On Wed, 2 May 2007, Andrew Morton wrote:

quoted

This is a sensitive piece of the kernel as you say and we better allow the 
running of two allocator for some time to make sure that it behaves in all 
load situations. The design is fundamentally different so its performance 
characteristics may diverge significantly and perhaps there will be corner 
cases for each where they do the best job.

eek.  We'd need to fix those corner cases then.  Our endgame
here really must be rm mm/slab.c.

First we need to discover them and I doubt that mm covers much more than 
development loads. I hope we can get to a point where we have SLUB be 
the primarily allocator soon but I would expect various performance issues 
to show up.

On the other hand: I am pretty sure that SLUB can replace SLOB completely 
given SLOBs limitations and SLUBs more efficient use of space. SLOB needs 
8 bytes of overhead. SLUB needs none. We may just have to #ifdef out the 
debugging support to make the code be of similar size to SLOB too. SLOB is 
a general problem because its features are not compatible to SLAB. F.e. it 
does not support DESTROY_BY_RCU and does not do reclaim the right way etc 
etc. SLUB may turn out to be the ideal embedded slab allocator.

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>