From owner-freebsd-arch Thu May 17 5: 2: 9 2001 Delivered-To: freebsd-arch@freebsd.org Received: from hawk.mail.pas.earthlink.net (hawk.mail.pas.earthlink.net [207.217.120.22]) by hub.freebsd.org (Postfix) with ESMTP id 2357437B424; Thu, 17 May 2001 05:02:04 -0700 (PDT) (envelope-from dleimbac@earthlink.net) Received: from 1Cust53.tnt1.starkville.ms.da.uu.net (1Cust53.tnt1.starkville.ms.da.uu.net [63.30.107.53]) by hawk.mail.pas.earthlink.net (EL-8_9_3_3/8.9.3) with ESMTP id FAA26853; Thu, 17 May 2001 05:02:00 -0700 (PDT) Message-Id: <200105171202.FAA26853@hawk.mail.pas.earthlink.net> Date: Thu, 17 May 2001 07:04:21 CDT From: dave To: Poul-Henning Kamp , Mike Smith Cc: Bruce Evans , freebsd-questions@FreeBSD.ORG, arch@FreeBSD.ORG Subject: Re: Gettimeofday Again... Reply-To: dleimbac@earthlink.net X-Mailer: Spruce 0.6.5 for X11 w/smtpio 0.7.9 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG So its then generally bad to have apm and TSC enabled? Of course the new information submitted about the Pentium IV may imply that there are ways around this. Dave On Thu, 17 May 2001, Poul-Henning Kamp wrote: > Date: Thu, 17 May 2001 10:11:47 +0200 > To: Mike Smith > From: Poul-Henning Kamp > Subject: Re: Gettimeofday Again... > > In message <200105170813.f4H8DhE01424@mass.dis.org>, Mike Smith writes: > >> > I don't change the timercounter method defaults, and I sure hope > you > >> > aren't advocating that people change their timecounter defaults. > If > >> > the TSC is a reasonable default, the system should figure it out > and > >> > use it without requiring intervention. > >> > >> It's only a reasonable default if apm (or possibly acpica) is > configured > >> (and used). > > > >The TSC is never a reasonable default; there is no good way to be > certain > >that the TSC is and/or will remain stable. Even with ACPI, you can't be > > >entirely sure. > > Right. I have tried some hybrid schemes where the TSC is interpolating > between i8254 interrupts, but it is all but impossible to maintain > continuity on a clock-throttling laptop... > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > phk@FreeBSD.ORG | TCP/IP since RFC 956 > FreeBSD committer | 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-questions" in the body of the message To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message