For a while now TSC has not worked out of the box unless I add tsc=nowatchdog to my kernel command line.
There is quite a large performance cost to TSC not being enabled in time sensitive applications.
Which Linux distro are you using? - Arch
(If rolling release, last date updated?) Today
Which kernel are you using? 6.16.5-arch1-1
Which BIOS version are you using? 3.09
Which Framework Laptop 13 model are you using? - AMD Ryzen™ 7040 Series
Stock
tsc=nowatchdog
On Fedora here, same CPU. I only see it sporadically (once) in the past three months through quite a few kernel versions. Some distro-specific patch causing/fixing it?
$ journalctl --no-hostname --since '3 months ago' |egrep 'TSC|Linux version'
Jun 11 09:56:12 kernel: Linux version 6.14.11-300.fc42.x86_64 (mockbuild@11674b482ddb43858b0c88fcfc0eea08) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-3.fc42) #1 SMP PREEMPT_DYNAMIC Tue Jun 10 16:24:16 UTC 2025
Jun 11 09:56:12 kernel: tsc: Fast TSC calibration using PIT
Jun 11 09:56:13 kernel: tsc: Refined TSC clocksource calibration: 3293.781 MHz
Jun 11 09:56:28 kernel: kvm_amd: TSC scaling supported
Jun 16 09:11:06 kernel: Linux version 6.14.11-300.fc42.x86_64 (mockbuild@11674b482ddb43858b0c88fcfc0eea08) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-3.fc42) #1 SMP PREEMPT_DYNAMIC Tue Jun 10 16:24:16 UTC 2025
Jun 16 09:11:06 kernel: tsc: Fast TSC calibration using PIT
Jun 16 09:11:07 kernel: tsc: Refined TSC clocksource calibration: 3293.806 MHz
Jun 16 09:11:23 kernel: kvm_amd: TSC scaling supported
Jun 17 09:34:15 kernel: Linux version 6.14.11-300.fc42.x86_64 (mockbuild@11674b482ddb43858b0c88fcfc0eea08) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-3.fc42) #1 SMP PREEMPT_DYNAMIC Tue Jun 10 16:24:16 UTC 2025
Jun 17 09:34:15 kernel: tsc: Fast TSC calibration using PIT
Jun 17 09:34:16 kernel: tsc: Refined TSC clocksource calibration: 3293.791 MHz
Jun 17 09:34:36 kernel: kvm_amd: TSC scaling supported
Jun 17 14:27:09 kernel: Linux version 6.14.11-300.fc42.x86_64 (mockbuild@11674b482ddb43858b0c88fcfc0eea08) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-3.fc42) #1 SMP PREEMPT_DYNAMIC Tue Jun 10 16:24:16 UTC 2025
Jun 17 14:27:09 kernel: tsc: Fast TSC calibration using PIT
Jun 17 14:27:10 kernel: tsc: Refined TSC clocksource calibration: 3293.799 MHz
Jun 17 14:27:30 kernel: kvm_amd: TSC scaling supported
Jun 19 09:47:00 kernel: Linux version 6.14.11-300.fc42.x86_64 (mockbuild@11674b482ddb43858b0c88fcfc0eea08) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-3.fc42) #1 SMP PREEMPT_DYNAMIC Tue Jun 10 16:24:16 UTC 2025
Jun 19 09:47:00 kernel: tsc: Fast TSC calibration using PIT
Jun 19 09:47:01 kernel: tsc: Refined TSC clocksource calibration: 3293.783 MHz
Jun 19 09:47:19 kernel: kvm_amd: TSC scaling supported
Jun 21 10:37:11 kernel: Linux version 6.15.3-200.fc42.x86_64 (mockbuild@6b3cf248b5d84b6eb711635947975ce2) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-3.fc42) #1 SMP PREEMPT_DYNAMIC Thu Jun 19 15:00:25 UTC 2025
Jun 21 10:37:11 kernel: tsc: Fast TSC calibration using PIT
Jun 21 10:37:12 kernel: tsc: Refined TSC clocksource calibration: 3293.810 MHz
Jun 21 10:38:01 kernel: kvm_amd: TSC scaling supported
Jun 24 09:32:28 kernel: Linux version 6.15.3-200.fc42.x86_64 (mockbuild@6b3cf248b5d84b6eb711635947975ce2) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-3.fc42) #1 SMP PREEMPT_DYNAMIC Thu Jun 19 15:00:25 UTC 2025
Jun 24 09:32:28 kernel: tsc: Fast TSC calibration using PIT
Jun 24 09:32:29 kernel: tsc: Refined TSC clocksource calibration: 3293.814 MHz
Jun 24 09:33:01 kernel: kvm_amd: TSC scaling supported
Jun 25 11:11:24 kernel: Linux version 6.15.3-200.fc42.x86_64 (mockbuild@6b3cf248b5d84b6eb711635947975ce2) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-3.fc42) #1 SMP PREEMPT_DYNAMIC Thu Jun 19 15:00:25 UTC 2025
Jun 25 11:11:24 kernel: tsc: Fast TSC calibration using PIT
Jun 25 11:11:25 kernel: tsc: Refined TSC clocksource calibration: 3293.791 MHz
Jun 25 11:11:50 kernel: kvm_amd: TSC scaling supported
Jun 27 09:17:12 kernel: Linux version 6.15.3-200.fc42.x86_64 (mockbuild@6b3cf248b5d84b6eb711635947975ce2) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-3.fc42) #1 SMP PREEMPT_DYNAMIC Thu Jun 19 15:00:25 UTC 2025
Jun 27 09:17:12 kernel: tsc: Fast TSC calibration using PIT
Jun 27 09:17:13 kernel: tsc: Refined TSC clocksource calibration: 3293.813 MHz
Jun 27 09:17:28 kernel: kvm_amd: TSC scaling supported
Jun 27 10:02:01 kernel: Linux version 6.15.3-200.fc42.x86_64 (mockbuild@6b3cf248b5d84b6eb711635947975ce2) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-3.fc42) #1 SMP PREEMPT_DYNAMIC Thu Jun 19 15:00:25 UTC 2025
Jun 27 10:02:01 kernel: tsc: Fast TSC calibration using PIT
Jun 27 10:02:02 kernel: tsc: Refined TSC clocksource calibration: 3293.813 MHz
Jun 27 10:02:17 kernel: kvm_amd: TSC scaling supported
Jun 28 11:54:01 kernel: Linux version 6.15.4-200.fc42.x86_64 (mockbuild@d2195f98ab4b4400b4eac9c028c691e1) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-3.fc42) #1 SMP PREEMPT_DYNAMIC Fri Jun 27 15:32:46 UTC 2025
Jun 28 11:54:01 kernel: tsc: Fast TSC calibration using PIT
Jun 28 11:54:02 kernel: tsc: Refined TSC clocksource calibration: 3293.802 MHz
Jun 28 11:55:03 kernel: kvm_amd: TSC scaling supported
Jun 30 10:02:23 kernel: Linux version 6.15.4-200.fc42.x86_64 (mockbuild@d2195f98ab4b4400b4eac9c028c691e1) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-3.fc42) #1 SMP PREEMPT_DYNAMIC Fri Jun 27 15:32:46 UTC 2025
Jun 30 10:02:23 kernel: tsc: Fast TSC calibration using PIT
Jun 30 10:02:24 kernel: tsc: Refined TSC clocksource calibration: 3293.814 MHz
Jun 30 10:02:39 kernel: kvm_amd: TSC scaling supported
Jul 08 15:21:22 kernel: Linux version 6.15.4-200.fc42.x86_64 (mockbuild@d2195f98ab4b4400b4eac9c028c691e1) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-3.fc42) #1 SMP PREEMPT_DYNAMIC Fri Jun 27 15:32:46 UTC 2025
Jul 08 15:21:22 kernel: tsc: Fast TSC calibration using PIT
Jul 08 15:21:23 kernel: tsc: Refined TSC clocksource calibration: 3293.825 MHz
Jul 08 15:21:39 kernel: kvm_amd: TSC scaling supported
Jul 08 20:16:14 kernel: Linux version 6.15.5-200.fc42.x86_64 (mockbuild@19bc9e0c12a449f58c5843ef10b48a7e) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-3.fc42) #1 SMP PREEMPT_DYNAMIC Sun Jul 6 09:16:17 UTC 2025
Jul 08 20:16:14 kernel: tsc: Fast TSC calibration using PIT
Jul 08 20:16:15 kernel: tsc: Refined TSC clocksource calibration: 3293.812 MHz
Jul 08 20:16:35 kernel: kvm_amd: TSC scaling supported
Jul 11 09:20:37 kernel: Linux version 6.15.5-200.fc42.x86_64 (mockbuild@19bc9e0c12a449f58c5843ef10b48a7e) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-3.fc42) #1 SMP PREEMPT_DYNAMIC Sun Jul 6 09:16:17 UTC 2025
Jul 11 09:20:37 kernel: tsc: Fast TSC calibration using PIT
Jul 11 09:20:38 kernel: tsc: Refined TSC clocksource calibration: 3293.812 MHz
Jul 11 09:20:59 kernel: kvm_amd: TSC scaling supported
Jul 11 19:29:31 kernel: Linux version 6.15.6-200.fc42.x86_64 (mockbuild@ff97bdaf838846f1a7c43bb5f265d7af) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-3.fc42) #1 SMP PREEMPT_DYNAMIC Thu Jul 10 15:22:32 UTC 2025
Jul 11 19:29:31 kernel: tsc: Fast TSC calibration using PIT
Jul 11 19:29:32 kernel: tsc: Refined TSC clocksource calibration: 3293.807 MHz
Jul 11 19:29:58 kernel: kvm_amd: TSC scaling supported
Jul 12 17:06:09 kernel: Linux version 6.15.6-200.fc42.x86_64 (mockbuild@ff97bdaf838846f1a7c43bb5f265d7af) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-3.fc42) #1 SMP PREEMPT_DYNAMIC Thu Jul 10 15:22:32 UTC 2025
Jul 12 17:06:09 kernel: tsc: Fast TSC calibration using PIT
Jul 12 17:06:10 kernel: tsc: Refined TSC clocksource calibration: 3293.845 MHz
Jul 12 17:06:29 kernel: kvm_amd: TSC scaling supported
Jul 17 09:02:38 kernel: Linux version 6.15.6-200.fc42.x86_64 (mockbuild@ff97bdaf838846f1a7c43bb5f265d7af) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-3.fc42) #1 SMP PREEMPT_DYNAMIC Thu Jul 10 15:22:32 UTC 2025
Jul 17 09:02:38 kernel: tsc: Fast TSC calibration using PIT
Jul 17 09:02:39 kernel: tsc: Refined TSC clocksource calibration: 3293.798 MHz
Jul 17 09:03:34 kernel: kvm_amd: TSC scaling supported
Jul 19 18:23:03 kernel: Linux version 6.15.7-200.fc42.x86_64 (mockbuild@5da7262c50a0401890423524c10adde0) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-3.fc42) #1 SMP PREEMPT_DYNAMIC Thu Jul 17 17:57:16 UTC 2025
Jul 19 18:23:03 kernel: tsc: Fast TSC calibration using PIT
Jul 19 18:23:04 kernel: tsc: Refined TSC clocksource calibration: 3293.840 MHz
Jul 19 18:23:25 kernel: kvm_amd: TSC scaling supported
Jul 21 20:13:31 kernel: Linux version 6.15.7-200.fc42.x86_64 (mockbuild@5da7262c50a0401890423524c10adde0) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-3.fc42) #1 SMP PREEMPT_DYNAMIC Thu Jul 17 17:57:16 UTC 2025
Jul 21 20:13:31 kernel: tsc: Fast TSC calibration using PIT
Jul 21 20:13:32 kernel: tsc: Refined TSC clocksource calibration: 3293.812 MHz
Jul 21 20:14:36 kernel: kvm_amd: TSC scaling supported
Jul 21 20:16:19 kernel: Linux version 6.15.7-200.fc42.x86_64 (mockbuild@5da7262c50a0401890423524c10adde0) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-3.fc42) #1 SMP PREEMPT_DYNAMIC Thu Jul 17 17:57:16 UTC 2025
Jul 21 20:16:19 kernel: tsc: Fast TSC calibration using PIT
Jul 21 20:16:20 kernel: tsc: Refined TSC clocksource calibration: 3293.787 MHz
Jul 21 20:16:38 kernel: kvm_amd: TSC scaling supported
Jul 22 19:12:11 kernel: Linux version 6.15.7-200.fc42.x86_64 (mockbuild@5da7262c50a0401890423524c10adde0) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-3.fc42) #1 SMP PREEMPT_DYNAMIC Thu Jul 17 17:57:16 UTC 2025
Jul 22 19:12:11 kernel: tsc: Fast TSC calibration using PIT
Jul 22 19:12:12 kernel: tsc: Refined TSC clocksource calibration: 3293.780 MHz
Jul 22 19:12:30 kernel: kvm_amd: TSC scaling supported
Jul 23 08:49:08 kernel: Linux version 6.15.7-200.fc42.x86_64 (mockbuild@5da7262c50a0401890423524c10adde0) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-3.fc42) #1 SMP PREEMPT_DYNAMIC Thu Jul 17 17:57:16 UTC 2025
Jul 23 08:49:08 kernel: tsc: Fast TSC calibration using PIT
Jul 23 08:49:09 kernel: tsc: Refined TSC clocksource calibration: 3293.811 MHz
Jul 23 08:49:37 kernel: kvm_amd: TSC scaling supported
Jul 24 18:51:58 kernel: tsc: Marking TSC unstable due to clocksource watchdog
Jul 24 18:51:58 kernel: TSC found unstable after boot, most likely due to broken BIOS. Use 'tsc=unstable'.
Jul 25 11:38:56 kernel: Linux version 6.15.8-200.fc42.x86_64 (mockbuild@93f30e7b946b413d81e83e0dc19ac3a8) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-5.fc42) #1 SMP PREEMPT_DYNAMIC Thu Jul 24 13:26:52 UTC 2025
Jul 25 11:38:56 kernel: tsc: Fast TSC calibration using PIT
Jul 25 11:38:57 kernel: tsc: Refined TSC clocksource calibration: 3293.795 MHz
Jul 25 11:39:13 kernel: kvm_amd: TSC scaling supported
Jul 26 11:10:38 kernel: Linux version 6.15.8-200.fc42.x86_64 (mockbuild@93f30e7b946b413d81e83e0dc19ac3a8) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-5.fc42) #1 SMP PREEMPT_DYNAMIC Thu Jul 24 13:26:52 UTC 2025
Jul 26 11:10:38 kernel: tsc: Fast TSC calibration using PIT
Jul 26 11:10:39 kernel: tsc: Refined TSC clocksource calibration: 3293.780 MHz
Jul 26 11:11:00 kernel: kvm_amd: TSC scaling supported
Jul 30 14:10:06 kernel: Linux version 6.15.8-200.fc42.x86_64 (mockbuild@93f30e7b946b413d81e83e0dc19ac3a8) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-5.fc42) #1 SMP PREEMPT_DYNAMIC Thu Jul 24 13:26:52 UTC 2025
Jul 30 14:10:06 kernel: tsc: Fast TSC calibration using PIT
Jul 30 14:10:07 kernel: tsc: Refined TSC clocksource calibration: 3293.820 MHz
Jul 30 14:10:27 kernel: kvm_amd: TSC scaling supported
Aug 01 09:50:20 kernel: Linux version 6.15.8-200.fc42.x86_64 (mockbuild@93f30e7b946b413d81e83e0dc19ac3a8) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-5.fc42) #1 SMP PREEMPT_DYNAMIC Thu Jul 24 13:26:52 UTC 2025
Aug 01 09:50:20 kernel: tsc: Fast TSC calibration using PIT
Aug 01 09:50:21 kernel: tsc: Refined TSC clocksource calibration: 3293.811 MHz
Aug 01 09:50:41 kernel: kvm_amd: TSC scaling supported
Aug 03 12:58:14 kernel: Linux version 6.15.9-201.fc42.x86_64 (mockbuild@fcd66b5b9bf7458aab425e003fa252bc) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Sat Aug 2 11:37:34 UTC 2025
Aug 03 12:58:14 kernel: tsc: Fast TSC calibration using PIT
Aug 03 12:58:15 kernel: tsc: Refined TSC clocksource calibration: 3293.813 MHz
Aug 03 12:59:42 kernel: kvm_amd: TSC scaling supported
Aug 03 13:07:13 kernel: Linux version 6.15.9-201.fc42.x86_64 (mockbuild@fcd66b5b9bf7458aab425e003fa252bc) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Sat Aug 2 11:37:34 UTC 2025
Aug 03 13:07:13 kernel: tsc: Fast TSC calibration using PIT
Aug 03 13:07:14 kernel: tsc: Refined TSC clocksource calibration: 3293.780 MHz
Aug 03 13:07:54 kernel: kvm_amd: TSC scaling supported
Aug 04 09:56:31 kernel: Linux version 6.15.9-201.fc42.x86_64 (mockbuild@fcd66b5b9bf7458aab425e003fa252bc) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Sat Aug 2 11:37:34 UTC 2025
Aug 04 09:56:31 kernel: tsc: Fast TSC calibration using PIT
Aug 04 09:56:32 kernel: tsc: Refined TSC clocksource calibration: 3293.778 MHz
Aug 04 09:57:07 kernel: kvm_amd: TSC scaling supported
Aug 04 10:48:21 kernel: Linux version 6.15.9-201.fc42.x86_64 (mockbuild@fcd66b5b9bf7458aab425e003fa252bc) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Sat Aug 2 11:37:34 UTC 2025
Aug 04 10:48:21 kernel: tsc: Fast TSC calibration using PIT
Aug 04 10:48:22 kernel: tsc: Refined TSC clocksource calibration: 3293.797 MHz
Aug 04 10:49:51 kernel: kvm_amd: TSC scaling supported
Aug 07 10:03:42 kernel: Linux version 6.15.9-201.fc42.x86_64 (mockbuild@fcd66b5b9bf7458aab425e003fa252bc) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Sat Aug 2 11:37:34 UTC 2025
Aug 07 10:03:42 kernel: tsc: Fast TSC calibration using PIT
Aug 07 10:03:43 kernel: tsc: Refined TSC clocksource calibration: 3293.791 MHz
Aug 07 10:04:05 kernel: kvm_amd: TSC scaling supported
Aug 09 13:16:35 kernel: Linux version 6.15.9-201.fc42.x86_64 (mockbuild@fcd66b5b9bf7458aab425e003fa252bc) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Sat Aug 2 11:37:34 UTC 2025
Aug 09 13:16:35 kernel: tsc: Fast TSC calibration using PIT
Aug 09 13:16:36 kernel: tsc: Refined TSC clocksource calibration: 3293.799 MHz
Aug 09 13:18:13 kernel: kvm_amd: TSC scaling supported
Aug 11 10:56:07 kernel: Linux version 6.15.9-201.fc42.x86_64 (mockbuild@fcd66b5b9bf7458aab425e003fa252bc) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Sat Aug 2 11:37:34 UTC 2025
Aug 11 10:56:07 kernel: tsc: Fast TSC calibration using PIT
Aug 11 10:56:08 kernel: tsc: Refined TSC clocksource calibration: 3293.851 MHz
Aug 11 10:56:28 kernel: kvm_amd: TSC scaling supported
Aug 11 16:26:56 kernel: Linux version 6.15.9-201.fc42.x86_64 (mockbuild@fcd66b5b9bf7458aab425e003fa252bc) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Sat Aug 2 11:37:34 UTC 2025
Aug 11 16:26:56 kernel: tsc: Fast TSC calibration using PIT
Aug 11 16:26:57 kernel: tsc: Refined TSC clocksource calibration: 3293.812 MHz
Aug 11 16:27:18 kernel: kvm_amd: TSC scaling supported
Aug 13 08:51:23 kernel: Linux version 6.15.9-201.fc42.x86_64 (mockbuild@fcd66b5b9bf7458aab425e003fa252bc) (gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Sat Aug 2 11:37:34 UTC 2025
Aug 13 08:51:23 kernel: tsc: Fast TSC calibration using PIT
Aug 13 08:51:24 kernel: tsc: Refined TSC clocksource calibration: 3293.780 MHz
Aug 13 08:51:43 kernel: kvm_amd: TSC scaling supported
Aug 16 14:11:02 kernel: Linux version 6.15.10-200.fc42.x86_64 (mockbuild@14a33d64645143cab3659d1335d9f80c) (gcc (GCC) 15.2.1 20250808 (Red Hat 15.2.1-1), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Fri Aug 15 15:57:06 UTC 2025
Aug 16 14:11:02 kernel: tsc: Fast TSC calibration using PIT
Aug 16 14:11:03 kernel: tsc: Refined TSC clocksource calibration: 3293.798 MHz
Aug 16 14:11:22 kernel: kvm_amd: TSC scaling supported
Aug 17 21:29:10 kernel: Linux version 6.15.10-200.fc42.x86_64 (mockbuild@14a33d64645143cab3659d1335d9f80c) (gcc (GCC) 15.2.1 20250808 (Red Hat 15.2.1-1), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Fri Aug 15 15:57:06 UTC 2025
Aug 17 21:29:10 kernel: tsc: Fast TSC calibration using PIT
Aug 17 21:29:11 kernel: tsc: Refined TSC clocksource calibration: 3293.811 MHz
Aug 17 21:29:38 kernel: kvm_amd: TSC scaling supported
Aug 17 21:33:14 kernel: Linux version 6.15.10-200.fc42.x86_64 (mockbuild@14a33d64645143cab3659d1335d9f80c) (gcc (GCC) 15.2.1 20250808 (Red Hat 15.2.1-1), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Fri Aug 15 15:57:06 UTC 2025
Aug 17 21:33:14 kernel: tsc: Fast TSC calibration using PIT
Aug 17 21:33:15 kernel: tsc: Refined TSC clocksource calibration: 3293.793 MHz
Aug 17 21:34:10 kernel: kvm_amd: TSC scaling supported
Aug 17 21:40:22 kernel: Linux version 6.15.10-200.fc42.x86_64 (mockbuild@14a33d64645143cab3659d1335d9f80c) (gcc (GCC) 15.2.1 20250808 (Red Hat 15.2.1-1), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Fri Aug 15 15:57:06 UTC 2025
Aug 17 21:40:22 kernel: tsc: Fast TSC calibration using PIT
Aug 17 21:40:23 kernel: tsc: Refined TSC clocksource calibration: 3293.777 MHz
Aug 17 21:40:40 kernel: kvm_amd: TSC scaling supported
Aug 17 21:42:51 kernel: Linux version 6.15.10-200.fc42.x86_64 (mockbuild@14a33d64645143cab3659d1335d9f80c) (gcc (GCC) 15.2.1 20250808 (Red Hat 15.2.1-1), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Fri Aug 15 15:57:06 UTC 2025
Aug 17 21:42:51 kernel: tsc: Fast TSC calibration using PIT
Aug 17 21:42:52 kernel: tsc: Refined TSC clocksource calibration: 3293.783 MHz
Aug 17 21:43:10 kernel: kvm_amd: TSC scaling supported
Aug 17 21:51:51 kernel: Linux version 6.15.10-200.fc42.x86_64 (mockbuild@14a33d64645143cab3659d1335d9f80c) (gcc (GCC) 15.2.1 20250808 (Red Hat 15.2.1-1), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Fri Aug 15 15:57:06 UTC 2025
Aug 17 21:51:51 kernel: tsc: Fast TSC calibration using PIT
Aug 17 21:51:52 kernel: tsc: Refined TSC clocksource calibration: 3293.809 MHz
Aug 17 21:52:10 kernel: kvm_amd: TSC scaling supported
Aug 19 09:08:49 kernel: Linux version 6.15.10-200.fc42.x86_64 (mockbuild@14a33d64645143cab3659d1335d9f80c) (gcc (GCC) 15.2.1 20250808 (Red Hat 15.2.1-1), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Fri Aug 15 15:57:06 UTC 2025
Aug 19 09:08:49 kernel: tsc: Fast TSC calibration using PIT
Aug 19 09:08:50 kernel: tsc: Refined TSC clocksource calibration: 3293.813 MHz
Aug 19 09:09:30 kernel: kvm_amd: TSC scaling supported
Aug 19 09:11:38 kernel: Linux version 6.15.10-200.fc42.x86_64 (mockbuild@14a33d64645143cab3659d1335d9f80c) (gcc (GCC) 15.2.1 20250808 (Red Hat 15.2.1-1), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Fri Aug 15 15:57:06 UTC 2025
Aug 19 09:11:38 kernel: tsc: Fast TSC calibration using PIT
Aug 19 09:11:39 kernel: tsc: Refined TSC clocksource calibration: 3293.783 MHz
Aug 19 09:12:02 kernel: kvm_amd: TSC scaling supported
Aug 19 09:55:04 kernel: Linux version 6.15.10-200.fc42.x86_64 (mockbuild@14a33d64645143cab3659d1335d9f80c) (gcc (GCC) 15.2.1 20250808 (Red Hat 15.2.1-1), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Fri Aug 15 15:57:06 UTC 2025
Aug 19 09:55:04 kernel: tsc: Fast TSC calibration using PIT
Aug 19 09:55:05 kernel: tsc: Refined TSC clocksource calibration: 3293.786 MHz
Aug 19 09:55:25 kernel: kvm_amd: TSC scaling supported
Aug 21 20:57:31 kernel: Linux version 6.16.2-200.fc42.x86_64 (mockbuild@a4d6bf134bb54715a329534df16b323a) (gcc (GCC) 15.2.1 20250808 (Red Hat 15.2.1-1), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Wed Aug 20 21:10:33 UTC 2025
Aug 21 20:57:31 kernel: tsc: Fast TSC calibration using PIT
Aug 21 20:57:32 kernel: tsc: Refined TSC clocksource calibration: 3293.787 MHz
Aug 21 20:57:50 kernel: kvm_amd: TSC scaling supported
Aug 23 09:04:44 kernel: Linux version 6.16.2-200.fc42.x86_64 (mockbuild@a4d6bf134bb54715a329534df16b323a) (gcc (GCC) 15.2.1 20250808 (Red Hat 15.2.1-1), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Wed Aug 20 21:10:33 UTC 2025
Aug 23 09:04:44 kernel: tsc: Fast TSC calibration using PIT
Aug 23 09:04:45 kernel: tsc: Refined TSC clocksource calibration: 3293.828 MHz
Aug 23 09:05:04 kernel: kvm_amd: TSC scaling supported
Aug 25 08:52:53 kernel: Linux version 6.16.3-200.fc42.x86_64 (mockbuild@8351c3197d794bd8b16d5b0f4cd94c69) (gcc (GCC) 15.2.1 20250808 (Red Hat 15.2.1-1), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Sat Aug 23 17:02:17 UTC 2025
Aug 25 08:52:53 kernel: tsc: Fast TSC calibration using PIT
Aug 25 08:52:54 kernel: tsc: Refined TSC clocksource calibration: 3293.848 MHz
Aug 25 08:53:13 kernel: kvm_amd: TSC scaling supported
Aug 27 12:54:36 kernel: Linux version 6.16.3-200.fc42.x86_64 (mockbuild@8351c3197d794bd8b16d5b0f4cd94c69) (gcc (GCC) 15.2.1 20250808 (Red Hat 15.2.1-1), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Sat Aug 23 17:02:17 UTC 2025
Aug 27 12:54:36 kernel: tsc: Fast TSC calibration using PIT
Aug 27 12:54:37 kernel: tsc: Refined TSC clocksource calibration: 3293.813 MHz
Aug 27 12:55:02 kernel: kvm_amd: TSC scaling supported
Aug 31 09:40:36 kernel: Linux version 6.16.4-200.fc42.x86_64 (mockbuild@8b6205bdb3654e74a5b414670352dcf2) (gcc (GCC) 15.2.1 20250808 (Red Hat 15.2.1-1), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Thu Aug 28 19:47:10 UTC 2025
Aug 31 09:40:36 kernel: tsc: Fast TSC calibration using PIT
Aug 31 09:40:37 kernel: tsc: Refined TSC clocksource calibration: 3293.801 MHz
Aug 31 09:42:19 kernel: kvm_amd: TSC scaling supported
Sep 05 12:53:05 kernel: Linux version 6.16.5-200.fc42.x86_64 (mockbuild@7189bd5ddf394040a46ecf06491cd0d3) (gcc (GCC) 15.2.1 20250808 (Red Hat 15.2.1-1), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Thu Sep 4 16:37:21 UTC 2025
Sep 05 12:53:05 kernel: tsc: Fast TSC calibration using PIT
Sep 05 12:53:06 kernel: tsc: Refined TSC clocksource calibration: 3293.802 MHz
Sep 05 12:53:31 kernel: kvm_amd: TSC scaling supported
Sep 06 14:02:18 kernel: Linux version 6.16.5-200.fc42.x86_64 (mockbuild@7189bd5ddf394040a46ecf06491cd0d3) (gcc (GCC) 15.2.1 20250808 (Red Hat 15.2.1-1), GNU ld version 2.44-6.fc42) #1 SMP PREEMPT_DYNAMIC Thu Sep 4 16:37:21 UTC 2025
Sep 06 14:02:18 kernel: tsc: Fast TSC calibration using PIT
Sep 06 14:02:19 kernel: tsc: Refined TSC clocksource calibration: 3293.795 MHz
Sep 06 14:02:36 kernel: kvm_amd: TSC scaling supported
(edit: only non-default kernel cmdline arg is the amdgpu.dcdebugmask=0x10 display workaround.
I will do some tests with fedora and see what I find.
Edit: Thanks for sharing your logs.
I have the same gen and distro and it seems to happen very sporadically, mostly right before suspension. I’d recommend updating the firmware to 3.16 if you plan on filing a bug report.
I’d also be willing to test patches or assist in debugging this further.
Can you actually replicate this on every boot? W/o suspension, hibernation, reboot vs shutdown, etc.?
Sorry I believe my laptop is actually on 3.16 I remember updating the firmware very recently. I’ll double confirm that tonight.
Additionally the tsc fails intermittently on boot for me but I have seen it only fail after a suspended then wake from suspend as well.
I’m having the same issue here. I found out recently due to (substantial) perf regressions on our software, the fallback to hpet as a clocksource meant no more vdso for clock_gettime, leading to a major perf hit.
Disabling the watchdog is a band aid but a real fix should come from the bios.
And I’m running 3.16. It happens on cold boot nearly all the time.
Same on Fedora 42 and 43. Bios 3.16.