Re: [PATCH v6 14/30] x86,fs/resctrl: Support binary fixed point event counters

[Fenghua Yu]

Hi, Tony,

On 6/26/25 09:49, Tony Luck wrote:
> Resctrl was written with the assumption that all monitor events can be
> displayed as unsigned decimal integers.
>
> Hardware architecture counters may provide some telemetry events with
> greater precision where the event is not a simple count, but is a
> measurement of some sort (e.g. Joules for energy consumed).
>
> Add a new argument to resctrl_enable_mon_event() for architecture code
> to inform the file system that the value for a counter is a fixed-point
> value with a specific number of binary places.  The file system will
> only allow architecture to use floating point format on events that it
> marked with mon_evt::is_floating_point.
>
> Fixed point values are displayed with values rounded to an appropriate
> number of decimal places for the precision of the number of binary places
> provided. In general one extra decimal place is added for every three
> additional binary places. There are some exceptions for low precision
> binary values where exact representation is possible:
>
>    1 binary place is 0.0 or 0.5.			=> 1 decimal place
>    2 binary places is 0.0. 0.25, 0.5, 0.75	=> 2 decimal places

nit. s/0.0./0.0,/

[SNIP]

Thanks.

-Fenghua