path: root/arch
diff options
authorAlok Kataria <akataria@vmware.com>2010-08-02 16:10:37 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2010-08-13 13:30:36 -0700
commit94f6da84e80c01e655df88479d7b57a6d89965f2 (patch)
treef16369a50ddbf2a79923b0e78bbbf1ab6f709d3a /arch
parent3f3ed15762e959843793763db4aac37cc9bd9644 (diff)
x86, vmware: Preset lpj values when on VMware.
commit 9f242dc10e0c3c1eb32d8c83c18650a35fd7f80d upstream. 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@vmware.com> LKML-Reference: <1280790637.14933.29.camel@ank32.eng.vmware.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'arch')
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index b9d1ff58844..227b0448960 100644
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c
@@ -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(void)
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;