On 2010-08-12 02:00 +0200, Greg KH wrote:
quoted text > 2.6.34-stable review patch. If anyone has any objections, please let us know.
Sorry for being a bit late -- I didn't get around to build 2.6.34.4-rc1
in time. :-(
quoted text > From: Alok Kataria <akataria@vmware.com>
>
> 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>
>
> ---
> arch/x86/kernel/cpu/vmware.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> --- 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(
> 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);
This led to a build failure for me because HZ is not defined in the
attached configuration. Note that this problem did not show up in
2.6.35.2 with a very similar .config file.
quoted text > + preset_lpj = lpj;
> + }
> +
> return tsc_hz;
> }
Regards,
Sven
