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Open Menu /external/cddl/dtracetoolkit/dist/Examples/sh_cpudist_example.txt 
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The following are examples of sh_cpudist.d.

This script traces the on-CPU time of Bourne shell functions and
prints a report containing distribution plots per function. Here it
traces the example program, Code/Shell/func_slow.sh.

   # sh_cpudist.d
   Tracing... Hit Ctrl-C to end.
   ^C
   
   On-CPU times (us),
   
      func_slow.sh, builtin, echo 
              value  ------------- Distribution ------------- count    
                  8 |                                         0        
                 16 |@@@@@@@@@@@@@                            1        
                 32 |@@@@@@@@@@@@@@@@@@@@@@@@@@@              2        
                 64 |                                         0        
   
      func_slow.sh, builtin, [ 
              value  ------------- Distribution ------------- count    
                  0 |                                         0        
                  1 |                                         1        
                  2 |                                         1        
                  4 |@                                        22       
                  8 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@   575      
                 16 |                                         2        
                 32 |                                         0        
                 64 |                                         2        
                128 |                                         0        
   
   Exclusive function on-CPU times (us),
   
      func_slow.sh, func, func_a 
              value  ------------- Distribution ------------- count    
              65536 |                                         0        
             131072 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 1        
             262144 |                                         0        
   
      func_slow.sh, func, func_b 
              value  ------------- Distribution ------------- count    
             262144 |                                         0        
             524288 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 1        
            1048576 |                                         0        
   
      func_slow.sh, func, func_c 
              value  ------------- Distribution ------------- count    
             524288 |                                         0        
            1048576 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 1        
            2097152 |                                         0        
   
   Inclusive function on-CPU times (us),
   
      func_slow.sh, func, func_b 
              value  ------------- Distribution ------------- count    
             524288 |                                         0        
            1048576 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 1        
            2097152 |                                         0        
   
      func_slow.sh, func, func_c 
              value  ------------- Distribution ------------- count    
             524288 |                                         0        
            1048576 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 1        
            2097152 |                                         0        
   
      func_slow.sh, func, func_a 
              value  ------------- Distribution ------------- count    
            1048576 |                                         0        
            2097152 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 1        
            4194304 |                                         0        

The on-CPU times should that the "[" builtin (test) usually took between 
8 and 15 microseconds to execute, and was called over 500 times.

The exclusive function on-CPU times show that func_a() spent between
131 ms and 262 ms on-CPU.

The inclusive function on-CPU times show that both func_b() and func_c()
spent between 1.0 and 2.1 seconds on-CPU, and func_a() spent between 2.1
and 4.2 seconds on-CPU. This inclusive time includes the time spent in other
functions called, and since func_a() called func_b() which called func_c(),
these times make sense.

These on-CPU times are the time the thread spent running on a CPU, from when
the function began to when it completed. This does not include time 
spent off-CPU time such as sleeping for I/O or waiting for scheduling.

On-CPU times are useful for showing who is causing the CPUs to be busy.
See Notes/ALLoncpu_notes.txt for more details. Also see
Notes/ALLexclusive_notes.txt and Notes/ALLinclusive_notes.txt for a
detailed explanation of exclusive vs inclusive function time.