burner, it will starve all lower priority
threads.

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