From owner-freebsd-current Tue Sep 19 11:30:43 2000 Delivered-To: freebsd-current@freebsd.org Received: from critter.freebsd.dk (flutter.freebsd.dk [212.242.40.147]) by hub.freebsd.org (Postfix) with ESMTP id B5BD637B422 for ; Tue, 19 Sep 2000 11:30:39 -0700 (PDT) Received: from critter (localhost [127.0.0.1]) by critter.freebsd.dk (8.11.0/8.9.3) with ESMTP id e8JIUPN92162; Tue, 19 Sep 2000 20:30:26 +0200 (CEST) (envelope-from phk@critter.freebsd.dk) To: Bruce Evans Cc: "Andrey A. Chernov" , current@FreeBSD.ORG Subject: Re: recent kernel, microuptime went backwards In-Reply-To: Your message of "Wed, 20 Sep 2000 05:23:03 +1100." Date: Tue, 19 Sep 2000 20:30:25 +0200 Message-ID: <92160.969388225@critter> From: Poul-Henning Kamp Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In message , Bruce Eva ns writes: >On Tue, 19 Sep 2000, Andrey A. Chernov wrote: > >> With very latest kernel I got lots of >> >> microuptime() went backwards (1.3624050 -> 1.998840) >> >> messages just before >> >> Mounting root from ufs:/dev/da0s1a > >It really does go backwards. This is caused by the giant lock preventing >the clock interrupt task from running soon enough. The giant lock can >also prevent the clock interrupt task from running often enough even >after booting. E.g., "dd if=/dev/random of=/dev/null bs=large" does >several bad things. Yes, we are royally hosed right now with respect to interrupt service. It's a testimony to the robustness of the majority of our drivers that they don't explode more often than they do. -- 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