What is the difference between l4dm_mem_allocate, l4slab_alloc, malloc

[chenggh]

Hi:
	In the l4vfs source code I am sure that the malloc function could be used in 
the L4 programming. But I also find two functions named  l4dm_mem_allocate 
and l4slab_alloc. It seems that both of them could also allocate memory as 
malloc does.
	What is the difference between the 3 functions? Which one is fastest? Please 
help me.
	Thank you.
											Cheng Guanghui