tools/perf/Documentation/perf-iostat.txt

   1 perf-iostat(1)
   2 ===============
   3
   4 NAME
   5 ----
   6 perf-iostat - Show I/O performance metrics
   7
   8 SYNOPSIS
   9 --------
  10 [verse]
  11 'perf iostat' list
  12 'perf iostat' <ports> \-- <command> [<options>]
  13
  14 DESCRIPTION
  15 -----------
  16 Mode is intended to provide four I/O performance metrics per each PCIe root port:
  17
  18 - Inbound Read   - I/O devices below root port read from the host memory, in MB
  19
  20 - Inbound Write  - I/O devices below root port write to the host memory, in MB
  21
  22 - Outbound Read  - CPU reads from I/O devices below root port, in MB
  23
  24 - Outbound Write - CPU writes to I/O devices below root port, in MB
  25
  26 OPTIONS
  27 -------
  28 <command>...::
  29         Any command you can specify in a shell.
  30
  31 list::
  32         List all PCIe root ports.
  33
  34 <ports>::
  35         Select the root ports for monitoring. Comma-separated list is supported.
  36
  37 EXAMPLES
  38 --------
  39
  40 1. List all PCIe root ports (example for 2-S platform):
  41
  42    $ perf iostat list
  43    S0-uncore_iio_0<0000:00>
  44    S1-uncore_iio_0<0000:80>
  45    S0-uncore_iio_1<0000:17>
  46    S1-uncore_iio_1<0000:85>
  47    S0-uncore_iio_2<0000:3a>
  48    S1-uncore_iio_2<0000:ae>
  49    S0-uncore_iio_3<0000:5d>
  50    S1-uncore_iio_3<0000:d7>
  51
  52 2. Collect metrics for all PCIe root ports:
  53
  54    $ perf iostat -- dd if=/dev/zero of=/dev/nvme0n1 bs=1M oflag=direct
  55    357708+0 records in
  56    357707+0 records out
  57    375083606016 bytes (375 GB, 349 GiB) copied, 215.974 s, 1.7 GB/s
  58
  59     Performance counter stats for 'system wide':
  60
  61       port             Inbound Read(MB)    Inbound Write(MB)    Outbound Read(MB)   Outbound Write(MB)
  62    0000:00                    1                    0                    2                    3
  63    0000:80                    0                    0                    0                    0
  64    0000:17               352552                   43                    0                   21
  65    0000:85                    0                    0                    0                    0
  66    0000:3a                    3                    0                    0                    0
  67    0000:ae                    0                    0                    0                    0
  68    0000:5d                    0                    0                    0                    0
  69    0000:d7                    0                    0                    0                    0
  70
  71 3. Collect metrics for comma-separated list of PCIe root ports:
  72
  73    $ perf iostat 0000:17,0:3a -- dd if=/dev/zero of=/dev/nvme0n1 bs=1M oflag=direct
  74    357708+0 records in
  75    357707+0 records out
  76    375083606016 bytes (375 GB, 349 GiB) copied, 197.08 s, 1.9 GB/s
  77
  78     Performance counter stats for 'system wide':
  79
  80       port             Inbound Read(MB)    Inbound Write(MB)    Outbound Read(MB)   Outbound Write(MB)
  81    0000:17               358559                   44                    0                   22
  82    0000:3a                    3                    2                    0                    0
  83
  84         197.081983474 seconds time elapsed
  85
  86 SEE ALSO
  87 --------
  88 linkperf:perf-stat[1]