Hi,
On Wed, Aug 18, 2021 at 01:12:46PM +0800, Qi Liu wrote:
> PCIe PMU Root Complex Integrated End Point(RCiEP) device is supported
> to sample bandwidth, latency, buffer occupation etc.
>
> Each PMU RCiEP device monitors multiple Root Ports, and each RCiEP is
> registered as a PMU in /sys/bus/event_source/devices, so users can
> select target PMU, and use filter to do further sets.
>
> Filtering options contains:
> event - select the event.
> port - select target Root Ports. Information of Root Ports are
> shown under sysfs.
> bdf - select requester_id of target EP device.
> trig_len - set trigger condition for starting event statistics.
> trig_mode - set trigger mode. 0 means starting to statistic when bigger
> than trigger condition, and 1 means smaller.
> thr_len - set threshold for statistics.
> thr_mode - set threshold mode. 0 means count when bigger than threshold,
> and 1 means smaller.
I think this is getting there now, thanks for sticking with it. Just a
couple of comments below..
> +static bool hisi_pcie_pmu_validate_event_group(struct perf_event *event)
> +{
> + struct perf_event *sibling, *leader = event->group_leader;
> + int counters = 1;
> +
> + if (!is_software_event(leader)) {
> + if (leader->pmu != event->pmu)
> + return false;
> +
> + if (leader != event)
> + counters++;
> + }
> +
> + for_each_sibling_event(sibling, event->group_leader) {
> + if (is_software_event(sibling))
> + continue;
> +
> + if (sibling->pmu != event->pmu)
> + return false;
> +
> + counters++;
> + }
> +
> + return counters <= HISI_PCIE_MAX_COUNTERS;
> +}
Given that this function doesn't look at the event numbers, doesn't this
over-provision the counter registers? For example, if I create a group
containing 4 of the same event, then we'll allocate four counters but only
use one. Similarly, if I create a group containing two events, one for the
normal counter and one for the extended counter, then we'll again allocate
two counters instead of one.
Have I misunderstood?
> +static int hisi_pcie_pmu_event_init(struct perf_event *event)
> +{
> + struct hisi_pcie_pmu *pcie_pmu = to_pcie_pmu(event->pmu);
> + struct hw_perf_event *hwc = &event->hw;
> +
> + event->cpu = pcie_pmu->on_cpu;
> +
> + if (EXT_COUNTER_IS_USED(hisi_pcie_get_event(event)))
> + hwc->event_base = HISI_PCIE_EXT_CNT;
> + else
> + hwc->event_base = HISI_PCIE_CNT;
> +
> + if (event->attr.type != event->pmu->type)
> + return -ENOENT;
> +
> + /* Sampling is not supported. */
> + if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
> + return -EOPNOTSUPP;
> +
> + if (!hisi_pcie_pmu_valid_filter(event, pcie_pmu)) {
> + pci_err(pcie_pmu->pdev, "Invalid filter!\n");
Please remove this message, as it's triggerable from userspace.
Will
