Date: Mon, 16 Apr 2001 17:48:13 -0700 (PDT) From: John Baldwin <jhb@FreeBSD.org> To: Mike Smith <msmith@FreeBSD.org> Cc: f-mobile <freebsd-mobile@FreeBSD.org>, parv <parv_@yahoo.com>, (Nate Williams) <nate@yogotech.com> Subject: Re: observation: clock slows down when battery power gets low Message-ID: <XFMail.010416174813.jhb@FreeBSD.org> In-Reply-To: <200104162003.f3GK36513708@mass.dis.org>
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On 16-Apr-01 Mike Smith wrote: >> > just an observation... on dell i5000e, clock slowed down >> > by about an hour and 10 minutes. didn't see anything else >> > happening. i instinctively pressed the "power" button >> > when "power" led was not shining. nothing bad happened (of >> > course, apm is disabled.). >> >> I think apm must be enabled for it to recognize the 'slowing' clock and >> deal with things correctly. >> >> Either that or completely disable power-savings... > > No, just don't use the TSC. The BIOS is winding the CPU clock back to > reduce power consumption, but the TSC code has no way of knowing that > this is going on. > > Again - do not use the TSC. Got it yet? 8) That would be easier if not doing so wasn't so cryptic to figure out from a non-kernel hacker perspective, Mike. :) Parv, You want to do: sysctl -w kern.timecounter.hardware=i8254 To make it more permament and easier, you can just stick kern.timecounter.hardware=i8254 in /etc/sysctl.conf. We really should use hte i8254 by default on laptops. I have acpi turned on so the system even knows that it has a CPU that throttles, but it still uses the TSC by default. *sigh* -- John Baldwin <jhb@FreeBSD.org> -- http://www.FreeBSD.org/~jhb/ PGP Key: http://www.baldwin.cx/~john/pgpkey.asc "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-mobile" in the body of the message
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