Backtrace nesting depth variable.
Info: This variable controls the depth of
the backtrace process which tries to find out the flow thru which
this leak was actually generated.
if you put n=0 then there is no backtracing done
the allocated address. more backtracing more effort on CPU.
TIP: to get really beautiful/useful backtrace
if it is possible to compile ur application with - rdynamic
option.