xref: /linux/tools/perf/Documentation/perf-iostat.txt (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
1perf-iostat(1)
2===============
3
4NAME
5----
6perf-iostat - Show I/O performance metrics
7
8SYNOPSIS
9--------
10[verse]
11'perf iostat' list
12'perf iostat' <ports> \-- <command> [<options>]
13
14DESCRIPTION
15-----------
16Mode 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
26OPTIONS
27-------
28<command>...::
29	Any command you can specify in a shell.
30
31list::
32	List all PCIe root ports.
33
34<ports>::
35	Select the root ports for monitoring. Comma-separated list is supported.
36
37EXAMPLES
38--------
39
401. 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
522. 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
713. 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
86SEE ALSO
87--------
88linkperf:perf-stat[1]
89