perf-iostat - Man Page

Show I/O performance metrics

Synopsis

perf iostat list
perf iostat <ports> -- <command> [<options>]

Description

Mode is intended to provide four I/O performance metrics per each PCIe root port:

Options

<command>...

Any command you can specify in a shell.

list

List all PCIe root ports.

<ports>

Select the root ports for monitoring. Comma-separated list is supported.

Examples

  1. List all PCIe root ports (example for 2-S platform):

    $ perf iostat list
    S0-uncore_iio_0<0000:00>
    S1-uncore_iio_0<0000:80>
    S0-uncore_iio_1<0000:17>
    S1-uncore_iio_1<0000:85>
    S0-uncore_iio_2<0000:3a>
    S1-uncore_iio_2<0000:ae>
    S0-uncore_iio_3<0000:5d>
    S1-uncore_iio_3<0000:d7>
  2. Collect metrics for all PCIe root ports:

    $ perf iostat -- dd if=/dev/zero of=/dev/nvme0n1 bs=1M oflag=direct
    357708+0 records in
    357707+0 records out
    375083606016 bytes (375 GB, 349 GiB) copied, 215.974 s, 1.7 GB/s
    Performance counter stats for 'system wide':
       port             Inbound Read(MB)    Inbound Write(MB)    Outbound Read(MB)   Outbound Write(MB)
    0000:00                    1                    0                    2                    3
    0000:80                    0                    0                    0                    0
    0000:17               352552                   43                    0                   21
    0000:85                    0                    0                    0                    0
    0000:3a                    3                    0                    0                    0
    0000:ae                    0                    0                    0                    0
    0000:5d                    0                    0                    0                    0
    0000:d7                    0                    0                    0                    0
  3. Collect metrics for comma-separated list of PCIe root ports:

    $ perf iostat 0000:17,0:3a -- dd if=/dev/zero of=/dev/nvme0n1 bs=1M oflag=direct
    357708+0 records in
    357707+0 records out
    375083606016 bytes (375 GB, 349 GiB) copied, 197.08 s, 1.9 GB/s
    Performance counter stats for 'system wide':
       port             Inbound Read(MB)    Inbound Write(MB)    Outbound Read(MB)   Outbound Write(MB)
    0000:17               358559                   44                    0                   22
    0000:3a                    3                    2                    0                    0
    197.081983474 seconds time elapsed

See Also

perf-stat(1)

Referenced By

perf(1).

09/26/2022 perf Manual