On Thu, Apr 01, 2021 at 06:43:30PM -0500, Scott Cheloha wrote: > On Thu, Apr 01, 2021 at 03:41:24PM -0400, Josh Rickmar wrote: > > On Thu, Apr 01, 2021 at 03:22:00PM -0400, Josh Rickmar wrote: > > > On Thu, Apr 01, 2021 at 02:15:48PM -0500, Scott Cheloha wrote: > > > > On Sat, Mar 27, 2021 at 02:20:21AM +0000, Stefmorino wrote: > > > > > > Feel free to share your raw data. > > > > > > > > > > Also includes some standard sendbug dumps: https://0x0.st/-qng.tgz > > > > > > > > Thanks! > > > > > > > > TL;DR: > > > > > > > > Two things: > > > > > > > > 1. Could you check whether Linux will use the TSC as a clocksource on > > > > this machine? The dmesg output on any given distribution should > > > > contain lines about the TSC. > > > > > > > > [...] > > > > > > > Hey, thanks for the reminder to try this out with Linux. Will give it > > > a shot shortly. > > > > > > As for the BIOS, 1.58 is the current version (found here): > > > > > > https://support.lenovo.com/us/en/downloads/ds503790 > > > > > > This same issue was happening with all older BIOS versions that I have > > > used as well. > > Okay, not great news, but at least the behavior is consistent. > > > Seems Linux doesn't like it either: > > > > localhost:~# dmesg | egrep -i 'tsc|clocksource' > > [ 0.000000] tsc: Fast TSC calibration using PIT > > [ 0.000000] tsc: Detected 1996.173 MHz processor > > [ 0.043227] clocksource: refined-jiffies: mask: 0xffffffff max_cycles: > > 0xffffffff, max_idle_ms: 6370452778343963 ns > > [ 0.114728] clocksource: hpet: mask: 0xffffffff max_cycles: 0xffffffff, > > max_idle_ns: 133484873504 ns > > [ 0.131435] clocksource: tsc-early: mask: 0xffffffffffffffff max_cycles: > > 0x398c1ebcd00, max_idle_ns: 881590807727 ns > > [ 0.244772] TSC synchronization [CPU#0 -> CPU#1]: > > [ 0.244772] Measured 7296391160 warp between CPUs, turning off TSC clock. > > [ 0.244772] tsc: Marking TSC unstable due to check_tsc_sync_source_failed > > [ 0.252185] clocksource: jiffies: mask: 0xffffffff max_cycles: > > 0xffffffff, max_idle_ns: 6370867519511994 ns > > [ 0.316884] clocksource: Switched to clocksource hpet > > [ 0.335046] clocksource: acpi_pm: mask: 0xffffff max_cycles: 0xffffff, > > max_idle_ns: 2085701024 ns > > Hmmm. Being able to work around this would be nice. > > FreeBSD has code that uses WRMSR to synchronize the TSC: > > https://cgit.freebsd.org/src/commit/sys/x86/x86/tsc.c?id=b2c63698d4b81576e0c8842263ee86e86cd34e76 > > My guess is that support for writing the TSC is not implemented by > every hypervisor, so we would need to be very careful in deciding when > to try it. Otherwise we end up with protection faults and other crap > we don't want. > > Doing this via TSC_ADJUST (instead of writing the TSC directly) is > nicer because you just check for the CPUID level and bit. No > guesswork. But we can't in your case because, as I said, no > TSC_ADJUST support on your CPU.
This seems to be a common problem among most Ryzen Thinkpads. https://bugzilla.kernel.org/show_bug.cgi?id=202525 Oddly enough, the A485/A585 seems to have gotten a BIOS patch (v1.28, Nov 2019) that fixes this, but no other models that I can see.
