From owner-freebsd-hackers Wed May 13 13:46:11 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id NAA13588 for freebsd-hackers-outgoing; Wed, 13 May 1998 13:46:11 -0700 (PDT) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from hda.hda.com (hda-bicnet.bicnet.net [208.220.66.37]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id NAA13452 for ; Wed, 13 May 1998 13:45:58 -0700 (PDT) (envelope-from dufault@hda.hda.com) Received: (from dufault@localhost) by hda.hda.com (8.8.5/8.8.5) id QAA28520; Wed, 13 May 1998 16:41:00 -0400 (EDT) From: Peter Dufault Message-Id: <199805132041.QAA28520@hda.hda.com> Subject: Re: sched_setscheduler() usage? In-Reply-To: <199805131841.UAA10458@zibbi.mikom.csir.co.za> from John Hay at "May 13, 98 08:41:28 pm" To: jhay@mikom.csir.co.za (John Hay) Date: Wed, 13 May 1998 16:41:00 -0400 (EDT) Cc: hackers@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL25 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG The real time priorities SCHED_FIFO and SCHED_RR are in the class of the RTPRIO priorities and should be treated identically. They share the same scheduling code. SCHED_FIFO processes don't round robin across same level priorities while SCHED_RR do. We have a three level scheme: 1. Idle priority; 2. Normal time sharing; 3. rtprio / SCHED_FIFO / SCHED_RR. Your sample should indeed preempt normal timesharing processes. If this isn't working contact me offline and I'll send you some regression tests to see if it has broken, or if I'm broken. I don't explicitly have a test that verifies that the minimum SCHED_FIFO scheduler works. I assume you have configured in the scheduler stuff? > Another question, where does the sched_setscheduler() priorities fit > in with the rest of our priorities? I have started to look through > the kernel code, but because I don't know what its relationship to > the rest of the priorities should be, it is difficult to figure out > where the problem is. I'll check the man page and clarify this. I've had to give up my crash box for a while so I can't check this. Peter -- Peter Dufault (dufault@hda.com) Realtime development, Machine control, HD Associates, Inc. Safety critical systems, Agency approval To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message