high load

[laddu]

Code:

top - 19:33:33 up 1 day,  4:20,  2 users,  load average: 13.03, 5.36, 6.31
Tasks: 265 total,   1 running, 264 sleeping,   0 stopped,   0 zombie
Cpu(s):  0.0%us,  1.7%sy,  0.0%ni,  6.6%id, 91.5%wa,  0.1%hi,  0.2%si,  0.0%st
Mem:   2074936k total,  2021580k used,    53356k free,     3640k buffers
Swap:  2031608k total,  1303272k used,   728336k free,   476548k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
  229 root      10  -5     0    0    0 S    4  0.0  54:06.17 kswapd0
8693 root      18   0 2299m 1.3g  348 D    2 67.8   0:04.55 diff
17761 apache    18   0 12724 2580 1528 S    0  0.1   0:00.07 httpd
18730 root      15   0  2320 1128  804 R    0  0.1   0:00.04 top

From my understanding this diff script backing up maillog. I do not want to do this, how can I stop it ?