From owner-freebsd-current Sun Sep 17 6:53:24 2000 Delivered-To: freebsd-current@freebsd.org Received: from mailman.zeta.org.au (mailman.zeta.org.au [203.26.10.16]) by hub.freebsd.org (Postfix) with ESMTP id 4394B37B422; Sun, 17 Sep 2000 06:53:15 -0700 (PDT) Received: from bde.zeta.org.au (bde.zeta.org.au [203.2.228.102]) by mailman.zeta.org.au (8.8.7/8.8.7) with ESMTP id AAA05747; Mon, 18 Sep 2000 00:52:44 +1100 Date: Mon, 18 Sep 2000 00:52:41 +1100 (EST) From: Bruce Evans X-Sender: bde@besplex.bde.org To: Alexander Leidinger Cc: current@FreeBSD.ORG, jhb@FreeBSD.ORG Subject: Re: 100% system time? (SMPng on UP system) In-Reply-To: <200009170957.e8H9van02062@Magelan.Leidinger.net> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Sun, 17 Sep 2000, Alexander Leidinger wrote: > On 17 Sep, Bruce Evans wrote: > > >> dnetc runns with idprio 31, system cvsupped around Sep 16, 11 CEST from > >> a german mirror (it contains the idle fixes: src/sys/kern/kern_idle.c,v > >> 1.4), complete build{world,kernel}. > >> > >> ---snip--- > >> last pid: 1666; load averages: 1.10, 1.11, 1.03 up 0+00:51:21 16:54:14 > > > > Perhaps it really is a system process :-[. idprio on a pure cpu hog prevents > > other user processes from running like a system process might do: > > > > idprio 31 sh -c "while :; do :; done" > > > > System processes actually hang the entire system until they complete: > > Are you mixing idprio with rtprio or did I not understand what you > explain? You didn't understand :-). Try the example. It only uses idprio. rtprio certainly causes system hangs, and the supergiant lock may increase the problem. Before SMPng, rtprio processes prevented all non-rtprio processes including important daemons (and I think even kernel processes) from running. Starting an infinite loop at rtprio while remotely logged in was fatal because a ^C (character, not signal) to kill the process couldn't be delivered. Bruce To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message