Hi Reinette,
On 6/24/25 22:38, Reinette Chatre wrote:
> Hi Babu,
>
> On 6/13/25 2:05 PM, Babu Moger wrote:
>> The "mbm_event" mode offers "num_mbm_cntrs" number of counters that can be
>
> "The "mbm_event" mode" -> "The "mbm_event" counter assignment mode"?
Sure.
>
>> assigned to RMID, event pairs and monitor bandwidth usage as long as it is
>> assigned. If all the counters are in use, the kernel logs the error message
>> "Unable to allocate counter in domain" in
>> /sys/fs/resctrl/info/last_cmd_status when a new assignment is requested.
>>
>> To make space for a new assignment, users must unassign an already
>> assigned counter and retry the assignment again.
>>
>> Add the functionality to unassign and free the counters in the domain.
>>
>> Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
>> ---
> ...
>
>> ---
>> fs/resctrl/internal.h | 2 ++
>> fs/resctrl/monitor.c | 47 +++++++++++++++++++++++++++++++++++++++++++
>> 2 files changed, 49 insertions(+)
>>
>> diff --git a/fs/resctrl/internal.h b/fs/resctrl/internal.h
>> index 0767a1c46f26..4496c359ac22 100644
>> --- a/fs/resctrl/internal.h
>> +++ b/fs/resctrl/internal.h
>> @@ -388,6 +388,8 @@ int resctrl_find_cleanest_closid(void);
>>
>> int resctrl_assign_cntr_event(struct rdt_resource *r, struct rdt_mon_domain *d,
>> struct rdtgroup *rdtgrp, struct mon_evt *mevt);
>> +void resctrl_unassign_cntr_event(struct rdt_resource *r, struct rdt_mon_domain *d,
>> + struct rdtgroup *rdtgrp, struct mon_evt *mevt);
>>
>> #ifdef CONFIG_RESCTRL_FS_PSEUDO_LOCK
>> int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp);
>> diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c
>> index 38800fe45931..f2636aea6545 100644
>> --- a/fs/resctrl/monitor.c
>> +++ b/fs/resctrl/monitor.c
>> @@ -1016,6 +1016,14 @@ static int mbm_cntr_alloc(struct rdt_resource *r, struct rdt_mon_domain *d,
>> return -ENOSPC;
>> }
>>
>> +/**
>> + * mbm_cntr_free() - Clear the counter ID configuration details in the domain @d.
>> + */
>> +static void mbm_cntr_free(struct rdt_mon_domain *d, int cntr_id)
>> +{
>> + memset(&d->cntr_cfg[cntr_id], 0, sizeof(struct mbm_cntr_cfg));
>
> sizeof(struct mbm_cntr_cfg) -> sizeof(*d->cntr_cfg[0])
Sure. Changed it to.
memset(&d->cntr_cfg[cntr_id], 0, sizeof(*d->cntr_cfg));
>
>> +}
>> +
>> /**
>> * resctrl_alloc_config_cntr() - Allocate a counter ID and configure it for the
>> * event pointed to by @mevt and the resctrl group @rdtgrp within the domain @d.
>> @@ -1084,3 +1092,42 @@ int resctrl_assign_cntr_event(struct rdt_resource *r, struct rdt_mon_domain *d,
>>
>> return ret;
>> }
>> +
>> +/**
>> + * resctrl_free_config_cntr() - Unassign and reset the counter ID configuration
>> + * for the event pointed to by @mevt within the domain @d and resctrl group @rdtgrp.
>> + */
>> +static void resctrl_free_config_cntr(struct rdt_resource *r, struct rdt_mon_domain *d,
>> + struct rdtgroup *rdtgrp, struct mon_evt *mevt)
>> +{
>> + int cntr_id;
>> +
>> + cntr_id = mbm_cntr_get(r, d, rdtgrp, mevt->evtid);
>> +
>> + /* If there is no cntr_id assigned, nothing to do */
>> + if (cntr_id < 0)
>> + return;
>> +
>> + resctrl_config_cntr(r, d, mevt->evtid, rdtgrp->mon.rmid, rdtgrp->closid,
>> + cntr_id, false);
>> +
>> + mbm_cntr_free(d, cntr_id);
>> +
>> + return;
>
> No need for this return.
Sure.
>
>> +}
>> +
>> +/**
>> + * resctrl_unassign_cntr_event() - Unassign a hardware counter associated with
>> + * the event structure @mevt from the domain @d and the group @rdtgrp. Unassign
>> + * the counters from all the domains if @d is NULL else unassign from @d.
>> + */
>> +void resctrl_unassign_cntr_event(struct rdt_resource *r, struct rdt_mon_domain *d,
>> + struct rdtgroup *rdtgrp, struct mon_evt *mevt)
>> +{
>> + if (!d) {
>> + list_for_each_entry(d, &r->mon_domains, hdr.list)
>> + resctrl_free_config_cntr(r, d, rdtgrp, mevt);
>> + } else {
>> + resctrl_free_config_cntr(r, d, rdtgrp, mevt);
>> + }
>> +}
>
> Reinette
>
--
Thanks
Babu Moger
