Date: Tue, 2 Jan 2018 16:45:26 +0000 From: Gary Palmer <gpalmer@freebsd.org> To: Konstantin Belousov <kostikbel@gmail.com> Cc: freebsd-stable@freebsd.org Subject: Re: Odd behaviour on recent boot of 11.1 with timecounters Message-ID: <20180102164526.GA63396@in-addr.com> In-Reply-To: <20171231164738.GY1684@kib.kiev.ua> References: <20171231141708.GA2629@in-addr.com> <20171231145147.GW1684@kib.kiev.ua> <20171231154913.GA63310@in-addr.com> <20171231164738.GY1684@kib.kiev.ua>
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On Sun, Dec 31, 2017 at 06:47:38PM +0200, Konstantin Belousov wrote: > On Sun, Dec 31, 2017 at 03:49:13PM +0000, Gary Palmer wrote: > > On Sun, Dec 31, 2017 at 04:51:47PM +0200, Konstantin Belousov wrote: > > > On Sun, Dec 31, 2017 at 02:17:08PM +0000, Gary Palmer wrote: > > > > > > > > Hi, > > > > > > > > I recently updated to 11.1-RELEASE-p6 and on the most recent reboot > > > > (after rebuilding all the necessary packages) the clock was running > > > > slow and NTP wouldn't sync. I looked in /var/log/messages and I found > > > > that for some reason, on this latest boot, it got the frequency of > > > > TSC-low wrong. > > > > > > > > Aug 24 04:55:35 my kernel: Timecounter "TSC-low" frequency 1746073190 Hz quality 1000 > > > > Aug 26 03:11:38 my kernel: Timecounter "TSC-low" frequency 1746070760 Hz quality 1000 > > > > Aug 26 14:12:46 my kernel: Timecounter "TSC-low" frequency 1746075204 Hz quality 1000 > > > > Nov 19 16:01:09 my kernel: Timecounter "TSC-low" frequency 1746070746 Hz quality 1000 > > > > Dec 27 22:28:00 my kernel: Timecounter "TSC-low" frequency 1746074808 Hz quality 1000 > > > > Dec 27 22:51:12 my kernel: Timecounter "TSC-low" frequency 1746071892 Hz quality 1000 > > > > Dec 28 12:50:46 my kernel: Timecounter "TSC-low" frequency 1746069704 Hz quality 1000 > > > > Dec 28 14:03:52 my kernel: Timecounter "TSC-low" frequency 1937876448 Hz quality 1000 > > > > > > > > Until the December reboots the machine was running 10.x. Dec 27 and later > > > > are part of the process to get up to 11.x. > > > > > > > > Any idea why the TSC-low frequency jumped 191,806,744Hz on the last > > > > measurement? > > > > > > > > I switched to HPET temporarily via sysctl and ntp seems happy. I'm just > > > > concerned that the problem might recur on later reboots as TSC-low seems > > > > to be the preferred timecounter. > > > > > > Show first 100 lines of the dmesg from a verbose boot. > > > Also check BIOS settings related to overclocking and powersaving. > > > > > > > Hi Konstantin, > > > > BIOS settings haven't been changed in 4+ years. No overclocking, and > > all powersaving options are at "auto" or "disabled". > > > > The first 100 lines of verbose dmesg didn't seem that interesting so > > I've included up to the end of "Device configuration finished" > > > > Note that this boot didn't have the TSC-low problem, and the boot > > that had it wasn't verbose unfortunately. > > It is really the CPU identification which I wanted to see. You have > IvyBridge, which is known to have good TSC. Ah > Try to obtain verbose dmesg with mis-identified frequency. Tried, and failed after 20+ reboots. I've left boot_verbose=" -v" in /boot/loader.conf to catch any boot-time wonkiness and undone it at runtime with debug.bootverbose=0 in /etc/sysctl.conf as I found that the snd_hda driver is ... chatty at runtime. Thanks, Gary
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