From owner-freebsd-current Wed Apr 8 11:28:46 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id LAA26364 for freebsd-current-outgoing; Wed, 8 Apr 1998 11:28:46 -0700 (PDT) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from dyson.iquest.net (dyson.iquest.net [198.70.144.127]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id LAA26350 for ; Wed, 8 Apr 1998 11:28:33 -0700 (PDT) (envelope-from toor@dyson.iquest.net) Received: (from root@localhost) by dyson.iquest.net (8.8.8/8.8.8) id NAA07514; Wed, 8 Apr 1998 13:28:11 -0500 (EST) (envelope-from toor) From: "John S. Dyson" Message-Id: <199804081828.NAA07514@dyson.iquest.net> Subject: Re: kernel support for memory semaphores/locks... In-Reply-To: <199804081412.KAA02721@hda.hda.com> from Peter Dufault at "Apr 8, 98 10:12:52 am" To: dufault@hda.com (Peter Dufault) Date: Wed, 8 Apr 1998 13:28:11 -0500 (EST) Cc: gurney_j@resnet.uoregon.edu, current@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL38 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > > > > thanks, I've done it this way... and leached most of the source from > > sys/i386/i386/simplelock.s... also, I decided to back port the yield > > syscall (note, we now have sched_yield and yield syscalls) to 2.2.1-R > > and it works great... > > Yield sinks you to the bottom of the priorities, which is wrong for > the fixed priority flavor schedulers, and may be more aggressive > than you want. If someone writes a man page for this they should > document this behavior. > > (IMHO) This should be moved to kern_synch since it modifies the priority. > It only modifies the priority temporarily. Our priority scheme is really silly anyway (with the action of tsleep on the priority scheme.) When the process is waken up, the priority is really odd (temporarily high, but long-term correct.) > > Was this added for compatability with another system? > It was added to support some threads work. John To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message