Re: [PATCH 19/21] x86/intel_rdt/mbm: Basic counting of MBM events (total and local)

From: Thomas Gleixner
Date: Fri Jul 07 2017 - 02:47:42 EST


On Thu, 6 Jul 2017, Shivappa Vikas wrote:
> On Sun, 2 Jul 2017, Thomas Gleixner wrote:
> > > INIT_LIST_HEAD(&r->evt_list);
> > >
> > > if (rdt_mon_features & (1 << QOS_L3_OCCUP_EVENT_ID))
> > > list_add_tail(&llc_occupancy_event.list, &r->evt_list);
> > > + if (is_mbm_total_enabled())
> > > + list_add_tail(&mbm_total_event.list, &r->evt_list);
> > > + if (is_mbm_local_enabled())
> > > + list_add_tail(&mbm_local_event.list, &r->evt_list);
> >
> > Confused. This hooks all monitoring features to RDT_RESOURCE_L3. Why?
>
> They are really L3 resource events as per the spec.
> CPUID.(EAX=0FH, ECX=0):EDX.L3[bit 1] = 1 if L3 monitoring and we query for all
> the llc_occupancy, l3 total and local b/w with the same resource id 1.

Then this should be documented somewhere in the code ....