Date: Sun, 17 Sep 2000 15:57:18 +0200 From: Poul-Henning Kamp <phk@critter.freebsd.dk> To: Bruce Evans <bde@zeta.org.au> Cc: Alexander Leidinger <Alexander@leidinger.net>, current@FreeBSD.ORG, jhb@FreeBSD.ORG Subject: Re: 100% system time? (SMPng on UP system) Message-ID: <78779.969199038@critter> In-Reply-To: Your message of "Mon, 18 Sep 2000 00:52:41 %2B1100." <Pine.BSF.4.21.0009180034230.11515-100000@besplex.bde.org>
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In message <Pine.BSF.4.21.0009180034230.11515-100000@besplex.bde.org>, Bruce Ev ans writes: >> > 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. I can confirm this one, ntpd has for a long time pointlessly raised it's priority to the absolute maximum, and if during debugging it went into a spin it would freeze the system. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD coreteam member | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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