From owner-freebsd-threads@FreeBSD.ORG Thu Jan 15 22:38:45 2009 Return-Path: Delivered-To: freebsd-threads@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id AD2511065694 for ; Thu, 15 Jan 2009 22:38:45 +0000 (UTC) (envelope-from deischen@freebsd.org) Received: from mail.netplex.net (mail.netplex.net [204.213.176.10]) by mx1.freebsd.org (Postfix) with ESMTP id 6BCF38FC21 for ; Thu, 15 Jan 2009 22:38:45 +0000 (UTC) (envelope-from deischen@freebsd.org) Received: from sea.ntplx.net (sea.ntplx.net [204.213.176.11]) by mail.netplex.net (8.14.3/8.14.3/NETPLEX) with ESMTP id n0FMchI7028104; Thu, 15 Jan 2009 17:38:43 -0500 (EST) X-Virus-Scanned: by AMaViS and Clam AntiVirus (mail.netplex.net) X-Greylist: Message whitelisted by DRAC access database, not delayed by milter-greylist-4.0 (mail.netplex.net [204.213.176.10]); Thu, 15 Jan 2009 17:38:44 -0500 (EST) Date: Thu, 15 Jan 2009 17:38:43 -0500 (EST) From: Daniel Eischen X-X-Sender: eischen@sea.ntplx.net To: Pramod Srinivasan In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: freebsd-threads@freebsd.org Subject: Re: Priority scheduling in 6.x X-BeenThere: freebsd-threads@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: Daniel Eischen List-Id: Threading on FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 15 Jan 2009 22:38:47 -0000 On Thu, 15 Jan 2009, Pramod Srinivasan wrote: > Hi Daniel > > Thanks for your response. > > On 1/14/09 7:25 PM, "Daniel Eischen" wrote: > >> On Wed, 14 Jan 2009, Pramod Srinivasan wrote: >> >>> Hi, >>> >>> I have 3 threads low, medium and high , and the scheduling policy is set to >>> SCHED_FIFO. The priority of the threads are at 28,29,30 respectively. Looks >>> like on FreeBSD 6.x, the priority of the threads are not honored while >>> scheduling the threads, but the same test on FreeBSD 7.x seems to work fine. >>> Are there known issues with the priority scheduling in FreeBSD 6.x or am I >>> doing something wrong? (I am using libthr) >> >> Are you using libpthread or libthr on 6.3? > > I am using libthr on 6.1, but had similar issues on 6.2 as well. > >> >> If you are using libthr, then you need to be running with >> superuser privileges for SCHED_FIFO to work. I'm not sure >> if this works correctly at all in 6.3. > > I am running the program with super user privileges on 6.1, tried this on > 6.2 as well. Priority scheduling using libthr does not work, unless I am > missing something very basic?. The same program works fine on 7.1, any > ideas? I'm not sure what kernel scheduler you are using (ULE or BSD), but you can try switching it. Other than that, it probably just won't ever work correctly on 6.x. -- DE