> From: Dave Voutila <d...@sisu.io> > Date: Fri, 29 Jul 2022 10:51:20 -0400 > > Mark Kettenis <mark.kette...@xs4all.nl> writes: > > >> From: Dave Voutila <d...@sisu.io> > >> Date: Fri, 29 Jul 2022 10:10:01 -0400 > >> > >> Scott Cheloha <scottchel...@gmail.com> writes: > >> > >> > On Thu, Jul 28, 2022 at 04:57:41PM -0400, Dave Voutila wrote: > >> >> > >> >> Stuart Henderson <s...@spacehopper.org> writes: > >> >> > >> >> > On 2022/07/28 12:57, Scott Cheloha wrote: > >> >> >> On Thu, Jul 28, 2022 at 07:55:40AM -0400, Dave Voutila wrote: > >> >> >> > > >> >> >> > This is breaking timecounter selection on my x13 Ryzen 5 Pro laptop > >> >> >> > running the latest kernel from snaps. > >> >> >> > >> >> >> Define "breaking". > >> >> > > >> >> > That's clear from the output: > >> >> > > >> >> > : On 2022/07/28 07:55, Dave Voutila wrote: > >> >> > : > $ sysctl -a | grep tsc > >> >> > : > kern.timecounter.choice=i8254(0) tsc(-1000) acpihpet0(1000) > >> >> > : > acpitimer0(1000) > >> >> > : > machdep.tscfreq=2096064730 > >> >> > : > machdep.invarianttsc=1 > >> >> > : > > >> >> > : > $ sysctl kern.timecounter > >> >> > : > kern.timecounter.tick=1 > >> >> > : > kern.timecounter.timestepwarnings=0 > >> >> > : > kern.timecounter.hardware=i8254 > >> >> > : > kern.timecounter.choice=i8254(0) tsc(-1000) acpihpet0(1000) > >> >> > : > acpitimer0(1000) > >> >> > > >> >> >> The code detects TSC desync and marks the timecounter non-monotonic. > >> >> > > >> >> > That's good (and I think as would have happened before) > >> >> > > >> >> >> So it uses the i8254 instead. > >> >> > > >> >> > But that's not so good, there are higher prio timecounters available, > >> >> > acpihpet0 and acpitimer0, which would be better choices than i8254. > >> >> > >> >> Exactly my point. Thanks Stuart. > >> > > >> > Okay, please try this patch on the machine in question. > >> > >> That fixes the selection on my x13 gen1; it's choosing acpihpet0 now. No > >> issue with suspend/resume cycles either. > >> > >> Also tested the patch on my dual-socket Xeon machine and it looks to > >> still be properly synchronizing and selecting tsc as with the previous > >> diff & snapshot kernel. > >> > >> Is there any special consideration for unhiberate? I can't tell if/when > >> it is checking the TSCs across the cpus. > > > > Based on the link Scott posted yesterday, it would be interesting to > > see if there is a difference between a cold boot and a warm boot. > > Does it pick the TSC after a cold boot? And if so, what happens if > > you hibernate after a warm boot (with the HPET as source) and > > unhibernate after a cold boot. > > > > Hmm...what's the best way to force cold/warm on an x13 Ryzen system? Do > I need to do this from UEFI?
With cold boot I mean pressing the powerbutton after brining the machine down with shutdown -hp. Warm boot is simply doing a reboot.
