function module vs loacal subroutines

[Former Member]

Hi all,

I have created some six function modules for data migration.all are working fine.

but if i utillized local subroutine for the same logic

it creates performance issue.actually performance for the local subroutine is far better than (1/12) than function module.i checked all coding in both routines .everything is correct.

then what could be the problem.if u know the answer please let me know.

regards,

raja

[naimesh_patel]

Hello,

Whenever you use any FM, system allocates the memory for all the FMs in that function group. SO, it may be the reason for slow access.

Regards,

Naimesh

[Former Member]

While using subroutines

the whole of program code is loaded in to memory

but while using function modules

only when the call happends the FM and its group is loaded in to memory

that could be a reason for performance drop..

use SE30 and try analysing the code for performance u will get to know

Harish

[Former Member]

Hi,

Whenever a function module is called there is a process called context switch happens in micro-processor.

In this process all the registers(local memory of microprocessor ), program counter and memory(here cache and RAM) is refreshed and reloaded and previous content is saved in memory location. This whole process takes time. Thats why we have performance issue here.

So direct line of code is faster that local sub-routine . and local sub-routine is faster than function module.

Regards,

Sumit.