Re: Concatination order in STEPLIB

Raja Easwaramoorthy wrote:
I found that CPU time varies when I change the concatenation order of loadlibs in STEPLIB. For example, when I had CEE.SCREEN loadlib in the first; before application programs loadlib, the CPU took only 0.6 seconds but when I had application loadlib in the first; before CEE.SCREEN, the CPU took 1.2 seconds.
Run 1 - In this case CPU took only 0.6 seconds to execute the job
-----
//STEPLIB DD DSN=CEE.SCREEN,DISP=SHR
// DD DSN=S1222.SYS.LOADLIB,DISP=SHR
Run 2 - In this case CPU took 1.2 seconds to execute the job
-----
//STEPLIB DD DSN=S1222.SYS.LOADLIB,DISP=SHR
// DD DSN=CEE.SCREEN,DISP=SHR
Does anyone know why there is a difference in CPU time when I change the concatenation order of loadlibs in STEPLIB?

Obviously, the load module you are requesting exists in CEE.SCREEN
but does not exist in S1222.SYS.LOADLIB (which is probably much
larger). When you specify the correct PDS first, the load module
is found, and the search stops. When you specify the wrong PDS first,
the job scheduler has to search through the wrong PDS before it
can get to the right one.

If you know where the module is, why specify any other PDS?

/ Lars Poulsen
.

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