From 6399c087458859cddff2d6b46befb95b866df3e0 Mon Sep 17 00:00:00 2001 From: Alok Kataria <akataria@vmware.com> Date: Fri, 4 Sep 2009 13:13:39 -0700 Subject: [PATCH] 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> --- arch/x86/kernel/cpu/vmware.c | 6 ++++++ 1 file changed, 6 insertions(+) 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"); } /* -- GitLab