Mastering pidstat: Monitor CPU, Memory, and I/O of Linux Processes

pidstat command monitors all processes' status, such as CPU, memory, and I/O usage.

It can specify a particular process ID, monitoring interval, and other options.

Running pidstat without arguments displays CPU-related statistics for all processes.

Column meanings

PID : Process ID

%usr : Percentage of CPU time spent in user mode

%system : Percentage of CPU time spent in kernel mode

%CPU : Overall CPU usage of the process

CPU : CPU number on which the process is running

Command : Command name of the task

Usage examples

1. CPU usage statistics

# pidstat -u

Displays the same result as the default output.

2. Memory usage statistics

# pidstat -r

Field meanings:

minflt/s, majflt/s : Number of page faults per second when virtual memory is mapped to physical memory

VSZ : Virtual memory size of the process (kB)

RSS : Resident set size (physical memory) of the process (kB)

%MEM : Percentage of memory used by the process

3. I/O usage statistics

# pidstat -d

Field meanings:

kB_rd/s : Kilobytes read from disk per second by the process

kB_wr/s : Kilobytes written to disk per second by the process

4. Combined statistics

# pidstat -urd -h

Shows CPU, memory, and I/O data for each process; the -h option displays all information in a single line.

5. Statistics for a specific process

# pidstat -urd -p 1 -h

The -p 1 option specifies that data for the process with ID 1 should be reported.

6. Statistics for all child processes of a command

# pidstat -T CHILD -C mysql

The -T option selects the type of statistics, and -C specifies the command name. This command reports information for all child processes of the mysql command.