Strange state of bind

[Daniel Ryslink]

Hello,

After further investigating the problems with BIND on our caching 
nameservers, I have find out that after several days of operation, BIND 
starts to eat 99% of CPU capacity, and ktrace shows that it does 
repeatedly this system call:

  41418 named    CALL  gettimeofday(0xbfbffa58,0)
  41418 named    RET   gettimeofday 0
  41418 named    CALL  gettimeofday(0xbfbfe9e8,0)
  41418 named    RET   gettimeofday 0
  41418 named    CALL  gettimeofday(0xbfbfea18,0)
  41418 named    RET   gettimeofday 0
  41418 named    CALL  gettimeofday(0xbfbfea98,0)
  41418 named    RET   gettimeofday 0
  41418 named    CALL  gettimeofday(0xbfbfea28,0)
  41418 named    RET   gettimeofday 0
  41418 named    CALL  gettimeofday(0xbfbfea28,0)
  41418 named    RET   gettimeofday 0
  41418 named    CALL  gettimeofday(0xbfbfea28,0)
  41418 named    RET   gettimeofday 0
  41418 named    CALL  gettimeofday(0xbfbfea28,0)
  41418 named    RET   gettimeofday 0
  41418 named    CALL  gettimeofday(0xbfbfea28,0)
  41418 named    RET   gettimeofday 0
  41418 named    CALL  gettimeofday(0xbfbfea28,0)
  41418 named    RET   gettimeofday 0
  41418 named    CALL  gettimeofday(0xbfbfea28,0)
  41418 named    RET   gettimeofday 0
  41418 named    CALL  gettimeofday(0xbfbfea28,0)
  41418 named    RET   gettimeofday 0
  41418 named    CALL  gettimeofday(0xbfbfea28,0)
  41418 named    RET   gettimeofday 0
  41418 named    CALL  gettimeofday(0xbfbfea28,0)
  41418 named    RET   gettimeofday 0
  41418 named    CALL  gettimeofday(0xbfbfea28,0)
  41418 named    RET   gettimeofday 0
  41418 named    CALL  gettimeofday(0xbfbfea28,0)
  41418 named    RET   gettimeofday 0
  41418 named    CALL  gettimeofday(0xbfbfea28,0)
  41418 named    RET   gettimeofday 0
  41418 named    CALL  gettimeofday(0xbfbfea28,0)
  41418 named    RET   gettimeofday 0
  41418 named    CALL  gettimeofday(0xbfbfea28,0)

Any ideas about what could cause this behavior?

Thanks.

Best Regards
Daniel Ryslink