/proc/stat

Internal

• Linux CPU Info
• The /proc filesystem

/proc/stat

             kernel/system statistics.  Varies with architecture.  Common
             entries include:

             cpu  3357 0 4313 1362393
                    The amount of time, measured in units of USER_HZ
                    (1/100ths of a second on most architectures, use
                    sysconf(_SC_CLK_TCK) to obtain the right value), that
                    the system spent in various states:

                    user   (1) Time spent in user mode.

                    nice   (2) Time spent in user mode with low priority
                           (nice).

                    system (3) Time spent in system mode.

                    idle   (4) Time spent in the idle task.  This value
                           should be USER_HZ times the second entry in the
                           /proc/uptime pseudo-file.

                    iowait (since Linux 2.5.41)
                           (5) Time waiting for I/O to complete.  This
                           value is not reliable, for the following
                           reasons:

                           1. The CPU will not wait for I/O to complete;
                              iowait is the time that a task is waiting for
                              I/O to complete.  When a CPU goes into idle
                              state for outstanding task I/O, another task
                              will be scheduled on this CPU.

                           2. On a multi-core CPU, the task waiting for I/O
                              to complete is not running on any CPU, so the
                              iowait of each CPU is difficult to calculate.

                           3. The value in this field may decrease in
                              certain conditions.

                           irq (since Linux 2.6.0-test4)
                              (6) Time servicing interrupts.

                           softirq (since Linux 2.6.0-test4)
                              (7) Time servicing softirqs.

                           steal (since Linux 2.6.11)
                              (8) Stolen time, which is the time spent in
                              other operating systems when running in a
                              virtualized environment

                           guest (since Linux 2.6.24)
                              (9) Time spent running a virtual CPU for
                              guest operating systems under the control of
                              the Linux kernel.

                           guest_nice (since Linux 2.6.33)
                              (10) Time spent running a niced guest
                              (virtual CPU for guest operating systems
                              under the control of the Linux kernel).

                    page 5741 1808
                           The number of pages the system paged in and the
                           number that were paged out (from disk).

                    swap 1 0
                           The number of swap pages that have been brought
                           in and out.

                    intr 1462898
                           This line shows counts of interrupts serviced
                           since boot time, for each of the possible system
                           interrupts.  The first column is the total of
                           all interrupts serviced including unnumbered
                           architecture specific interrupts; each
                           subsequent column is the total for that
                           particular numbered interrupt.  Unnumbered
                           interrupts are not shown, only summed into the
                           total.

                    disk_io: (2,0):(31,30,5764,1,2) (3,0):...
                           (major,disk_idx):(noinfo, read_io_ops,
                           blks_read, write_io_ops, blks_written)
                           (Linux 2.4 only)

                    ctxt 115315
                           The number of context switches that the system
                           underwent.

                    btime 769041601
                           boot time, in seconds since the Epoch,
                           1970-01-01 00:00:00 +0000 (UTC).

                    processes 86031
                           Number of forks since boot.

                    procs_running 6
                           Number of processes in runnable state.  (Linux
                           2.5.45 onward.)

                    procs_blocked 2
                           Number of processes blocked waiting for I/O to
                           complete.  (Linux 2.5.45 onward.)