On 8/26/22 11:35, Reinette Chatre wrote:
> Hi Babu,
>
> On 8/26/2022 9:07 AM, Moger, Babu wrote:
>> On 8/24/22 16:15, Reinette Chatre wrote:
>>> On 8/22/2022 6:43 AM, Babu Moger wrote:
> ...
>
>>>> static int mkdir_mondata_subdir(struct kernfs_node *parent_kn,
>>>> struct rdt_domain *d,
>>>> struct rdt_resource *r, struct rdtgroup *prgrp)
>>>> @@ -2568,6 +2591,15 @@ static int mkdir_mondata_subdir(struct kernfs_node *parent_kn,
>>>> if (ret)
>>>> goto out_destroy;
>>>>
>>>> + /* Create the sysfs event configuration files */
>>>> + if (r->mon_configurable &&
>>>> + (mevt->evtid == QOS_L3_MBM_TOTAL_EVENT_ID ||
>>>> + mevt->evtid == QOS_L3_MBM_LOCAL_EVENT_ID)) {
>>>> + ret = mon_config_addfile(kn, mevt->config, priv.priv);
>>>> + if (ret)
>>>> + goto out_destroy;
>>>> + }
>>>> +
>>> This seems complex to have event features embedded in the code in this way. Could
>>> the events not be configured during system enumeration? For example, instead
>>> of hardcoding the config like above to always set:
>>>
>>> static struct mon_evt mbm_local_event = {
>>> .name = "mbm_local_bytes",
>>> .evtid = QOS_L3_MBM_LOCAL_EVENT_ID,
>>> + .config = "mbm_local_config",
>>>
>>>
>>> What if instead this information is dynamically set in rdt_get_mon_l3_config()? To
>>> make things simpler struct mon_evt could get a new member "configurable" and the
>>> events that actually support configuration will have this set only
>>> if system has X86_FEATURE_BMEC (struct rdt_resource->configurable then
>>> becomes unnecessary?). Being configurable thus becomes an event property, not
>>> a resource property. The "config" member introduced here could then be "config_name".
>>>
>>> I think doing so will also make this file creation simpler with a single
>>> mon_config_addfile() (possibly with more parameters) used to add both files to
>>> avoid the code duplication introduced by mon_config_addfile() above.
>>>
>>> What do you think?
>> Yes. We could do that. Something like this.
>>
>> struct mon_evt {
>> u32 evtid;
>> char *name;
>>
>> + bool configurable;
>>
>> char *config;
>> struct list_head list;
>> };
>>
>> Set the configurable if the system has X86_FEATURE_BMEC feature in
>> rdt_get_mon_l3_config.
> This would work (using bool in struct is something resctrl already do
> in many places). I also think that "config" should rather be named to
> "config_name" to make clear that it is not the actual configuration of
> the event.
Sure.
> Remember to update struct mon_evt's kerneldoc (I just noticed it is
> missing from this series).
Oh,, Will do.
Thanks
Babu
>
>> Create both files mbm_local_bytes and mbm_local_config in mon_addfile.
>>
>> Change the mon_addfile to pass mon_evt structure, so it have all
>> information to create both the files.
> Providing the structure to the function would make all the information
> available but I am not sure that doing so would make it easy to eliminate the
> duplicate code needed to create the other file. Giving more parameters
> to mon_addfile() is another option but it should be more clear to
> you as you write this code.
>
>> Then we can remove rdt_resource->configurable.
>>
>> Does that make sense?
>>
> Yes.
>
> Reinette
>
--
Thanks
Babu Moger
