From owner-freebsd-current@FreeBSD.ORG Wed Jan 23 18:32:31 2008 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 382A616A418; Wed, 23 Jan 2008 18:32:31 +0000 (UTC) (envelope-from yar@comp.chem.msu.su) Received: from comp.chem.msu.su (comp.chem.msu.su [158.250.32.97]) by mx1.freebsd.org (Postfix) with ESMTP id 9F33613C442; Wed, 23 Jan 2008 18:32:30 +0000 (UTC) (envelope-from yar@comp.chem.msu.su) Received: from comp.chem.msu.su (localhost [127.0.0.1]) by comp.chem.msu.su (8.13.4/8.13.4) with ESMTP id m0NIWIaL056657; Wed, 23 Jan 2008 21:32:18 +0300 (MSK) (envelope-from yar@comp.chem.msu.su) Received: (from yar@localhost) by comp.chem.msu.su (8.13.4/8.13.4/Submit) id m0NIWHwg056656; Wed, 23 Jan 2008 21:32:17 +0300 (MSK) (envelope-from yar) Date: Wed, 23 Jan 2008 21:32:17 +0300 From: Yar Tikhiy To: Astrodog Message-ID: <20080123183217.GK30249@comp.chem.msu.su> References: <20071120141403.GE81260@comp.chem.msu.su> <4743342A.10507@FreeBSD.org> <20080101185451.S957@desktop> <20080121122402.GA63088@comp.chem.msu.su> <2fd864e0801210753y3fc49cd5v67ca75e0376bdb21@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2fd864e0801210753y3fc49cd5v67ca75e0376bdb21@mail.gmail.com> User-Agent: Mutt/1.5.9i Cc: Jeff Roberson , freebsd-current@freebsd.org Subject: Re: SCHED_ULE & niceness / rtprio X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 23 Jan 2008 18:32:31 -0000 On Mon, Jan 21, 2008 at 11:53:49PM +0800, Astrodog wrote: > > Just to be sure I understand this correctly... the player stutters > when you *decrease* its priority (Or increase its niceness) only? The player stutters when I assign a realtime or idle priority to it, or when I decrease its niceness, e.g., to -10 or less. As for the priority question: AFAIK, there are 3 run queue groups in the kernel, for realtime, normal, and idle priority processes willing to run. Normal priority processes can run only if the real time queue group is empty, and idle priority processes run only if both the real time and normal queue groups are empty. My problem manifests itself if the process is not on the normal queue group. At the same time, the numeric value of its idle or realtime priority doesn't seem to matter. (Note that realtime priority of 16 and idle priority of 16 are totally different.) Therefore I cannot tell whether I increase or decrease its priority. I just move it to a different queue group. Of course, it can be said roughly that idprio(1) decreases process' priority and rtprio(1) increases it, but it isn't technically correct because the term `priority' already refers to the preference of a process within its current queue group. -- Yar