[PATCH v2] perf stat: Enable iostat mode for HiSilicon PCIe PMU

[Namhyung Kim]

Hello,

On Wed, Feb 7, 2024 at 7:29 PM Yicong Yang <yangyicong at huawei.com> wrote:
>
> From: Yicong Yang <yangyicong at hisilicon.com>
>
> Some HiSilicon platforms provide PCIe PMU devices for monitoring the
> throughput and latency of PCIe traffic. With the support of PCIe PMU
> we can enable the perf iostat mode.

Hmm.. so it only works for HiSilicon.  What if users run it on a different
platform?  I think ARM should care about this.

Thanks,
Namhyung


>
> The HiSilicon PCIe PMU can support measuring the throughput of certain
> TLP types and of certain root port. Totally 6 metrics are provided in
> the unit of MB:
>
> - Inbound MWR: The memory write TLPs from the devices downstream the root port
> - Inbound MRD: The memory read TLPs from the devices downstream the root port
> - Inbound CPL: The completion TLPs from the devices downstream the root port
> - Outbound MWR: The memory write TLPs from the CPU to the downstream devices
> - Outbound MRD: The memory read TLPs from the CPU to the downstream devices
> - Outbound CPL: The completions TLPs from the CPU to the downstream devices
>
> Since the PMU measures the throughput in DWords. So we need to calculate
> the throughput in MB like:
>   Count * 4B / 1024 / 1024
>
> Some of the display of the `perf iostat` will be like:
> [root at localhost tmp]# ./perf iostat list
> hisi_pcie0_core2<0000:40:00.0>
> hisi_pcie2_core2<0000:5f:00.0>
> hisi_pcie0_core1<0000:16:00.0>
> hisi_pcie0_core1<0000:16:04.0>
> [root at localhost tmp]# ./perf iostat --timeout 10000
>
>  Performance counter stats for 'system wide':
>
>     port              Inbound MWR(MB)      Inbound MRD(MB)      Inbound CPL(MB)     Outbound MWR(MB)     Outbound MRD(MB)     Outbound CPL(MB)
> 0000:40:00.0                    0                    0                    0                    0                    0                    0
> 0000:5f:00.0                    0                    0                    0                    0                    0                    0
> 0000:16:00.0             16272.99               366.58                    0                15.09                    0             16156.85
> 0000:16:04.0                    0                    0                    0                    0                    0                    0
>
>       10.008227512 seconds time elapsed
>
> [root at localhost tmp]# ./perf iostat 0000:16:00.0 -- fio -name=read
> -numjobs=30 -filename=/dev/nvme0n1 -rw=rw -iodepth=128 -direct=1 -sync=0
> -norandommap -group_reporting -runtime=10 -time_based -bs=64k
>
>  Performance counter stats for 'system wide':
>
>     port              Inbound MWR(MB)      Inbound MRD(MB)      Inbound CPL(MB)     Outbound MWR(MB)     Outbound MRD(MB)     Outbound CPL(MB)
> 0000:40:00.0                    0                    0                    0                    0                    0                    0
> 0000:5f:00.0                    0                    0                    0                    0                    0                    0
> 0000:16:00.0             16314.30               371.22                    0                15.21                    0             16362.20
> 0000:16:04.0                    0                    0                    0                    0                    0                    0
>
>       10.168561767 seconds time elapsed
>
>        0.465373000 seconds user
>        1.952948000 seconds sys
>
> More information of the HiSilicon PCIe PMU can be found at
> Documentation/admin-guide/perf/hisi-pcie-pmu.rst.
>
> Signed-off-by: Yicong Yang <yangyicong at hisilicon.com>