# perf-iostat

## NAME



           perf-iostat - 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:
    
           •   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



           <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
    


* * *