Commit 4980c176 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'x86_cache_for_6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 resctrl update from Dave Hansen:
 "Reduce redundant counter reads with resctrl refactoring"

* tag 'x86_cache_for_6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/resctrl: Avoid redundant counter read in __mon_event_count()
parents 682f7bba 322b72e0

arch/x86/kernel/cpu/resctrl/monitor.c

+19 −24
Original line number Diff line number Diff line
@@ -383,41 +383,36 @@ void free_rmid(u32 rmid) 
		list_add_tail(&entry->list, &rmid_free_lru);

}



static int __mon_event_count(u32 rmid, struct rmid_read *rr)

static struct mbm_state *get_mbm_state(struct rdt_domain *d, u32 rmid,

				       enum resctrl_event_id evtid)

{

	struct mbm_state *m;

	u64 tval = 0;



	if (rr->first)

		resctrl_arch_reset_rmid(rr->r, rr->d, rmid, rr->evtid);



	rr->err = resctrl_arch_rmid_read(rr->r, rr->d, rmid, rr->evtid, &tval);

	if (rr->err)

		return rr->err;



	switch (rr->evtid) {

	case QOS_L3_OCCUP_EVENT_ID:

		rr->val += tval;

		return 0;

	switch (evtid) {

	case QOS_L3_MBM_TOTAL_EVENT_ID:

		m = &rr->d->mbm_total[rmid];

		break;

		return &d->mbm_total[rmid];

	case QOS_L3_MBM_LOCAL_EVENT_ID:

		m = &rr->d->mbm_local[rmid];

		break;

		return &d->mbm_local[rmid];

	default:

		/*

		 * Code would never reach here because an invalid

		 * event id would fail in resctrl_arch_rmid_read().

		 */

		return -EINVAL;

		return NULL;

	}

}



static int __mon_event_count(u32 rmid, struct rmid_read *rr)

{

	struct mbm_state *m;

	u64 tval = 0;



	if (rr->first) {

		resctrl_arch_reset_rmid(rr->r, rr->d, rmid, rr->evtid);

		m = get_mbm_state(rr->d, rmid, rr->evtid);

		if (m)

			memset(m, 0, sizeof(struct mbm_state));

		return 0;

	}



	rr->err = resctrl_arch_rmid_read(rr->r, rr->d, rmid, rr->evtid, &tval);

	if (rr->err)

		return rr->err;



	rr->val += tval;



	return 0;