id	summary	reporter	owner	description	type	status	priority	milestone	component	version	severity	resolution	keywords	cc
8759	Fix clocksource for ntp	ken@…	blfs-book@…	"One one of my machines I had to manipulate the system date/time to ensure that PDFs of different versions of a TTF font (produced by 'fret' which includes the date and time in the heading) matched.
That caused me to looked at my syslog, and I discovered that not everything was rosy.

I saw several messages like
{{{
frequency error 1726 PPM exceeds tolerance 500 PPM
}}}
although these had not previously been apparent, and something in the current kernel (after a lot of software suspends and wakens) maybe dropped the ball. However, the box was no longer synchronising.

This is apparently fixable by:
1. Check the available clock sources in cat /sys/devices/system/clocksource/clocksource0/available_clocksource
2. The default is now tsc, it used (years ago!) to be acpi_pm. Assuming
acpi_pm is available, echo that to /sys/devices/system/clocksource/clocksource0/current_clocksource
3. If things improve, add that as a boot option in grub, i.e.
clocksource=acpi_pm

At the moment I've been running with acpi_pm for a bit over a day, but I haven't rebooted to force it from grub.
"	enhancement	closed	normal	8.0	BOOK	SVN	medium	wontfix