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authorAlok Kataria <akataria@vmware.com>2009-09-04 13:13:39 -0700
committerIngo Molnar <mingo@elte.hu>2009-09-20 20:25:36 +0200
commit6399c087458859cddff2d6b46befb95b866df3e0 (patch)
tree15290084df15c7999adf4e3ecbae067ab280d0fb
parentbfefb7a0c6e08736f2d5917c468467f134bf28bb (diff)
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.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index 0a46b4df5d8..1cbed97b59c 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");
}
/*