Re: [RFC PATCH v3 03/17] x86/resctrl: Detect Assignable Bandwidth Monitoring feature details

[Moger, Babu]

Hi Reinette,

On 5/9/2024 10:18 PM, Reinette Chatre wrote:
> Hi Babu,
>
> On 5/9/2024 3:34 PM, Moger, Babu wrote:
> > Hi Reinette,
> >
> > On 5/7/24 15:27, Reinette Chatre wrote:
> > > Hi Babu,
> > >
> > > On 5/6/2024 12:09 PM, Moger, Babu wrote:
> > > > On 5/3/24 18:26, Reinette Chatre wrote:
> > > > > On 3/28/2024 6:06 PM, Babu Moger wrote:
> > >
> > > ...
> > >
> > > > > > + * @mbm_assign_cntrs:	Maximum number of assignable counters
> > > > > >    */
> > > > > >   struct rdt_resource {
> > > > > >   	int			rid;
> > > > > > @@ -188,6 +198,8 @@ struct rdt_resource {
> > > > > >   	struct list_head	evt_list;
> > > > > >   	unsigned long		fflags;
> > > > > >   	bool			cdp_capable;
> > > > > > +	bool			mbm_assign_capable;
> > > > > > +	u32                     mbm_assign_cntrs;
> > > > > >   };
> > > > >
> > > > > Please check tabs vs spaces (in this whole series please).
> > > >
> > > > Sure. Will do.
> > > >
> > > > > I'm thinking that a new "MBM specific" struct within
> > > > > struct rdt_resource will be helpful to clearly separate the MBM related
> > > > > data. This will be similar to struct resctrl_cache for
> > > > > cache allocation and struct resctrl_membw for memory bandwidth
> > > > > allocation.
> > > >
> > > > Did you mean to move all the fields for monitoring to move to new struct?
> > > >
> > > > Struct resctrl_mbm {
> > > >            int                     num_rmid;
> > > >            bool                    mbm_assign_capable;
> > > >            u32                     mbm_assign_cntrs;
> > > > }:
> > >
> > > Indeed, so not actually MBM specific but monitoring specific as you state (with
> > > appropriate naming?). This is purely to help organize data within struct rdt_resource
> > > and (similar to struct resctrl_cache and struct resctrl_membw) not a new
> > > structure expected to be passed around. I think evt_list can also be a member.
> >
> > How about this?
> >
> > Lets keep assign_capable in main structure(like we have mon_capable) and
> > move rest of them into new structure.
> >
> > Struct resctrl_mon {
> >             int                     num_rmid;
> > 	   struct list_head        evt_list;
> >             u32                     num_assign_cntrs;
> > }:
>
> This looks like a good start. It certainly supports ABMC. I do not yet
> have a clear understanding about how this will support MPAM and soft-RMID/ABMC
> since the current implementation has an implicit scope of one counter per event per
> monitor group. It thus seem reasonable to have a new generic name of "cntrs".

How about renaming it to "assignable_counters"?

--
- Babu Moger