Is it normal when kernel printed "xxx used greatest stack depth"

[hank peng]

On my MPC8548 based board, sometimes kernel printed out the following
messages, I wonder if it indicates the system is not normal?

pdflush used greatest stack depth: 4048 bytes left
pdflush used greatest stack depth: 4028 bytes left
pdflush used greatest stack depth: 3964 bytes left
pdflush used greatest stack depth: 3916 bytes left

-- 
The simplest is not all best but the best is surely the simplest!