Date: Fri, 6 Mar 2015 15:30:21 +0200 From: Lena@lena.kiev.ua To: freebsd-questions@freebsd.org Cc: Rick Thomas <rbthomas@pobox.com> Subject: Re: How to adjust clock frequency in FreeBSD 10.1 ? Message-ID: <20150306133021.GC810@lena.kiev> In-Reply-To: <61602B0F-2114-4B65-A576-34EDDF94EAFA@pobox.com> References: <mailman.63.1425643201.60012.freebsd-questions@freebsd.org>
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> From: Rick Thomas <rbthomas@pobox.com> >>> I?ve got a machine with a really bad clock. Motherboards usually have several timers, not single clock. At boot time, FreeBSD kernel assigns a number called "quality" to each timer and chooses which timer to use. Using some hints in /etc/device.hints, you can forbid FreeBSD kernel to use the faulty timer. ~ $ dmesg | egrep -i 'time|clock' Timecounter "i8254" frequency 1193182 Hz quality 0 Timecounter "ACPI-fast" frequency 3579545 Hz quality 1000 acpi_timer0: <24-bit timer at 3.579545MHz> port 0x4008-0x400b on acpi0 acpi_hpet0: <High Precision Event Timer> iomem 0xfefff000-0xfefff3ff irq 0,8 on acpi0 Timecounter "HPET" frequency 25000000 Hz quality 900 atrtc0: <AT realtime clock> port 0x70-0x73 on acpi0 pmtimer0 on isa0 Timecounter "TSC" frequency 2204612489 Hz quality 800 Timecounters tick every 1.000 msec sysctl -a | egrep -i 'time|clock' | less ... kern.timecounter.choice: TSC(800) HPET(900) ACPI-fast(1000) i8254(0) dummy(-1000000) kern.timecounter.hardware: ACPI-fast If that doesn't help, look for TIMER_FREQ in /sys/i386/conf/NOTES .
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