====== Proc - Stat file ======

Miscellaneous kernel statistics in /proc/stat
-------------------------------------------------

Various pieces of miscellaneous information about kernel activity are available in the **/proc/stat** file.  All of the numbers reported in this file are aggregates since the system first booted.  For a quick look, simply cat the file:

<code bash>
cat /proc/stat

cpu  2255 34 2290 22625563 6290 127 456 0 0
cpu0 1132 34 1441 11311718 3675 127 438 0 0
cpu1 1123 0 849 11313845 2614 0 18 0 0
intr 114930548 113199788 3 0 5 263 0 4 [... lots more numbers ...]
ctxt 1990473
btime 1062191376
processes 2915
procs_running 1
procs_blocked 0
softirq 183433 0 21755 12 39 1137 231 21459 2263
</code>

The very first **cpu** line aggregates the numbers in all of the other "cpuN" lines.  These numbers identify the amount of time the CPU has spent performing different kinds of work.  Time units are in USER_HZ (typically hundredths of a second).  The meanings of the columns are as follows, from left to right:

  * **user**:  Normal processes executing in user mode.
  * **nice**:  Niced processes executing in user mode.
  * **system**:  Processes executing in kernel mode.
  * **idle**:  Twiddling thumbs.
  * **iowait**:  Waiting for I/O to complete.
  * **irq**:  Servicing interrupts.
  * **softirq**:  servicing softirqs.
  * **steal**:  Involuntary wait.
  * **guest**:  Running a normal guest.
  * **guest_nice**:  Running a niced guest.


The remaining lines are defined where:

  * **intr** gives counts of interrupts serviced since boot time, for each of the possible system interrupts.  The first column is the total of all interrupts serviced; each subsequent column is the total for that particular interrupt.
  * **ctxt** gives the total number of context switches across all CPUs.
  * **btime** gives the time at which the system booted, in seconds since the Unix epoch.
  * **processes** gives the number of processes and threads created, which includes (but is not limited to) those created by calls to the **fork()** and **clone()** system calls.
  * **procs_running** gives the total number of threads that are running or ready to run (i.e., the total number of runnable threads).
  * **procs_blocked** gives the number of  processes currently blocked, waiting for I/O to complete.
  * **softirq** gives counts of softirqs serviced since boot time, for each of the possible system softirqs. The first column is the total of all softirqs serviced; each subsequent column is the total for that particular softirq.