Hi Reinette,
On Thu, May 11, 2023 at 11:40 PM Reinette Chatre reinette.chatre@intel.com wrote:
On 4/21/2023 7:17 AM, Peter Newman wrote:
list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
mbm_update(r, d, prgrp->mon.rmid);
/** mbm_update() on every RMID would result in excessive IPIs* when RMIDs are soft.*/if (!rdt_mon_soft_rmid) {mbm_update(r, d, prgrp->mon.rmid);
head = &prgrp->mon.crdtgrp_list;list_for_each_entry(crgrp, head, mon.crdtgrp_list)mbm_update(r, d, crgrp->mon.rmid);
head = &prgrp->mon.crdtgrp_list;list_for_each_entry(crgrp, head, mon.crdtgrp_list)mbm_update(r, d, crgrp->mon.rmid);} if (is_mba_sc(NULL)) update_mba_bw(prgrp, d);hmmm ... I think that update_mba_bw() relies on mbm_update() to call mbm_bw_count() to update the data it depends on. Keeping update_mba_bw() while dropping mbm_update() thus seems problematic. AMD does not support the software controller though so it may make things simpler if support for software RMIDs disables support for software controller (in a clear way).
I looked over this again and realized that the rationale for skipping mbm_update() in this patch is incorrect. __mon_event_count_soft_rmid() does not send any IPIs, so it's perfectly fine to call mbm_update() and update_mba_bw() when using soft RMIDs.
Even if we don't use the software controller on AMD, it seems conceptually cleaner to just allow soft and hard RMIDs to be used interchangeably wherever they work.
-Peter