Re: [B.A.T.M.A.N.] kmalloc() vs. kmem_cache_alloc() for global TT?

[Sven Eckelmann <sven@narfation.org>]

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On Saturday 14 May 2016 16:51:29 Linus Lüssing wrote:
> Hi,
> 
> Is anyone familiar with the implications of using kmalloc() vs.
> kmem_cache_alloc()? Not just allocation speed, but also RAM
> fragmentation is something I'm currently wondering about.

Yes, it should reduce the effects of allocating differently sized objects 
(which can create smaller regions of memory which cannot be used anymore). But 
my guess is that SLAB isn't that bad because it already has some caches for 
differently sized memory regions.

I think we should check if this helps by first testing it with the main TT 
objects. I've send an RFC patch [1]. Unfortunately, I am not aware of any nice 
tools to really check the size of the available, continuous memory chunks. The 
only thing partially interesting I know about is /proc/slabinfo which shows 
you the state of the available caches (including the slab page caches).

Kind regards,
	Sven 

[1] https://patchwork.open-mesh.org/patch/16200/

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