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