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From: Alok Kataria on 2 Aug 2010 19:20
Please consider the patch below for the tip tree. Thanks !

--
When running on VMware's platform, we have seen situations where
the AP's try to calibrate the lpj values and fail to get good calibration
runs becasue of timing issues. As a result delays don't work correctly
on all cpus.
The solutions is to set preset_lpj value based on the current tsc frequency
value. This is similar to what KVM does as well.

Signed-off-by: Alok N Kataria <akataria(a)vmware.com>

Index: linux-x86-tree.git/arch/x86/kernel/cpu/vmware.c
===================================================================
--- linux-x86-tree.git.orig/arch/x86/kernel/cpu/vmware.c 2010-08-02 15:43:28.000000000 -0700
+++ linux-x86-tree.git/arch/x86/kernel/cpu/vmware.c 2010-08-02 15:43:37.000000000 -0700
@@ -51,7 +51,7 @@ static inline int __vmware_platform(void

static unsigned long vmware_get_tsc_khz(void)
{
- uint64_t tsc_hz;
+ uint64_t tsc_hz, lpj;
uint32_t eax, ebx, ecx, edx;

VMWARE_PORT(GETHZ, eax, ebx, ecx, edx);
@@ -62,6 +62,13 @@ static unsigned long vmware_get_tsc_khz(
printk(KERN_INFO "TSC freq read from hypervisor : %lu.%03lu MHz\n",
(unsigned long) tsc_hz / 1000,
(unsigned long) tsc_hz % 1000);
+
+ if (!preset_lpj) {
+ lpj = ((u64)tsc_hz * 1000);
+ do_div(lpj, HZ);
+ preset_lpj = lpj;
+ }
+
return tsc_hz;
}



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