Re: [PATCH v4 2/3] arm_mpam: resctrl: Add pass-through resctrl_arch_preconvert_bw()

[Ben Horgan <ben.horgan@arm.com>]

Hi Reinette,

On 7/6/26 22:33, Reinette Chatre wrote:
> Hi Ben,
> 
> On 7/6/26 9:06 AM, Ben Horgan wrote:
>> resctrl rounds up the percentage value of the MBA based on the bw_gran. As
>> MPAM uses a binary fixed point fraction format for MBA rather than a
>> decimal percentage, this introduces rounding errors.
>>
>> Without this additional rounding, if the user reads the value in an MB
>> schema and then writes it back to the schema, the value in hardware won't
>> change. However, with this additional rounding, this guarantee is broken
>> for systems with mbw_wd < 7.
>>
>> resctrl is introducing resctrl_arch_preconvert_bw() to allow the arch code
>> to specify the conversion resctrl does to the user-provided bandwidth
>> value. Add the MPAM version of resctrl_arch_preconvert_bw(). This does no
>> conversion.
>>
>> Signed-off-by: Ben Horgan <ben.horgan@arm.com>
>> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
>>
> 
> Unfortunately the "---" separator is missing here.

Another silly mistake.. sorry about that. I've corrected locally and
will send a respin in a day or two.

Thanks,

Ben

> 
>> Changes since v3:
>> Parameter order switch (Reinette)
>> Add Reinette's R-b
>> ---
> Reinette