Re: [RFC PATCH] x86:Use cpu_khz for loops_per_jiffy calculation

Ingo Molnar
2008-06-23T20:54:58Z

* Alok Kataria <akataria@vmware.com> wrote:

> Ok, I have changed the printks to KERN_INFO.
>
> On X86 platform we can use the value of tsc_khz computed during tsc
> calibration to calculate the loops_per_jiffy value. Its very important
> to keep the error in lpj values to minimum as any error in that may
> result in kernel panic in check_timer. In virtualization environment,
> On a highly overloaded host the guest delay calibration may sometimes
> result in errors beyond the ~50% that timer_irq_works can handle,
> resulting in the guest panicking.
>
> Does some formating changes to lpj_setup code to now have a single
> printk to print the bogomips value.
>
> We do this only for the boot processor because the AP's can have
> different base frequencies or the BIOS might boot a AP at a different
> frequency.

applied to tip/x86/delay - thanks Alok.

could you check whether tip/master (which now includes your changes as
well) works as expected in your test environment? I had to do a conflict
resolution in tsc_32.c, i hope i got it right. You can pick it up via:

http://people.redhat.com/mingo/tip.git/README

Ingo