Re: [PATCH 14/21] x86/intel_rdt/cqm: Add mon_data

[Shivappa Vikas]

On Sun, 2 Jul 2017, Thomas Gleixner wrote:

> On Mon, 26 Jun 2017, Vikas Shivappa wrote:
>
> > Add a mon_data directory for the root rdtgroup and all other rdtgroups.
> > The directory holds all of the monitored data for all domains and events
> > of all resources being monitored.
>
> Again. This does two things at once. Move the existing code to a new file
> and add the monitoring stuff. Please split it apart.

Will fix.

> > +static bool __mon_event_count(u32 rmid, struct rmid_read *rr)
> > +{
> > +	u64 tval;
> > +
> > +	tval = __rmid_read(rmid, rr->evtid);
> > +	if (tval & (RMID_VAL_ERROR | RMID_VAL_UNAVAIL)) {
> > +		rr->val = tval;
> > +		return false;
> > +	}
> > +	switch (rr->evtid) {
> > +	case QOS_L3_OCCUP_EVENT_ID:
> > +		rr->val += tval;
> > +		return true;
> > +	default:
> > +		return false;
>
> I have no idea what that return code means.

false for the invalid event id and all errors for __rmid_read. (IOW all errors 
for __mon_event-read)

> > +	}
> > +}
> > +
> > +void mon_event_count(void *info)
>
> Some explanation why this is a void pointer and how that function is called
> (I assume it's via IPI) would be appreciated.
>
> > +{
> > +	struct rdtgroup *rdtgrp, *entry;
> > +	struct rmid_read *rr = info;
> > +	struct list_head *llist;
>
>  *head;
>
> > +
> > +	rdtgrp = rr->rgrp;
> > +
> > +	if (!__mon_event_count(rdtgrp->rmid, rr))
> > +		return;
> > +
> > +	/*
> > +	 * For Ctrl groups read data from child monitor groups.
> > +	 */
> > +	llist = &rdtgrp->crdtgrp_list;
> > +
> > +	if (rdtgrp->type == RDTCTRL_GROUP) {
> > +		list_for_each_entry(entry, llist, crdtgrp_list) {
> > +			if (!__mon_event_count(entry->rmid, rr))
> > +				return;
> > +		}
> > +	}
> > +}
>
> > +static int get_rdt_resourceid(struct rdt_resource *r)
> > +{
> > +	if (r > (rdt_resources_all + RDT_NUM_RESOURCES - 1) ||
> > +	    r < rdt_resources_all ||
> > +	    ((r - rdt_resources_all) % sizeof(struct rdt_resource)))
> > +		return -EINVAL;
>
> If that ever happens, then you have other problems than a wrong pointer.
>
> > +
> > +	return ((r - rdt_resources_all) / sizeof(struct rdt_resource));
>
> Moo. Can't you simply put an index field into struct rdt_resource,
> intialize it with the resource ID and use that?

Ok will fix all above,

thanks,
Vikas

> Thanks,
>
> 	tglx