perf-iostat(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXAMPLES | SEE ALSO | COLOPHON

PERF-IOSTAT(1)                 perf Manual                PERF-IOSTAT(1)

NAME         top

       perf-iostat - Show I/O performance metrics

SYNOPSIS         top

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

DESCRIPTION         top

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

       •   Inbound Read - I/O devices below root port read from the host
           memory, in MB

       •   Inbound Write - I/O devices below root port write to the host
           memory, in MB

       •   Outbound Read - CPU reads from I/O devices below root port,
           in MB

       •   Outbound Write - CPU writes to I/O devices below root port,
           in MB

OPTIONS         top

       <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         top

        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         top

       perf-stat(1)

COLOPHON         top

       This page is part of the perf (Performance analysis tools for
       Linux (in Linux source tree)) project.  Information about the
       project can be found at 
       ⟨https://perf.wiki.kernel.org/index.php/Main_Page⟩.  If you have a
       bug report for this manual page, send it to
       linux-kernel@vger.kernel.org.  This page was obtained from the
       project's upstream Git repository
       ⟨http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git⟩
       on 2021-08-27.  (At that time, the date of the most recent commit
       that was found in the repository was 2021-08-26.)  If you
       discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for
       the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original
       manual page), send a mail to man-pages@man7.org

perf                           2021-04-20                 PERF-IOSTAT(1)