Hi Reinette,
On 2/5/25 21:54, Reinette Chatre wrote:
> Hi Babu,
>
> subject: unassigm -> unassign
Sure.
>
> On 1/22/25 12:20 PM, Babu Moger wrote:
>> The mbm_cntr_assign mode provides a limited number of hardware counters
>
> (now back to "limited number of hardware counters")
How about?
The mbm_cntr_assign mode provides "num_mbm_cntrs" number of hardware counters
>
>> that can be assigned to an RMID, event pair to monitor bandwidth while
>> assigned. If all counters are in use, the kernel will show an error
>> message: "Out of MBM assignable counters" when a new assignment is
>> requested. To make space for a new assignment, users must unassign an
>
> To me "kernel will show an error" implies the kernel ring buffer. Please make
> the message accurate and mention that it will be in
> last_cmd_status while also considering to use -ENOSPC to help user space.
If all the counters are in use, the kernel will log 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.
>
>> already assigned counter and retry the assignment again..
>
> ".." -> "."
>
Sure.
>>
>> Add the functionality to unassign and free the counters in the domain.
>>
>> Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
>
> ...
>
>> diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
>> index 127c4000a81a..b6d188d0f9b7 100644
>> --- a/arch/x86/kernel/cpu/resctrl/monitor.c
>> +++ b/arch/x86/kernel/cpu/resctrl/monitor.c
>> @@ -1518,3 +1518,42 @@ int resctrl_assign_cntr_event(struct rdt_resource *r, struct rdt_mon_domain *d,
>>
>> return ret;
>> }
>> +
>> +/*
>> + * Unassign and free the counter if assigned else return success.
>> + */
>> +static int resctrl_free_config_cntr(struct rdt_resource *r, struct rdt_mon_domain *d,
>> + struct rdtgroup *rdtgrp, enum resctrl_event_id evtid)
>> +{
>> + int cntr_id, ret = 0;
>> +
>> + cntr_id = mbm_cntr_get(r, d, rdtgrp, evtid);
>> + if (cntr_id != -ENOENT) {
>
> This can be simplified and indent level reduced with:
>
> cntr_id = mbm_cntr_get(r, d, rdtgrp, evtid);
> if (cntr_id < 0)
> return ret;
>
Sure.
>> + ret = resctrl_config_cntr(r, d, evtid, rdtgrp->mon.rmid,
>> + rdtgrp->closid, cntr_id, false);
>> + if (!ret)
>> + mbm_cntr_free(d, cntr_id);
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +/*
>> + * Unassign a hardware counter associated with @evtid from the domain and
>> + * the group. Unassign the counters from all the domains if @d is NULL else
>> + * unassign from @d.
>> + */
>> +int resctrl_unassign_cntr_event(struct rdt_resource *r, struct rdt_mon_domain *d,
>> + struct rdtgroup *rdtgrp, enum resctrl_event_id evtid)
>> +{
>> + int ret = 0;
>> +
>> + if (!d) {
>> + list_for_each_entry(d, &r->mon_domains, hdr.list)
>> + ret = resctrl_free_config_cntr(r, d, rdtgrp, evtid);
>
> Same issue as previous patch wrt error handling.
Yes.
list_for_each_entry(d, &r->mon_domains, hdr.list) {
ret = resctrl_free_config_cntr(r, d, rdtgrp, evtid);
if (ret)
return ret;
}
>
>> + } else {
>> + ret = resctrl_free_config_cntr(r, d, rdtgrp, evtid);
>> + }
>> +
>> + return ret;
>> +}
>
> Reinette
>
--
Thanks
Babu Moger
