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Diffstat (limited to 'results/classifier/gemma3:12b/kernel/1195012')
| -rw-r--r-- | results/classifier/gemma3:12b/kernel/1195012 | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/results/classifier/gemma3:12b/kernel/1195012 b/results/classifier/gemma3:12b/kernel/1195012 new file mode 100644 index 00000000..eb37186c --- /dev/null +++ b/results/classifier/gemma3:12b/kernel/1195012 @@ -0,0 +1,23 @@ + +x86_64 and i386 return 0 when reading MSR_TSC + +Running NetBSD 6.1 (i386 and amd64) under QEMU (from git - 1.5.50 is the version it shows) results in an incorrectly set +TSC frequency (set to 0), because NetBSD uses rdmsr(TSC_MSR) for its serializing CPU counter. + +To reproduce the problem, you can run an install ISO of NetBSD 6.1 (either i386 or amd64, depending on which qemu). Quit out of the installer, and you're left at a root prompt: + +# sysctl machdep.tsc_freq +machdep.tsc_freq = 0 + +...on real hardware, it will return the TSC frequency: + +# sysctl machdep.tsc_freq +machdep.tsc_freq = 3292685070 + +...this causes problems with a number of applications. + +The NetBSD code which reads the MSR is here: + +http://nxr.netbsd.org/xref/src/sys/arch/x86/x86/tsc.c#262 + +... the "rdmsr(MSR_TSC)" call in cpu_counter_serializing() always returns 0 when run under QEMU. \ No newline at end of file |