PSYoungGen gc log interpretation guideline

gistfile1.txt

# formatted (extra line breaks and spaces) for readability
45.152: [GC
    [PSYoungGen: |a|K -> |b|K (|c|K)]
    |d|K -> |e|K (|f|K), 0.1083183 secs]
    [Times: user=1.83 sys=0.01, real=0.11 secs]
    
Description:
PSYoungGen: Parallell Scavange Young Generation  
a:        Occupancy in young gen before minor gc   
b:        Occupancy in young gen after minor gc. Eden is empty => occupancy in survivor space (ie "survivor space occupancy")
c:        Total size of young gen (eden + the two survivor spaces)
d:        Cumalative occupancy of young and old gen before minor gc
e:        Cumalative occupancy of young and old gen after minor gc
f:        Total jvm heap size (young gen + old gen) 

Values that can be deduced:
Old gen heap size:                  f - c
X = Occupancy in old gen before gc: d - a
Y = Occupancy in old gen after gc:  e - b
Promotion to old gen:               Y - X  (0 confirms the "Minor GC Reclamation Principle")