Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

The following is a demonstration of the sar-c.d script.


Here we run both sar-c.d and "sar -c 1 100" at the same time, to compare
outputs.

The DTrace script,

 # ./sar-c.d
 Time                 scall/s sread/s swrit/s  fork/s  exec/s  rchar/s  wchar/s
 2005 Jun 14 02:40:24    1556      82      71    0.00    0.00    10262    10508
 2005 Jun 14 02:40:25    1553      88      75    0.00    0.00    15095    15341
 2005 Jun 14 02:40:26    1596      89      76    0.00    0.00    14885    15131
 2005 Jun 14 02:40:27    5395     290     154    9.00   10.00   185991    77219
 2005 Jun 14 02:40:28    1755      91      98    1.00    1.00    15421    16788
 2005 Jun 14 02:40:29    1757     100      91    1.00    1.00    17127    17462
 2005 Jun 14 02:40:30    1603      95      80    0.00    0.00    16767    16634
 2005 Jun 14 02:40:31   14380      83    2420    1.00    1.00    14556   126461
 2005 Jun 14 02:40:32   10573      88    1586    0.00    0.00    14222    87888
 2005 Jun 14 02:40:33    1645      87      76    0.00    0.00    15320    15608
 2005 Jun 14 02:40:34    2099     167     130    0.00    0.00   126295    74281
 2005 Jun 14 02:40:35    1559      79      67    0.00    0.00    11663    11977
 [...]

The original command,

 $ sar -c 1 100
 
 SunOS jupiter 5.10 Generic i86pc    06/14/2005
 
 02:40:23 scall/s sread/s swrit/s  fork/s  exec/s rchar/s wchar/s
 02:40:24    1549      86      74    0.00    0.00   14799   15040
 02:40:25    1552      85      73    0.00    0.00   14475   14719
 02:40:26    5479     300     161    9.00   10.00  186755   77983
 02:40:27    1725      86      94    0.99    0.99   14819   16172
 02:40:28    1596      96      82    0.00    0.00   16521   16762
 02:40:29    1716      93      85    1.00    1.00   16395   16730
 02:40:30    1579      88      75    0.00    0.00   15324   15192
 02:40:32   23036      79    3887    0.99    0.99   10113  193520
 02:40:33    1756      94      83    0.00    0.00   14935   15300
 02:40:34    2099     165     130    0.00    0.00  125051   73552
 02:40:35    1560      82      69    0.00    0.00   15976   16287
 [...]

We can see that both tools are producing similar data.

The DTrace output lacks the "summary since boot" line, as it is not using
Kstat to fetch this data.


The sar-c.d script is not intended itself as a useful program, rather it
is intended as a starting point for other DTrace scripts; a starting point
of familiar statistics to provide the programmer with a "common ground"
of knowledge.