SLAB allocator now the default.

[David Leimbach]

On Sep 28, 2003, at 9:22 AM, Hiten Pandya wrote:

Matthew Dillon wrote:

    The slab allocator is now the default.  The NO_KMEM_MAP and
    USE_SLAB_ALLOCATOR options have been removed.
    USE_KMEM_MAP and NO_SLAB_ALLOCATOR options have temporarily been 
added,
    but these too will be removed (along with the old malloc and 
kmem_map
    code) in about a week.


Hiten,

	Matt,

	I haven't looked at the Slab-alloc code recently, but I am
	wondering if you are planning to remove the power-of-2 alignment
	stuff out of malloc()?
Doesn't power of two alignment make it easier on some CPUs internally 
to access
data?  If a person wanted to access a word overlapping two word's 
alignment would it
not take two bus accesses to get that data [or two cache reads... what 
have  you]

Do the benefits of not having power of two alignment outweigh this?



	From the many papers I have been reading in the last couple of
	weeks, it seems that power-of-2 alignment seems to cause a lot
	of performance degradation in SMP cases, and cache issues.
	A good example of this demonstration is in Bonwick's papers.

	I understand this would be quite a lengthy and tedious procedure
	but it is something that I have been wondering.
	Regards,

--
Hiten Pandya
hmp at xxxxxxxxxxxxx