Re: [PATCH v2 1/1] dmaengine: idxd: Add IDXD performance monitor support

[Zanussi, Tom]

Hi Vinod,

On 4/20/2021 6:11 AM, Vinod Koul wrote:
> On 03-04-21, 11:45, Tom Zanussi wrote:
>
> > +config INTEL_IDXD_PERFMON
> > +	bool "Intel Data Accelerators performance monitor support"
> > +	depends on INTEL_IDXD
> > +	default y
>
> default y..?

Will change to n.

> >   /* IDXD software descriptor */
> > @@ -369,4 +399,19 @@ int idxd_cdev_get_major(struct idxd_device *idxd);
> >   int idxd_wq_add_cdev(struct idxd_wq *wq);
> >   void idxd_wq_del_cdev(struct idxd_wq *wq);
> >   
> > +/* perfmon */
> > +#ifdef CONFIG_INTEL_IDXD_PERFMON
>
> maybe use IS_ENABLED()
>
> > @@ -556,6 +562,8 @@ static int __init idxd_init_module(void)
> >   	for (i = 0; i < IDXD_TYPE_MAX; i++)
> >   		idr_init(&idxd_idrs[i]);
> >   
> > +	perfmon_init();
> > +
> >   	err = idxd_register_bus_type();
> >   	if (err < 0)
> >   		return err;
> > @@ -589,5 +597,6 @@ static void __exit idxd_exit_module(void)
> >   	pci_unregister_driver(&idxd_pci_driver);
> >   	idxd_cdev_remove();
> >   	idxd_unregister_bus_type();
> > +	perfmon_exit();
>
> Ideally would make sense to add perfmon module first and then add use in
> idxd..

OK, I'll separate this out into a separate patch.

> > +static ssize_t cpumask_show(struct device *dev, struct device_attribute *attr,
> > +			    char *buf);
> > +
> > +static cpumask_t		perfmon_dsa_cpu_mask;
> > +static bool			cpuhp_set_up;
> > +static enum cpuhp_state		cpuhp_slot;
> > +
> > +static DEVICE_ATTR_RO(cpumask);
>
> Pls document these new attributes added
>
> > +static int perfmon_collect_events(struct idxd_pmu *idxd_pmu,
> > +				  struct perf_event *leader,
> > +				  bool dogrp)
>
> dogrp..?

Yeah, bad name, first thought on seeing it is always 'dog'. ;-)

> > +static int perfmon_validate_group(struct idxd_pmu *pmu,
> > +				  struct perf_event *event)
> > +{
> > +	struct perf_event *leader = event->group_leader;
> > +	struct idxd_pmu *fake_pmu;
> > +	int i, ret = 0, n;
> > +
> > +	fake_pmu = kzalloc(sizeof(*fake_pmu), GFP_KERNEL);
> > +	if (!fake_pmu)
> > +		return -ENOMEM;
> > +
> > +	fake_pmu->pmu.name = pmu->pmu.name;
> > +	fake_pmu->n_counters = pmu->n_counters;
> > +
> > +	n = perfmon_collect_events(fake_pmu, leader, true);
> > +	if (n < 0) {
> > +		ret = n;
> > +		goto out;
> > +	}
> > +
> > +	fake_pmu->n_events = n;
> > +	n = perfmon_collect_events(fake_pmu, event, false);
> > +	if (n < 0) {
> > +		ret = n;
> > +		goto out;
> > +	}
> > +
> > +	fake_pmu->n_events = n;
> > +
> > +	for (i = 0; i < n; i++) {
> > +		int idx;
>
> lets move it to top of the function please
>
> > +static inline u64 perfmon_pmu_read_counter(struct perf_event *event)
> > +{
> > +	struct hw_perf_event *hwc = &event->hw;
> > +	struct idxd_device *idxd;
> > +	int cntr = hwc->idx;
> > +	u64 cntrdata;
> > +
> > +	idxd = event_to_idxd(event);
> > +
> > +	cntrdata = ioread64(CNTRDATA_REG(idxd, cntr));
> > +
> > +	return cntrdata;
>
> return ioread64() ?

Yeah, I removed some intervening code and didn't change this, will do.

Thanks for reviewing this,

Tom