Subject: Re: Hard realtime scheduling
To: Jonathan Stone <>
From: Eduardo Horvath <>
List: tech-kern
Date: 04/05/2005 16:04:47
On Mon, Apr 04, 2005 at 01:06:32PM -0700, Jonathan Stone wrote:

> An illustrative point: Solaris. if memory serves, when Solaris added
> real-time scheduler hooks, one of the changes made was going through
> the kernel source, manually identifying all "long-running" codepaths.
> Checks were inserted into each such path, to check for nearly-overdue
> real-time tasks, and go switch to the real-time task if required.

No, I believe that was the original SVR4.  Sunos 5.x was always
fully preemptive, although it simulated older behavior on timeshare
processes through scheduler magic.