[Sheepdog] [PATCH 3/5] sheep: add a slab allocator

[Liu Yuan]

On 11/15/2011 04:04 PM, Christoph Hellwig wrote:

> Do you have any benchmarks to prove benefits?  I recently looked into
> using some sort of a slab allocator for xfs_repair, but in the end just
> using an efficient threading allocator (tcmalloc) proved to be a) much
> faster and b) use less memory.
> 


I am afraid, not yet. But I think it would be faster than raw
glibc-based malloc/free. Correct me if I am wrong, because I have a
impression that most APP would write its own alloc/free on top of glibc
malloc/free.

As for tcmalloc, I think it is implementation specific, and just have a
quick look at the overview of it, it should be efficient than the simple
& dumb slab allocator above.

But I think we can only provide tcmalloc as an option to user, since not
every one have tcmalloc installed. So even we choose to use tcmalloc, we
have to write a wrapper to abstract out tcmalloc and glibc malloc away.

Being that said, we need an wrapper interface and the above

	id = slabs_clsid(object size); # this will preallocate a slab sized by
object size. 	
	object_ptr = slabs_alloc(id);
	slabs_free(object_ptr, id);

would be an good starting point.

Thanks,
Yuan