Kbase 726: Interpreting OVL Statistics in the Progress Log file (-ovl)
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
5/10/1998 |
|
Interpreting OVL Statistics in the Progress Log file (-ovl)
900123-slk01The OVL Statistics in the Progress Log file: Customers using the -ovl
parameter (i.e., using the memory saver version) will see the
following messages written to the log file: *** DCL Statistics:
Overlay Faults: 1000 Return Faults: 100
OVL Buffer Size: 132564 OVL Buffer Fills: 3
OVL Buffer Used: 97888 These statistics are primarily used to
determine (with trial-and-error) the performance of the overlay
parameter being used. Here is an explanation of the entries: Overlay
Faults = the number of times a "chunk" had to be read in from the .ovl
file. Return Faults = the number of times a "chunk" was swapped out
and it was a function that was in the return stack. Example: Stack
Trace: _A, _B, _C, _D, _E. Assume all the functions on the stack are
"chunks" (located in the .ovl file). If the swapping in of function E
causes function B to be swapped out - this is a return fault. OVL
buffer Size = size of the overlay area. OVL buffer fills = the total
number of times the overlay area was filled during a session. OVL
Buffer used = on the last fill of the overlay area, this represents
the high water mark for the fill. How to use the statistics: If the
number of return faults per overlay faults is greater than 15%, the
overlay buffer size is too small. if a small but significant change in
the OVL buffer size causes a large change in the overlay faults, the
OVL buffer size should be modified to reflect the lower number of
overlay faults.
Progress Software Technical Support Note # 726