4. EXCEPTIONS › 4.3 Detailed Exception Descriptions › 02050: Percentage of Failed Logical Swaps Exceeds Max

02050: Percentage of Failed Logical Swaps Exceeds Max

FILE: Swapping Activity File
SAS FILE NAME: DAYS.SCPSWP01
SOURCE LOCATION: prefix.MICS.USER.SOURCE(DYRMFEXC)

SEVERITY: Impacting            (SEVERITY='I')
MANAGEMENT AREA: Performance   (MGMTAREA='PERFORMANCE')

PURPOSE:  Identify improper use of the logical swap facility.

RATIONALE:  An address space originally swapped logically
that later becomes physically swapped represents unnecessary
system overhead and an improper use of real storage.  While
logically swapped, an address space still occupies main
memory and the pages are not available for page stealing.  In
large TSO systems especially, this can represent megabytes of
real memory made unavailable by logically swapped users.
This situation could have been avoided if the address space
had been sent to physical swaps in the first place.

DEFINITION:  This exception is detected when the percentage
of all swaps, for this swap reason, that were originally
swapped logically and later were physically swapped to
auxiliary storage, exceeds an installation-specified maximum.

EXCEPTION STATEMENTS:  The SAS statements identifying the
exception situation and describing the condition are stored
in the source member named in SOURCE LOCATION and are
described below:

 /* ********************************************************
 **  02050 PERCENTAGE OF FAILED LOGICAL SWAPS EXCEEDS MAX **
 ******************************************************** */
PCT=((SWPLSWPS-SWPLSWPE)*100)/SWPTOSWP;
IF PCT GT percent
 THEN DO;
  EXCCODE='02050';SEVERITY='I';MGMTAREA='PERFORMANCE';
  EXCDESC1='PERCENTAGE OF FAILED LOGICAL SWAPS EXCEEDS MAX';
  EXCDESC2='FAILED LOG.  SWAPS=' !! PUT(PCT,5.1) !!
                   '%, REASON=' !! SWAPNAME;
  LINK HIT;
END;
THRESHOLD MODIFICATION:  The user should modify the percent
value according to the following convention:

percent - The percent of all swaps that were originally
swapped logically that eventually became physical swaps is
specified.  A threshold of 10 percent would appear as:

PCT GT 10