Re: [PATCH v3 1/3] arch, x86, tsc deadline clockevent dev: reduce frequency roundoff error

[Paolo Bonzini]

On 13/07/2016 15:49, Peter Zijlstra wrote:
> On Wed, Jul 13, 2016 at 03:03:42PM +0200, Nicolai Stange wrote:
> 
>>              clockevents_config_and_register(levt,
>> +                                            (u32)(((u64)tsc_khz * 1000) /
>> +                                                    TSC_DIVISOR),
>>                                              0xF, ~0UL);
> 
> div_u64() perhaps ?

Or just squash together the two patches and do

        tsc_khz * (1000 / TSC_DIVISOR)

because with TSC_DIVISOR equal to 2/4/8 there is no error from
reassociating the operation.

Paolo