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| author | Alok Kataria <akataria@vmware.com> | 2009-09-04 13:13:39 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-09-20 20:25:36 +0200 |
| commit | 6399c087458859cddff2d6b46befb95b866df3e0 (patch) | |
| tree | 15290084df15c7999adf4e3ecbae067ab280d0fb | |
| parent | bfefb7a0c6e08736f2d5917c468467f134bf28bb (diff) | |
| download | linux-6399c087458859cddff2d6b46befb95b866df3e0.tar.bz2 | |
x86: Print the hypervisor returned tsc_khz during boot
On an AMD-64 system the processor frequency that is printed during
system boot, may be different than the tsc frequency that was
returned by the hypervisor, due to the value returned from
calibrate_cpu.
For debugging timekeeping or other related issues it might be
better to get the tsc_khz value returned by the hypervisor.
The patch below now prints the tsc frequency that the VMware
hypervisor returned.
Signed-off-by: Alok N Kataria <akataria@vmware.com>
LKML-Reference: <1252095219.12518.13.camel@ank32.eng.vmware.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | arch/x86/kernel/cpu/vmware.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c index 0a46b4df5d80..1cbed97b59cf 100644 --- a/arch/x86/kernel/cpu/vmware.c +++ b/arch/x86/kernel/cpu/vmware.c @@ -58,6 +58,9 @@ static unsigned long vmware_get_tsc_khz(void) tsc_hz = eax | (((uint64_t)ebx) << 32); do_div(tsc_hz, 1000); BUG_ON(tsc_hz >> 32); + printk(KERN_INFO "TSC freq read from hypervisor : %lu.%03lu MHz\n", + (unsigned long) tsc_hz / 1000, + (unsigned long) tsc_hz % 1000); return tsc_hz; } @@ -69,6 +72,9 @@ void __init vmware_platform_setup(void) if (ebx != UINT_MAX) x86_platform.calibrate_tsc = vmware_get_tsc_khz; + else + printk(KERN_WARNING + "Failed to get TSC freq from the hypervisor\n"); } /* |