From owner-freebsd-questions@FreeBSD.ORG Mon Feb 14 09:49:06 2005 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id BD7A516A4DF for ; Mon, 14 Feb 2005 09:49:06 +0000 (GMT) Received: from demas002.adtranz.com (demas002.adtranz.com [213.68.98.31]) by mx1.FreeBSD.org (Postfix) with ESMTP id A30AD43D46 for ; Mon, 14 Feb 2005 09:49:05 +0000 (GMT) (envelope-from mats.lindberg@se.transport.bombardier.com) Received: from EMEAML02.UK.BOMBARDIER.TRANSPORT.COM (emea-ml02 [10.157.248.22]) by demas002.adtranz.com (8.12.9/8.12.9) with ESMTP id j1E9jX3X020332 for ; Mon, 14 Feb 2005 10:45:33 +0100 (MET) To: freebsd-questions@freebsd.org MIME-Version: 1.0 X-Mailer: Lotus Notes Release 6.0 September 26, 2002 From: mats.lindberg@se.transport.bombardier.com Message-ID: Date: Mon, 14 Feb 2005 10:51:13 +0100 X-MIMETrack: Serialize by Router on EMEA-ML02/Server/Transport/Bombardier(Release 6.0.3|September 18, 2003) at 02/14/2005 09:51:13, Serialize complete at 02/14/2005 09:51:13 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.1 Subject: Kernel preemption X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 14 Feb 2005 09:49:06 -0000 Hello, I'm interested in using freebsd in a 'not so realtime, but...' software=20 project. In our running environment there are a 3 processes that need high=20 priority. The processes never need much cpu but they should be able to respond to=20 network (tcp) activity within 10-20ms. I have a testprogram in C that sends ~24kB tcp-messages via a switched=20 ethernet. Sometimes there is a ~250ms delay in receiving (or sending). This could=20 happen after an hour or so. I've tried building a 5.3 system with PREEMPTION and the 4BSD Scheduler.=20 It did not help. I've tried building a 6.0 current system with PREEMPTION and the ULE=20 scheduler. It did not boot. I've tried this on a linux preemptive kernel and it works fine. Is the PREEMPTION option applicable for my problem? Should PREEMPTION work for the 4BSD scheduler? Mats =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=20 This e-mail communication (and any attachment/s) may contain confidential=20 or privileged information and is intended only for the individual(s) or=20 entity named above and to others who have been specifically authorized to=20 receive it. If you are not the intended recipient, please do not read,=20 copy, use or disclose the contents of this communication to others. Please = notify the sender that you have received this e-mail in error by reply=20 e-mail, and delete the e-mail subsequently.=20 Thank you.=20 =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=20 Ce message (ainsi que le(s) fichier/s), transmis par courriel, peut=20 contenir des renseignements confidentiels ou prot=E9g=E9s et est destin=E9 = =E0=20 l?usage exclusif du destinataire ci-dessus. Toute autre personne est par=20 les pr=E9sentes avis=E9e qu?il est strictement interdit de le diffuser, le = distribuer ou le reproduire. Si vous l?avez re=E7u par inadvertance,=20 veuillez nous en aviser et d=E9truire ce message.=20 Merci.=20 =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=20 =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=20 This e-mail communication (and any attachment/s) may contain confidential=20 or privileged information and is intended only for the individual(s) or=20 entity named above and to others who have been specifically authorized to=20 receive it. If you are not the intended recipient, please do not read,=20 copy, use or disclose the contents of this communication to others. Please = notify the sender that you have received this e-mail in error by reply=20 e-mail, and delete the e-mail subsequently.=20 Thank you.=20 =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=20 Ce message (ainsi que le(s) fichier/s), transmis par courriel, peut=20 contenir des renseignements confidentiels ou prot=E9g=E9s et est destin=E9 = =E0=20 l?usage exclusif du destinataire ci-dessus. Toute autre personne est par=20 les pr=E9sentes avis=E9e qu?il est strictement interdit de le diffuser, le = distribuer ou le reproduire. Si vous l?avez re=E7u par inadvertance,=20 veuillez nous en aviser et d=E9truire ce message.=20 Merci.=20 =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=20