Re: [PATCH v9 3/9] x86/resctrl: Modify update_mba_bw() to use per ctrl_mon group event

Moger, Babu
2024-11-15T16:21:10Z

Hi Tony,

On 11/13/2024 6:17 PM, Tony Luck wrote:
> Instead of hard-coding the memory bandwidth local event as the
> input to the mba_sc feedback look, use the event that the user
> configured for each ctrl_mon group.
>
> Signed-off-by: Tony Luck <tony.luck@intel.com>
> ---
> arch/x86/kernel/cpu/resctrl/monitor.c | 23 ++++++++++++++++++-----
> 1 file changed, 18 insertions(+), 5 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
> index 7ef1a293cc13..2176e355e864 100644
> --- a/arch/x86/kernel/cpu/resctrl/monitor.c
> +++ b/arch/x86/kernel/cpu/resctrl/monitor.c
> @@ -752,20 +752,31 @@ static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_mon_domain *dom_mbm)
> u32 closid, rmid, cur_msr_val, new_msr_val;
> struct mbm_state *pmbm_data, *cmbm_data;
> struct rdt_ctrl_domain *dom_mba;
> + enum resctrl_event_id evt_id;
> struct rdt_resource *r_mba;
> - u32 cur_bw, user_bw, idx;
> struct list_head *head;
> struct rdtgroup *entry;
> + u32 cur_bw, user_bw;
>
> - if (!is_mbm_local_enabled())
> + if (!is_mbm_enabled())
> return;
>
> r_mba = &rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl;
> + evt_id = rgrp->mba_mbps_event;
> +
> + if (WARN_ON_ONCE(!is_mbm_event(evt_id)))
> + return;

I feel this check is enough.

> + if (WARN_ON_ONCE(evt_id == QOS_L3_MBM_LOCAL_EVENT_ID && !is_mbm_local_enabled()))
> + return;
> + if (WARN_ON_ONCE(evt_id == QOS_L3_MBM_TOTAL_EVENT_ID && !is_mbm_total_enabled()))
> + return;

These two checks are not necessary. You are already validating it while
initializing(in patch 7).

> +
>
> closid = rgrp->closid;
> rmid = rgrp->mon.rmid;
> - idx = resctrl_arch_rmid_idx_encode(closid, rmid);
> - pmbm_data = &dom_mbm->mbm_local[idx];
> + pmbm_data = get_mbm_state(dom_mbm, closid, rmid, evt_id);
> + if (WARN_ON_ONCE(!pmbm_data))
> + return;
>
> dom_mba = get_ctrl_domain_from_cpu(smp_processor_id(), r_mba);
> if (!dom_mba) {
> @@ -784,7 +795,9 @@ static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_mon_domain *dom_mbm)
> */
> head = &rgrp->mon.crdtgrp_list;
> list_for_each_entry(entry, head, mon.crdtgrp_list) {
> - cmbm_data = &dom_mbm->mbm_local[entry->mon.rmid];
> + cmbm_data = get_mbm_state(dom_mbm, entry->closid, entry->mon.rmid, evt_id);
> + if (WARN_ON_ONCE(!cmbm_data))
> + return;
> cur_bw += cmbm_data->prev_bw;
> }
>

--
- Babu Moger